Sunday, August 31, 2014

Build a Low Noise And Drift Composite Amp Wiring diagram Schematic

How to Build a Low Noise And Drift Composite Amp Circuit Diagram. This schema offers the best of both worlds. It can be combined with a low input offset voltage and drift without degrading the overall system`s dynamic performance. 

 Low Noise And Drift Composite Amp Circuit Diagram



Low

Compared to a standalone FET input operational amplifier, the composite amplifier schema exhibits a 20-fold improvement in voltage offset and drift. In this schema arrangement, A1 is a highspeed FET input op amp with a closed-loop gain of 100 (the source impedance was arbitrarily chosen to be 100 kfl). A2 is a Super Beta bipolar input op amp. It has good dc characteristics, biFET-level input bias current, and low noise. A2 monitors the voltage at the input of A1 and injects current to Al`s null pins. This forces A1 to have the input properties of a bipolar amplifier while maintaining its bandwidth and low-input-bias-current noise.

2008 Mazda 3 Wiring Diagram

2008 Mazda 3 Wiring Diagram
The part of 2008 Mazda 3 Wiring Diagram: illumination light, main fuse block, relay diagram, panel light control switch, ashtray illumination, panel light control switch, glove compartment, instrument cluster, data link connector, coil antenna, fuel gauge sender unit, micro computer, ignition key illumination, main  fuse block, water temperature gauge, speedometer, tachometer, fuel gauges, micro computer, odometer, brake fluid level sensor, parking brake switch, washer, washer fluid level sensor, audio unit, LCD unit, hazard warning switch, navigation system, cigarette lighter illumination, selector illumination, climate control unit, keyless control module.

Simple Function Generator Wiring diagram Schematic

Simple


This is a simple function generator schema that can produce the following waveforms: square wave, triangular wave, and sine wave.
The diagram main components are two 1458 ICs.  The 1458 is a dual op-amp IC, i.e., an IC that houses two op amps inside it.  The schema uses four op amps, two from each 1458.
The bottom-most op amp in Figure 1 is configured as an astable multivibrator, which continuously generates a square wave.  Assume that C1 has no charge initially. The voltage at the inverting input is zero, while the voltage at the non-inverting input is very slightly positive (a ratio of the op amps output offset voltage as determined by R1 and R2). This minute voltage difference at the inputs is enough to cause the op amps output to swing to high.
When the output becomes high, C1 starts charging up. The voltage at the inverting input soon exceeds that at the non-inverting input, forcing the output to swing to low, which discharges C1 again.  At a certain point, the voltage at the non-inverting input exceeds that at the inverting input again, and the output of the op amp goes high again.
This cycle wherein the first op amps output swings between low and high goes on indefinitely, generating the square wave.
The two middle op-amps are both configured as integrators. The input to the second op amp is the square wave output of the first op amp.  Being configured as an integrator, this op amp outputs a triangular wave (the integral of a square wave), as shown in Figure 1. 
The triangular wave output of the second op amp is then fed into the third op amp, which is also configured as an integrator.  The output of the third op amp is a sine wave (the integral of a triangular wave).
The sine wave output of the third op amp is fed into the fourth op amp, which is configured as an inverting amplifier. The output of this last op amp is also a sine wave but opposite in phase as its input.

Build a 1000W Power Amplifier Wiring diagram Schematic

This is a like full 1000W Power Amplifier Circuit Diagram. I think youve seen or even have an active speaker and there is written 1500 watts PMPO (Peak Music Power Output), make no mistake this is different from Power Amplifier Active Speaker, I often dismantle such Active Speaker in it only a power with power no more than 150 watts by using the transformer 2-3 Ampere. PMPO is not a real power which is issued by the Power Amplifier, but counting all the speakers that there is, for example: if there are 5 pieces of speakers on each channel and each speaker has a power of 10 W then it is 100 W PMPO.

1000W Power Amplifier Circuit Diagram

1000W

 While this 1000 Watt Power Amplifier minimal use transformer 20 Ampere. And the output of Power Amplifier DC voltage contains approximately 63 volts, with currents and voltages of this magnitude, this 1000 Watt Power Amplifier will not hesitate hesitate to destroy your woofer speakers to connect. To overcome that then before the speaker on connects to 1000 Watt Power Amplifier must be in pairs Speaker Protector.

Actually if you want to create a Power Amplifier with great power does not have to make a Power Amplifier with great power. Example: you want to create a Power Amplifier with 10 000 Watt power. You do not have to assemble a Power Amplifier with power of 10,000 watts, but you assemble the power Power Amplifier Small but many, such as you assemble the Power Amplifier with 1000 Watts of power for as many as 10 pieces, it will produce 10 000 Watt Power Amplifier helpless.

Parts List

Circuit uses power transistors pair of 5 x 5 x 2SA1216 and 2SC2922 and 2SC1583 use a differential amplifier that actually contains 2 pieces of transistors that are in containers together. Why use such built-in amplifier differental tujuanya so identical / similar, could have uses 2 separate transistors but can result in amplifier so it is not symmetrical.

Tips combining speaker

Tips

To get the speakers with great power combining techniques can be used in parallel series, combining each group of speakers should sepaker they will have the same impedance, the same type (Woofer, Mid Range or tweeter) and the same power. Number of merging these speakers should consists of 4 , 9, 16 ff, see picture

Example
The number of speakers have 4 pieces each of its 200 Watt power generated will be a speaker at = 200 x 4 = 800 Watt. If there are 9 speakers 200 W then the result = 9 x 200 W = 1800 Watt.

NE 555 Pulse generator


Most of our members asked pulse generator diagram. so this is a simple and common schema.and you can use this with your light schema diagrams too.





