Circuit of Simple Temperature Detector

This is an explanation about circuit of simple temperature detector. In many ways, the development of science and technology is getting easier for human activities (especially those who are ready to receive it), the various creations of human creativity in any variety of small things to things that are not small.


create excessive heat detection circuit of an object (could be: water, body temperature, etc.) using a very simple circuit.

This Image of Simplified Circuit Temperature Detector

The circuit consists of:

Temperature sensor (thermistor or the like)
potentiometer 10 K
741 Op Amp
resistor
output: Bi Color Led

Explanation The Circuit

as an automatic switch we use a voltage divider between the thermistor and potentiometer (to set accuracy) and the incoming voltage from the voltage divider had entered the LM 741 op amp and output from the LED will change color automatically.
note: the output can be replaced by buzzer

when heat temperature

when cold temperatures

Thats the circuit of simple temperature detector , this circuit can be used to detect your health, good healthy living ( vida sana ).

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Simple Light Switch

Light switch is a simple circuit that can be used to control the LEDs based on surrounding light. Sensors used to detect the light on this circuit using LDR Light Switches. This circuit uses only three transistors and a few supporting components. As a contactor for Light Switches lamp circuit uses relay. To set the sensitivity of the exposure can be adjusted by adjusting R7. Light Switches circuit uses a source of DC voltage 9-12 Volt. For more details can be viewed directly from the following series of images.

Light Switches Series

Component List:

R LDR

R1 4.7 K

R2 1.2 K

R3 2.2 K

R4 1.2 K

R5 1.2 K

R6 2.7 K

R7 100 K

C1 10 uF/16V

TR1 BC107-BC108

TR2 BC107-BC108

TR3 BC557-BC558

D1 1N4148

RELAY 12V

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Simple 16 Stage Bi Directional LED Sequencer

The bi-directional sequencer uses a 4 bit binary up/down counter (CD4516) and two "1 of 8 line decoders" (74HC138 or 74HCT138) to generate the popular "Night Rider" display. A Schmitt Trigger oscillator provides the clock signal for the counter and the rate can be adjusted with the 500K pot. Two additional Schmitt Trigger inverters are used as a SET/RESET latch to control the counting direction (up or down). Be sure to use the 74HC14 and not the 74HCT14, the 74HCT14 may not work due to the low TTL input trigger level. When the highest count is reached (1111) the low output at pin 7 sets the latch so that the UP/DOWN input to the counter goes low and causes the counter to begin decrementing.

When the lowest count is reached (0000) the latch is reset (high) so that the counter will begin incrementing on the next rising clock edge. The three lowest counter bits (Q0, Q1, Q2) are connected to both decoders in parallel and the highest bit Q3 is used to select the appropriate decoder. The circuit can be used to drive 12 volt/25 watt lamps with the addition of two transistors per lamp as shown below in the section below titled "Interfacing 5 volt CMOS to 12 volt loads"

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Simple 7805 Voltage Regulator Circuit

A voltage regulator is used to produce a constant linear output voltage. It’s generally used with AC to DC power supply. And also it can be used as well as a DC to DC voltage converter . To regulating low voltage, most used device is one single IC. 7805, 7812, 7905 etc. 78xx series are design for positive and 79xx series are for Negative voltage regulator.

7805 is a three terminal +5v voltage regulator IC from 78XX chips family. See 7805 pinout below. LM78XX series are from National Semiconductor. They are linear positive voltage regulator IC; used to produce a fixed linear stable output voltage.  National Semiconductor has also negative voltage regulator chips family, they indicate with LM 79XX. 78xx is used more than 79xx because negative voltage has a few usability purposes as we see.
I was previously posted a 5v regulated power supply circuit using 7805 IC, that circuit and this 7805 voltage regulator circuit is almost the same.

Its output voltage is +5V DC that we need. You can supply any voltage in input; the output voltage will be always regulated +5V. But my recommendation is, don’t supply more than 18V or less than 8V in input. There used two capacitors in this voltage regulator circuit, they aren’t mandatory to use. But it will be best if you use them. They helped to produce a smooth regulated voltage at output. Use electrolyte capacitor instead of ceramic capacitor.

One limitation of 7805 I have found that is its output current 1A maximum. Otherwise it is a good voltage regulator if you are happy with 1A. But if   you need over 400mA current in output then you should use a Heat Sink with IC LM7805. Otherwise it may fall damage for overheating. 

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Simple Automatic Headlight Brightness Switch Circuit Diagram

Going by car the highway with your high-beam headlights can actually increase your visibility, but can be a blinding hazard for other drivers. This easy circuit can be connected into your headlight swap to provide automatic swaping between high and reduced beam headlights when there is oncoming traffic. It does this by feeling the lights of that traffic. In this way, you can propel securely with your high-beams on without blinding other drivers. 

 Automatic Headlight Brightness Switch Circuit Diagram

1. Q1 should me mounted in such a way so it points toward the front of the car with a clear line of site. 
2. Suitable places are on the dashboard, in the front grill, etc.
3. Adjust all the pots for proper response by testing on a deserted road.
4. S1 enables and disables the circuit.B1 is, obviously, in the car already.
5. Before you try to connect this circuit, get a wiring diagram for your car. 
6. Some auto manufacturers do weird things with wiring.
7. Connection A goes to the high beam circuit, B goes to the headlight switch common and C connects to the low beam circuit.
   

Part	Total Qty.	Description	Substitutions
R1	1	5K 1/4W Resistor
R2, R3, R4	3	5K Pot
Q1	1	NPN Phototransistor
Q2	1	2N3906 PNP Transistor
K1	1	Low Current 12V SPST Relay
K2	1	High Current 12V SPDT Relay
S1	1	SPST Switch
B1	1	Car Battery
MISC	1	Case, wire, board, knobs for pots

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Simple Mixer with 4 Input

Here the simple mixer with 4 input and 2 op-amps:

Simple Mixer with 4 Input Circuit diagram :

A basic mixer suitable for mixing microphones or even effects outputs. The overall gain from input to output is one if the pot related towards the input is full up. You can make this a net gain of ten (or any other reasonable gain) by reducing the input resistor towards the second op amp. 10K in this position gives a gain of ten, or 20db. In case you are mixing effects outputs that have an output level control constructed into them, you are able to dispense using the input level controls, or make some have level controls, some not. Audio taper pots are possibly much better, but linear will do the job.

For the op amps, choose a JFET input dual or singles, such as from the National Semi LF3xx series, or something such as the TL072 or TL082.

 

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Simple 600W Audio Amplifier Circuit Diagram

The 600W Audio Amplifier Circuit Diagram is based around {LM4702}manufactured by NATIONAL semiconductors&{MJ11029-MJ11028} by ON semiconductors It is a high fidelity audio power amplifier. Designed for demanding consumer and pro-audio applications. You can also use this circuit with AV receivers, Audiophile power amps, Pro Audio High voltage industrial applications etc Amplifier output power maybe scaled by changing the supply voltage and number of output devices. The circuit includes thermal shutdown circuitry that activates when the die temperature exceeds 150°c. CIRCUIT’s mute function, when activated, mutes the input drive signal and forces the amplifier output to a quiescent state.

 Simple 