Note

# Dont supply more than 15V

Factory Siren

This schema produces a sound similar to a factory siren.It makes use of a 555 timer Ic used as an astable multivibrator of a center frequency of about 300Hz.The frequency is controlled by the pin 5 of the IC



http://www.electronic-diagram-diagrams.com/alarmsimages/15.gif





When the supply is switched ON, the capacitor charges slowly and this alters the voltage at pin 5 of the IC hence the frequenct gradually increases.
After the capacitor is fully charged, the frequency no longer increases. Now when the push button siren control switch is held depressed, the capacitor discharges and the siren frequency also decreases.
The presets VR1 and VR2 should be adjusted for optimum performance.

4 Bit Analogue to Digital Converter

The operation of the converter is based on the weighted adding and transferring of the analogue input levels and the digital output levels. It consists of comparators and resistors. In theory, the number of bits is unlimited, but each bit needs a comparator and several coupling resistors. The diagram shows a 4-bit version. The value of the resistors must meet the following criteria:
  • R1:R2 = 1:2;
  • R3:R4:R5 = 1:2:4;
  • R6:R7:R8:R9 = 1:2:4:8.
The linearity of the converter depends on the degree of precision of the value of the resistors with respect to the resolution of the converter, and on the accuracy of the threshold voltage of the comparators. This threshold level must be equal, or nearly so, to half the supply voltage. Moreover, the comparators must have as low an output resistance as possible and as high an input resistance with respect to the load resistors as feasible. Any deviation from these requirements affects the linearity of the converter adversely.
4-Bit

4-Bit Analogue to Digital Converter Circuit Diagram

If the value of the resistors is not too low, the use of inverters with an FET (field-effect transistor) input leads to a near-ideal situation. In the present converter, complementary metal-oxide semiconductor (CMOS) inverters are used, which, in spite of their low gain, give a reasonably good performance. If standard comparators are used, take into account the output voltage range and make sure that the potential at their non-inverting inputs is set to half the supply voltage. If high accuracy is a must, comparators Type TLC3074 or similar should be used. This type has a totem-pole output. The non-inverting inputs should be interlinked and connected to the tap of a a divider consisting of two 10 kΩ resistors across the supply lines. It is essential that the converter is driven by a low-resistance source. If necessary, this can be arranged via a suitable op amp input buffer. The converter draws a current not exceeding 5 mA.

Saturday, August 30, 2014

Small Audio Amplifiers Using LM386 and NE5534

Many electronic projects require the use of a small audio amplifier. Be it a radio transceiver, a digital voice recorder, or an intercom, they all call for an audio amp that is small, cheap, and has enough power to provide adequate loudness to fill a room, without pretending to serve a disco! About one Watt RMS seems to be a convenient size, and this is also about the highest power that a simple amplifier fed from 12V can put into an 8 Ohm speaker. A very low saturation amplifier may go as high up as 2 Watt, but any higher power requires the use of a higher voltage power supply, lower speaker impedance, a bridge schema, or a combination of those.

During my many years building electronic things I have needed small audio amps many times, and have pretty much standardized on a few IC solutions, first and and foremost the LM386, which is small, cheap, and very easy to use. But it does not produce high quality audio... For many applications, the advantages weigh more than the distortion and noise of this chip, so that I used it anyway. In other cases I used different chips, which perform better but need more complex diagram. Often these chips were no longer available the next time I needed a small amplifier.

When I last upgraded my computer, I replaced the old and trusty Soundblaster AWE 32 by a Soundblaster Audigy. The new card is better in many regards, but while the old one had an internal audio power amplifier, the new one doesnt! Thats bad news, because I have some pretty decent speakers for the PC, which are fully passive. So, I built a little stereo amp using two LM386 chips and installed it inside the computer, fed by the 12V available internally.

But then I wasnt satisfied. The LM386 might be suitable for "communication quality" audio, which is roughly the fidelity you get over a telephone, but for music its pretty poor! The distortion was awful. So, the day came when I decided to play a little more scientifically with small audio amps, looking for a way to get good performance with simple and inexpensive means.

I set up a test bench with a sine wave oscillator running at 1 kHz, an 8 Ohm speaker, 12V power supply, and the computer with the soundcard and Fast Fourier Transform software. One channel was connected to the oscillator together with the amplifier input, the other channel to the output and speaker. With this setup I measured the harmonic content of the audio signals. I did the tests at an output level of 0.1W, which is typical for moderately loud sound from a reasonably efficient speaker. Also, I used a music signal from a CD player to test the actual sound of each amplifier.

Circuit

As already said above, the main attraction of the LM386 is the extreme simplicity of its application schema. You can even eliminate R1 if the signal source is DC-grounded. If the speaker leads are long, you should add an RC snubber across the output to aid stability. Additionally, if you need higher gain (not necessary if the input is at line level), you can connect a 10uF capacitor between pins 1 and 8. Thats about all there is to it.

Now the bad news: This schema produced a very high level of distortion! The second harmonic measured just -28dB from the main output. The third harmonic was at -35dB, while the noise level was at -82dB. There were assorted high harmonics at roughly -45dB. With music, the distortion was really disturbing, and also the noise level was uncomfortably high. The power supply rejection is poor, so that some hum and other supply noise gets through. In short, this was a lousy performance!

Since I had used so many LM386s in my projects, I had several different variations. In my material box I found a slightly newer LM386N-1. So I plugged it into my test amplifier. It was even worse! The second harmonic was at -24dB, the third harmonic at -31dB, while the noise was a tad better at -84dB. Folks, thats a total harmonic distortion of almost 7%! And the 0.1W output level at which this was measured is where such a schema is about at its best...  The distortion can be plainly seen on the oscilloscope, and a visibly distorted waveform is about the most offending thing an audio designer can ever see!

Looking through my projects, I found one where I had used a GL386 chip. This is just a 386 made by another company. I unsoldered it and put it in my test amplifier. Surprise! It was dramatically better, with the second harmonic at -45dB, and the third at -57dB! The noise floor was -84dB, just like the LM386N-1. But even this level of distortion was plainly audible when listening to music. Thats roughly 0.6% THD. Some folks may consider it acceptable for music. I dont, but for communication equipment its fine. At this point, I decided to see if I could build a better amplifier, that doesnt become too complex nor expensive.

Circuit

This was the first attempt. A low distortion, fast slew rate, but easy to find and rather inexpensive operational amplifier, driving a simple source follower made of two small transistors. These transistors are not biased, so they work at zero quiescent current, in full class B. The only mechanism that works against crossover distortion here is the high slew rate of the OpAmp, which is able to make the distortion bursts during crossover very short. To say the truth, I didnt expect to get usable performance from this schema, and was really surprised when it worked much better than the 386! The second harmonic was at -77dB, the third at -79dB!

Also there were many high harmonics at roughly -84dB. That means a THD of about 0.015%.  The noise floor was down at the -120dB level! The power supply rejection was excellent, with no detectable feedtrough. Playing music, this amplifier sounded really good: No audible noise, and the distortion could be heard when paying attention to it, but I doubt that the average person would detect it! Not bad, for a bias-less design!

Just to see how important the slew rate of the OpAmp is, I pulled out the NE5534 and replaced it by a humble 741, which is many times slower. The result was dramatic: The second harmonic still good at -70dB, but the third harmonic was much worse, at -48dB. Also there were many high harmonics at the same -48dB level. Given that second harmonic distortion doesnt sound bad to most people, but third harmonic does, and high harmonics are even worse, it came as no surprise that the amplifier with the 741 sounded bad.

At low volume it sounded particularly bad! So I returned to the oscillator and measurement setup, testing at lower output power, and found that while the second and third harmonics followed the output, the high harmonics stayed mostly constant! So, at very low output, the high harmonics became very strong relative to the output. All this is the effect of the slower slew rate of the 741, which makes it less effective correcting the crossover distortion of the unbiased transistors. Interestingly, the noise floor of the 741 schema wasnt bad: -118dB.

Just for fun, I tried this schema with a third OpAmp: The TL071, which is good, but not as good as the 5534. The results: Second harmonic at -72dB, third and the high ones at -60dB, and the noise at -120dB. Its interesting that the second harmonic is much more suppressed than the third one. That must be a balancing effect of the symmetric output stage, and the better symmetry in the TL071 compared to other OpAmps.

Its worthwhile to note that this amplifier can be simplified a lot by using a split power supply. R1, R2, C1, C2 and C4 would be eliminated! But then you need the capacitor removed from C4 to bypass the negative supply line. The positive input of the chip goes to ground, while pin 4 and the collector of Q2 go to the negative supply. The rest stays the same. If you use a +-15V supply, the available RMS output power grows to over 10 Watt! Of course, you then need larger transistors. And since larger transistors are slower, the distortion will rise somewhat. An added benefit of a split supply is that the popping noise when switching on and off is eliminated.

Circuit

As the next experiment, I decided to get rid of the crossover distortion. For this purpose, I added a traditional adjustable bias schema with a transistor and a trimpot. Now I also had to add a current source, because with the bias schema there is no single point into which the OpAmp could put its drive current into both bases! I adjusted the bias for the best distortion, and this was really  a good one! The second harmonic was down right where the test oscillator delivered it, about -80dB, so I couldnt really measure it!

The third harmonic was at -84dB, and the best improvement was that the higher harmonics had simply disappeared! They were all below the noise floor, which stayed at -120dB. Actually, this noise floor seems to come from the soundcard A/D converter, so that the actual noise of this and the above amplifier may even be better! With music, this amplifier sounded perfect - clean and smooth. And Im pretty confident that the THD is well below the limits of my measurement setup, which is 0.01%.

The quiescent current was around 10mA. When lowering it to about 3mA, the high harmonics started to rise out of the noise floor. If you want to adjust the bias for the exact best quiescent current, there is a simple trick: Lift R4 from the output, and connect it to pin 6. Now the output stage has been left outside the feedback loop, and all its distortion will show up at the output. Watching the signal on an oscilloscope, or even better on a real time spectrum analyzer (soundcard and software), adjust the trimpot to the lowest distortion level.

Have a current meter in the supply line and make sure that you dont exceed 30mA or so of quiescent current, in order to keep the small transistors cool. But most likely the best distortion will be at a current lower than that. Once the adjustment is complete, return R4 to its normal position. Now the full gain and slew rate of the operational amplifier is used to correct the small remaining cross-over distortion of the output stage, and the distortion will certainly disappear from the scope screen, from your ears, and possibly fall below the detection level of the spectrum analyzer!

This schema can also be run from a split power supply, by exactly the same mods as for the previous schema. And since the transistors are properly biased, there isnt any significant distortion increase when using larger transistors. Be sure to use some that have enough gain - you have only a few mA of driving available, and with a +-15V power supply and an 8 Ohm speaker, there can be almost 2A of output current! So, you need a gain of 300 at least. There are power transistors in the 4A class that provide such gain, and these are good candidates. The other option is using Darlington transistors, which far exceed the gain needed here. But they will again increase the distortion, not very much, but perhaps enough to make it audible again.
Source: Humo Luden

Audio Power Meter Wiring diagram Schematic

This is an audio power meter simple with this schema, dual LED starts to light green around 0.1 watts into 8 ohms (0.2 watt into 4 ohms). Naturally, this depends on the specific type of LED is used. Despite being a simple equipment he is impressively bench since with a load resistor connected to output of speakers is possible to measure the sound level up, or just check its output.


Audio Power Meter Circuit Diagram

Audio

Infra red Level Detector

This schema is useful in liquids level or proximity detection. It operates detecting the distance from the target by reflection of an infra-red beam. It can safely detect the level of a liquid in a tank without any contact with the liquid itself. The devices range can be set from a couple of cm. to about 50 cm. by means of a trimmer.Range can vary, depending on infra-red transmitting and receiving LEDs used and is mostly affected by the color of the reflecting surface. Black surfaces lower greatly the devices sensitivity.




Level



Parts:


R1_____________10K 1/4W Resistor
R2,R5,R6,R9_____1K 1/4W Resistors
R3_____________33R 1/4W Resistor
R4,R8___________1M 1/4W Resistors
R7_____________10K Trimmer Cermet
R10____________22K 1/4W Resistor


C1,C4___________1µF 63V Electrolytic or Polyester Capacitors
C2_____________47pF 63V Ceramic Capacitor
C3,C5,C6______100µF 25V Electrolytic Capacitors

D1_____________Infra-red LED
D2_____________Infra-red Photo Diode (see Notes)
D3,D4________1N4148 75V 150mA Diode
D5______________LED (Any color and size)
D6,D7________1N4002 100V 1A Diodes

Q1____________BC327 45V 800mA PNP Transistor

IC1_____________555 Timer IC
IC2___________LM358 Low Power Dual Op-amp
IC3____________7812 12V 1A Positive voltage regulator IC

RL1____________Relay with SPDT 2A @ 220V switch
Coil Voltage 12V. Coil resistance 200-300 Ohm

J1_____________Two ways output socket





IC1 forms an oscillator driving the infra-red LED by means of 0.8mSec. pulses at 120Hz frequency and about 300mA peak current. D1 & D2 are placed facing the target on the same line, a couple of centimeters apart, on a short breadboard strip. D2 picks-up the infra-red beam generated by D1 and reflected by the surface placed in front of it. The signal is amplified by IC2A and peak detected by D4 & C4. Diode D3, with R5 & R6, compensates for the forward diode drop of D4. A DC voltage proportional to the distance of the reflecting object and D1 & D2 feeds the inverting input of the voltage comparator IC2B. This comparator switches on and off the LED and the optional relay via Q1, comparing its input voltage to the reference voltage at its non-inverting input set by the Trimmer R7.


Notes:

* Power supply must be regulated (hence the use of IC3) for precise reference voltage. The schema can be fed by a commercial wall plug-in adapter, having a DC output voltage in the range 12-24V.
* Current drawing: LED off 40mA; LED and Relay on 70mA @ 12V DC supply.
* R10, C6, Q1, D6, D7, RL1 and J1 can be omitted if relay operation is not required.
* The infra-red Photo Diode D2, should be of the type incorporating an optical sunlight filter: these components appear in black plastic cases. Some of them resemble TO92 transistors: in this case, please note that the sensitive surface is the curved, not the flat one.
* Avoid sun or artificial light hitting directly D1 & D2.
* Usually D1-D2 optimum distance lies in the range 1.5-3 cm.

Simple Equipment on reminder Wiring diagram Schematic

This is an Equipment on reminder Circuit Diagram. Due to the low duty cycle of flashing LED, the average current drain is 1 mA or less.


Equipment on reminder Circuit Diagram

Equipment

Build a Charger Extends Lead Acid Battery Life Wiring diagram Schematic

The Charger Extends Lead-Acid Battery Life Circuit Diagram furnishes an initial charging voltage of 2.5 V per cell at 25°C to rapidly charge a battery. The charging current decreases as the battery charges, and when the current drops to 180 mA, the charging schema reduces the output voltage to 2.35 V per cell, floating the battery in a fully charged state. 

This lower voltage prevents the battery from overcharging, which would shorten its life. The LM301A compares the voltage drop across R1 with an 18-mV reference set by R2. The comparator`s output controls the voltage regulator, forcing it to produce the lower float voltage when the battery-chaiging current passing through R1 drops below 180 mA. the 150-mV difference between the charge and float voltages is set by the ratio of R3 to R4. The LEDs show the state of the schema . 

Charger Extends Lead-Acid Battery Life Circuit Diagram

Charger

Touch Switch II

This schema uses a 555 timer as the bases of the touch switch. You can learn more about 555 timers in the Learning section on my site. When the plate is touched the 555 timer is triggered and the output on pin 3 goes high turning on the LED and the buzzer for a certain period of time. The time that the LED and the buzzer is on is based on the values of the capacitor and resistor connected to pin 6 & 7. The 10M resistor on pin 2 causes the the schema to be very sensitive to the touch.

Friday, August 29, 2014

Transistor As a timer circuit

Basically on all timer or timer circuit utilizing most of the basic characteristics of the capacitor.

Transistor

 The basic characteristic is the process of filling and discharge that occurs in the capacitor. The length of time charging and release depends on the value of the capacitor.


If we observe the above circuit, the light will immediately switch SW1 turns on when we plug it into potensio VR1, this is because the current flowing from VR1 to trigger the transistor base should fill the first capacitor C1. Semakian large capacitance value of C1 then the longer the time required by the transistor to turn on the lights. Then if we connect it to the Ground SW1 then light would soon die and the capacitor will immediately clear the cargo. So can we draw the conclusion that the transistor can be used as a timer circuit using capacitor charging and discharging properties.

Build a Voltage Regulator 12v to 24v using 7812

How to build a voltage regulator 12v to 24v using 7812. What many people do not know is it possible for a voltage regulator IC to provide an output voltage higher than its actual value. One method to achieve this is by connecting the "common" terminal to the middle point of a potential divider, but the problem with this method is that the regulators IC has a small quiescent current (~ 10 mA) flowing out the common terminal to ground.

The schema presented here avoids the problems of using the IC regulator to raise the voltage via the transistor Q1 to generate a low impedance to the common terminal video controller during the transfer of the voltage divider from a resistor divider network relatively high. The value of R3 is not critical, but should be low enough to accept the higher quiescent current without causing problems for T1.

Voltage Regulator 12v to 24v Circuit Diagram 

Voltage

Vocal Adaptor for Bass Guitar Amp

These days, music is a major hobby for the young and not-so-young. Lots of people  enjoy  making  music,  and  more  and  more dream of showing off their talents on stage. But one of the major problems often encountered is the cost of musical equipment. How many amateur music groups sing  through an amp borrowed from a guitarist or bass player?
This is where the technical problems arise not in terms of the .25” (6.3 mm)  jack, but in terms of the sound quality (the words  are barely understandable) and volume (the amp  seems to produce fewer decibels than for a guitar). What’s more, unpredictable feedback may cause damage to the speakers and is very unpleasant on the ear. This cheap little  easy-to-build project can help solve these technical  problems.

Vocal
Vocal Adaptor for Bass Guitar Amp Circuit Diagram
A guitar (or bass guitar) amplifier is designed first and foremost to reproduce the sound of the guitar or bass as faithfully as  possible. The frequency response of the amp doesn’t need to be as wide or as flat as in hi-fi (particularly at the high end), and so this sort of amplifier won’t permit faithful reproduction of the voice. If you build an adaptor to compensate for the amp’s limited frequency response by amplifying in advance the frequencies that are  then attenuated by the amp, it’s possible to  improve the quality of the vocal sound. That’s  just what this schema attempts to do.
The adaptor is built around the TL072CN low-noise dual FET op-amp, which offers good value for money. The NE5532 can be used with almost the same sound quality, but at (slightly) higher cost. The schema breaks  down into two stages. The first stage is used to match the input impedance and amplify the microphone signal. For a small 15 W guitar or bass amplifier, the achievable gain is  about 100 (gain = P1/R1). For more powerful amplifiers, the gain can be reduced to  around 50 by adjusting P1. The second stage amplifies the band of frequencies (adjustable using P2 and P3) that are attenuated by the guitar amp, so as to be able to reproduce the (lead)  singer ’s voice as clearly, distinctly, and  accurately as possible. To refine the adaptor and tailor it to your amplifier and speaker, don’t be afraid to experiment with the component values and the type  of capacitors.
The schema can readily be powered using a 9 V battery, thanks to the voltage divider R4/R5 which converts it into a symmetrical  ±4.5 V supply.

Author : Jérémie Hinterreiter

IR Remote Control Tester

A 741 or LF351 will not work in this schema. Although I have used a 12 volt power supply, a 9 volt battery will also work here.






As I was developing my IR Extender Circuit, I needed to find a way of measuring the relative intensities of different Infra red light sources. This schema is the result of my research. I have used a photodiode, SFH2030 as an infra red sensor. A MOSFET opamp, CA3140 is used in the differential mode to amplify the pulses of current from the photodiode. LED1 is an ordinary coloured led which will light when IR radiation is being received. The output of the opamp, pin 6 may be connected to a multimeter set to read DC volts. Infra red remote control strengths can be compared by the meter reading, the higher the reading, the stronger the infra red light. I aimed different remote control at the sensor from about 1 meter away when comparing results. For every microamp of current through the photodiode, about 1 volt is produced at the output

Simple Rf Probe Wiring diagram Schematic For vtvm

This Simple Rf Probe Circuit Diagram combines a 555 timer with a 2N2222 transistor and an external potentiometer. The pot adjusts the output voltage to the desired value. To regulate the output voltage, the 2N2222 varies the control voltage of the 555 IC, increasing or decreasing the pulse repetition rate. A 1 K resistor is used as a collector load. The transistor base is driven from the external pot. 

Simple Rf Probe Circuit Diagram

Simple

If the output voltage becomes less negative, the control voltage moves closer to ground, causing the repetition rate of the 555 to increase, which, in turn, causes the 3 µf capacitor to charge more frequently. Output voltage for the schema is 0 to 10 V, adjusted by the external pot. Output regulation is less than five percent for 0 to 10 mA and less than 5 percent for 0 to 0 mA.

Electrical Isolation For I2C Bus Wiring diagram Schematic

When the SDA (Serial DAta) lines on both the left and right lines are 1, the schema is quiescent and optoisolators IC1 and IC2 are not actuated. When the SDA line at the left becomes 0, current flows through the LED in IC1 via R2. The SDA line at the right is then pulled low via D2 and IC1. Optoisolator IC2 does not transfer this 0 to the left, because the polarity of the LED in IC2 is the wrong way around for this level. This arrangement prevents the schema holding itself in the 0 state for ever. As is seen, the schema is symmetrical. So, when the SDA line at the right is 0, this is transferred to the left. The lower part of the diagram, intended for the SCL (Serial CLock) line, is identical to the upper part.

Electrical Isolation For I2C Bus Circuit diagram :


Electrical
Electrical Isolation For I2C Bus Circuit Diagram

Resistors R1, R4, R5, and R8, are the usual 3.3 kΩ pull-up resistors that are obligatory in each I2C line. If these resistors are already present elsewhere in the system, they may be omitted here. The current drawn by the schema is slightly larger than usual since the pull-up resistors are shunted by the LEDs in the optoisolators and their series resistors. Nevertheless, it remains within the norms laid down in the I2C specification.
Source by : streampowers

Thursday, August 28, 2014

Parallel Connecting Solar Panels


Parallel Connecting Solar Panels

12V to 24V Simple DC Converter Circuit


12V to 24V Simple DC Converter Circuit

A acquaintance of me wants the ambit enhances Voltage 12VDC from be 24VDC or DC to DC Converter 12V to 24V. By fix acknowledge that be the ambit is simple , body not difficult. I afresh admonish this ambit try out anticipate use aloof Transistors D1616 = 2 pcs. with agent the small-sized , mix with added accessories a little alone again. Follow a account has can to use this ambit with baby fan motor.

Long range Burglar Alarm Using Laser Torch

Laser torch-based burglar alarms normally work in darkness only. But this long-range photoelectric alarm can work reliably in daytime also to warn you against intruders in your big compounds, etc. The alarm comprises laser transmitter and receiver units, which are to be mounted on the opposite pillars of the entry gate. Whenever anyone enters to interrupt the transmitted laser beam falling on the receiver, the buzzer in the receiver schema sounds an alarm.

The range of this burglar alarm is around 30 metres, which means you can place the transmitter and the receiver up to 30 metres apart. Since the laser torch can transmit light up to a distance of 500 metres, this range can be increased by orienting the phototransistor sensor properly. To avoid false triggering by sunlight, mount the phototransistor sensor such that it doesn’t directly face sunlight.

Circuit
Fig. 1: Circuit of laser torch based transmitter

The transmitter schema is powered by 3V DC. The astable multivibrator built around timer 7555 (IC1) produces 5.25kHz frequency. CMOS version of timer 7555 is used for low-voltage operation. The body of the laser torch is connected to the emitter of npn transistor T1 and the spring-loaded lead protruding from inside the torch is connected to the ground.

The receiver schema is powered by 12V DC. It uses photoDarlington 2N5777 (T2) to sense the laser beam transmitted from the laser torch. The output beam signals from photoDarlington are given to the two-stage amplifier followed by switching schema, etc. As long as the laser beam falls on photoDarlington T2, relay RL1 remains un-energised and the buzzer does not sound. Also, LED1 doesn’t glow.

Receiver
Fig. 2: Receiver schema

When anyone interrupts the laser beam falling on photoDarlington T2, npn transistor T6 stops conducting and npn transistor T7 is driven into conduction. As a result, LED1 glows and relay RL1 energises to sound the buzzer for a few seconds (determined by the values of resistor R15 and capacitor C10). At the same time, the large indication load (230V AC alarm for louder sounds or any other device for momentary indication) also gets activated as it is connected to 230V AC mains via normally opened (N/O) contact of relay RL1.


Sourced By: EFY Author: Pradeep G.

Mini Portable Guitar Amplifier

Can be fitted into a packet of cigarettes, Also suitable as Fuzz-box
This small amplifier was intended to be used in conjunction with an electric guitar to do some low power monitoring, mainly for practice, either via an incorporated small loudspeaker or headphones. The complete schema, loudspeaker, batteries, input and output jacks can be encased in a small box having the dimensions of a packet of cigarettes, or it could be fitted also into a real packet of cigarettes like some ready-made units available on the market.

This design can be used in three different ways:
  • Loudspeaker amplifier: when powered by a 9V alkaline battery it can deliver about 1.5W peak output power to the incorporated loudspeaker.
  • Headphone amplifier or low power loudspeaker amplifier: when powered by a 3V battery (2x1.5V cells) it can drive any headphone set type at a satisfactory output power level or deliver to the incorporated loudspeaker about 60mW of output power. This configuration is useful for saving battery costs.
  • Fuzz-box: when powered by a 3V battery (2x1.5V cells) and having its output connected to a guitar amplifier input the schema will behave as a good Fuzz-box, showing an output square wave with marked rounded corners, typical of valve-diagram output when driven into saturation.
Circuit diagram:
Mini
Mini Guitar Amplifier Circuit Diagram
Parts:
R1__________22K 1/4W Resistor
C1__________10µF 25V Electrolytic Capacitor
C2__________100nF 63V Polyester or Ceramic Capacitor
C3__________220µF 25V Electrolytic Capacitor
IC1_________TDA7052 Audio power amplifier IC
J1,J2_______6.3mm Stereo Jack sockets (switched)
SPKR_______8 Ohm Loudspeaker (See Notes)
B1_________9V PP3 Battery or 3V Battery (2 x 1.5V AA, AAA Cells in series etc.)
Clip for PP3 Battery or socket for 2 x 1.5V AA or AAA Cells
Notes:
  • For the sake of simplicity and compactness, this unit employs a dual bridge IC amplifier and a few other parts. For the same reason no volume or tone controls are provided as it is supposed that the controls already existing on the electric guitar will serve satisfactorily to the purpose.
  • No power switch is used: the battery voltage will be applied to the schema when the input plug will be inserted in the input jack socket J1. For this purpose be sure that the input plug is a common 1/4 inch guitar mono jack plug and J1 is a 1/4 inch stereo jack socket.
  • The output jack socket J2 must be a switched stereo type. The changeover switching is arranged in such a way that, when a common headphones stereo jack plug is inserted into the socket, the loudspeaker will be disabled and the mono output signal will drive both the headsets in series, allowing full headphone reproduction. When used as a Fuzz-box output, a mono jack plug must be inserted into J2.
  • If the amplifier is intended to be encased in a packet of cigarettes, standard loudspeaker diameter should be 57 or 50mm.
Technical data:
Max output power: 1.5W @ 9V supply - 8 Ohm load; 60mW @ 3V supply - 8 Ohm load
Frequency response: Flat from 20Hz to 20kHz
Total harmonic distortion @ 100mW output: 0.2%
Max input voltage @ 3V supply: 8mV RMS
Minimum input voltage for Fuzz-box operation: 18mV RMS @ 3V supply
Current consumption @ 400mW and 9V supply: 200mA
Current consumption @ 250mW and 9V supply: 150mA
Current consumption @ 60mW and 3V supply: 80mA
Quiescent current consumption: 6mA @ 9V, 4mA @ 3V supply
Fuzz-box current consumption: 3mA @ 3V supply

PWM Based Speed Control for DC Motors

There are several methods for controlling the speed of DC motors. One simple method is to add series resistance using a rheostat. As considerable power is consumed in the rheostat, this method is not economical. Another method is to use a series switch that can be closed/opened rapidly. This type of control is termed as chopper control. We’ve described here a PWM-based chopper schema that smoothly controls the speed of general-purpose DC motors.

Block

Fig.1: Block diagram of PWM-based speed controller

Fig. 1 shows the block diagram of a basic PWM-based chopper. The schema shown in Fig. 2 is designed as per this diagram. A dual timer IC (NE556) is used to configure both the astable as well as the monostable multivibrator. Timing components for the astable are chosen to provide a frequency of 546 Hz, while the monostable components are selected to obtain a maximum pulsewidth of 2.42 ms. Diode D1 improves duty factor of the astable oscillator output, whereas D2 acts as a free-wheeling diode. Transistor SL100 drives the motor, while the 22-ohm, 2W resistor (R4) serves as a current limiter, avoiding overheating of the transistor. The DPDT switch enables direction reversal of the motor, as desired.

The

Fig. 2: The schema of PWM-based speed controller

The speed can be varied by adjusting VR1, which changes the threshold value to which capacitor C1 in the monostable schema is charged. This, in turn, determines its output pulsewidth and hence the average voltage applied to the motor. Waveforms shown in Fig. 3 depict the average voltage for controlling various speeds.

For effective speed control, ‘on’ period (TON) of the astable should be equal to the maximum pulsewidth (TON) of the monostable.

Waveforms

Fig. 3: Waveforms at different conditions of VR1

For higher voltage and power requirements, SL100 can be replaced by an appropriate MOSFET or IGBT with relevant changes in the drive schemary.

The schema costs around Rs 75.

Interior Light Fader for Automobile

Interior

Here the schema diagram of Interior Light Fader for Automobile. The schema is build using low power operational amplifier LM324 which only need around 3mA of current, so it wont bother the battery supply if left connected for extended periods. This schema is similar to the fading eyes schema above and is used to slowly brighten and fade interior lights of older cars.

The top two op-amps schema module (pins 1,2,3 and 5,6,7) form a triangle wave oscillator running at about 700Hz while the lower op-amp (pins 8,9,10) produces a linear, 5 second ramp, that moves up or down depending on the position of the door switch. The two transistors and associated resistors serve to limit the ramp voltage to slightly more and less than the upper and lower limits of the triangle waveform. These two signals (700 hZ. triangle wave and 5 second ramp) are applied to the inputs of the 4th op-amp (pins 12,13,14) that serves as a voltage comparator and produce a varying duty cycle square wave that controls the IRFZ44 MOSFET and lamp brightness. The 5 second fade time can be adjusted with the 75K resistor connected to the door switch. A larger value will increase the time and a smaller value will speed it up.

When the door switch is closed (car door open) the voltage on pin 8 slowly increase above the negative peaks of the triangle wave producing a short duty cycle output and a dim light. As the ramp moves farther positive, a greater percentage of the triangle wave will be lower than the ramp voltage producing a wider pulse and brighter light. This process continues until the ramp is 100% above the positive peaks of the triangle wave and the output is maximum. When the door switch is open, the reverse action takes place and the lamps slowly fade out.

The MOSFET IRFZ44 shouldnt need a heatsink if the total load is 50 watts or less but the temperature of the MOSFET should be monitored to make sure it doesnt overheat. The on-state resistance is only 0.028 ohms so that 4A of current (48 watts) is only around 100mW. For larger loads, a compact heatsink can be added to keep the MOSFET cool. - Interior Light Fader for Automobile schema diagram

Wednesday, August 27, 2014

Audio Pre Amplifier Wiring diagram Schematic

Simple Audio Pre-Amplifier

This simple schema provides good gain to too audio singnals .
Use it in main of an RF oscillators to make an RF transmitter that is very sensitive to sound

Audio Pre-Amplifier Circuit Diagram

Audio IC TDA1013 4 5W

Circuit diagram IC TDA1013 4.5W:
Audio IC TDA1013 4.5W

How to Build Unregulated Linear Power Supply

Unregulated power supplies contain four basic components: transformer, rectifier, filter capacitor, and a bleeder resistor. This type of power supply, because of Us simpticity, is the least costly and most reliable for low power requirements. The disadvantage is that the output voltage is not constant It will vary with the input voltage and the load current, and the ripple is not suitable for electronic applications. The ripple can be reduced by changing the filter capacitor to an LC (inductor-capacitor) filter but the cost to make this change would make use of the regulated linear power supply a more economical choice.


FM Radio Jammer circuit diagram


This is FM radio jammer schema diagram.This is not legal device in many countries.So dont misuse this.we dont get any response of it.




Note

# This schema operates with 9V

# L1 make 6 turns of 16AWG enamelled copper wire on a 9mm plastic former.


High impedance balance output circuit

Because of high input impedance required to maximize CMRR, High impedance balance output circuit shown in figure below , has been used for the input impedance is determined solely by the input bias resistance R1 and R2. High impedance balance output circuit also useful for interfacing with valve equipment in the strange world of retro-hi-fi.
high
High impedance balance output circuit
Adding the output cathode followers for valve circuits are expensive and consume a lot of extra energy, so that the output is often taken directly from the anode gain-stage, as a result, even loading bridge the so-called 10 k distortion can seriously endanger performance and output swing available from the source equipment.
All balanced phase dealt with until now have their input impedance is determined by value input resistors, etc., and this can not be raised without lowering the noise performance.
High impedance balance output circuit diagrams above shows one answer to this. Input op-amp itself is quite a lot has infi nite
Impedance in terms of audio, so the input impedance is determined by the need to R1, R2 bias non-inverting input. A property of remarkable and very useful from this circuit is that the addition of Rg resistance increased profits, but maintain the balance of the circuit. This confidentiality guration can not be set to weaken for the advantages of an op-amp with feedback on the series can not decreases below unity.

PC Driven LED Display Wiring diagram Schematic

Here is a schema to generate sequentially running light effects using a simple program written in C. The output of the program is taken from the LPT port of a PC and then fed to the interfacing schema for the LED display. The outputs of the interfacing schema are decoded, inverted, and then connected to LEDs through optocouplers.

PC-Driven
 Fig. 1: Interfacing schema for PC-driven LED display

The interfacing schema along with the 25-pin parallel port is shown in Fig. 1. IC1 (74LS138) is a high-speed 1-of-8 decoder/demultiplexer. In the schema, only five outputs (pins 10 through 14) of IC1 are used. These outputs are inverted using  NOT gate IC2 (7404). Optocouplers IC3 through IC7 (MCT2E) are used to prevent the schema from damage in the event of short schema in the load.  Thus the loads comprising LED blocks LB1 through LB5 are isolated from the interfacing schema including the PC. Each LED block contains a number of LEDs connected in series.

The LEDs can be arranged, for instance, to display a sequential running light and fountain pot as shown in Figs 2 and 3. The colour of LED blocks can be green and red alternately.

LED
Fig. 2: LED block arrangement for sequentially running light   

LED
 Fig. 3: LED block arrangement for fountain pot

The program can be compiled and run through Turbo C compiler. In the program, the function outport(p,x) is used, where ‘p’ is the address of the controller port and ‘x’ is the value sent to it. Here, controller port  LPT1 is used, whose base address is 378H. If LPT2 is to be used, the base address must be 278H. When the delay time delay() is increased, the running speed of LEDs decreases and vice versa.

In the schema, 100-ohm fixed resistors R6 through R10 can be replaced with 100-ohm or 200-ohm presets for decreasing and increasing the intensity of LEDs.

The program for LED display is as follows:



This schema costs around Rs 100.


Sourced By: EFY Electronics Author:  R. Karthick

Tuesday, August 26, 2014

Window Flex with 2 8s

Anti Theft Alarm for Vehicles Wiring diagram Schematic

This simple and inexpensive anti-theft schema for vehicles sounds an alarm simulating a police siren whenever someone attempts theft of your vehicle. The alarm sounds continuously for a few seconds even when the intruder switches off the ignition key. The schema uses only a few components and can be easily assembled and installed on a car with negative grounding.

Anti-Theft Alarm for Vehicles Circuit Diagram


Anti-Theft


The schema consists of an SCR-based trigger schema and audio alarm schema. When the ignition key of the vehicle is switched off, base voltage of transistor T1 is low and it remains turned off. When the ignition key is switched on for starting the vehicle, a positive voltage is applied to the base of transistor T1 through diode D1, switch S2, and resistor R1, which slowly charges capacitor C1. As a result, the base voltage of T1 rises. As soon as the biasing voltage crosses cut-in voltage, T1 turns on and SCR fires, giving 12V DC to the alarm schema.

The alarm schema is built around the siren-sound generator ROM UM3561 (IC1). It has a built-in oscillator, whose oscillation depends on resistor R5. Resistor R6 and zener diode ZD1 limit the voltage to IC1 to a safer level of 3.3V. The output from IC1 is fed to a transistor amplifier built around transistors T2 and T3.

The schema gives sufficient time delay to switch on the alarm and to leave the vehicle. The alarm, once triggered, will sound until switch S1 is pressed to switch off the power supply.

Capacitor C2 is provided to sound the alarm even when the intruder switches off the ignition key. When the ignition key is switched off immediately, C2 discharges through R4 and keeps the alarm activated for half a minute. Reset switch S3 can be used to reset the alarm if needed.

The schema can be assembled on a vero board. Use a small heat-sink for transistor T1. Connect point A to the ignition switch terminal that goes to the ignition coil. The hidden switch S1 is used for power on/off and switch S2 enables the schema.

Note. Keep switches S1 and S2 on before leaving the vehicle. And don’t forget to switch off S1 and S2 before starting the vehicle.

The schema costs around Rs 50.



Sourced BY: EFY: Author:  D. Mohan Kumar

12 Volt Battery Guardian Wiring diagram Schematic

Dont get caught with a flat battery; this easy-to-build schema can cut off the power to a 12V fridge or car stereo system if the battery voltages drops below critical level. Electric fridges in vans and 4WDs are a great idea but if you are not careful, they can severely discharge the battery and leave you stranded. Maybe the battery will end up with severe damage as well. The same problem applies if you have a big stereo system and you like to play it without the motor running.


Main features:
  • Cuts power to load (eg, fridge) when battery voltage drops below a preset level.
  • 10A rating.
  • Low power drain.
  • Chirping sound during cut-out.
  • Flashing LED indication during cut-out.
  • Automatically reconnects power when battery recharged.
Operation on 12V is fine when the motor is running and battery charge is maintained but if the fridge is allowed to run for too long when the motor is stopped, it can flatten the battery in a relatively short time. This is where the Battery Guardian comes into play. It monitors the battery voltage and disconnects power to the fridge before the battery becomes too flat to allow the engine to be started again.

Parts layout:



PCB layout:


Circuit diagram:









Source: Silicon Chip 6 May 2002

Tranceiver DC adapter

This DC adaptor provides a regulated 9V source for operating a transceiver in the car .The IC LM317 is mpounting tab is electrically connected to its output pin. so take this into account tour version of the adapter. The LM317T regulator dissipates 2 or 3 Watt in this circuit , so mount it on a 1- x -2 inch piece of 1/8 inch thick alumunium heatsink. Dont forget to give heatsink on the IC LM317.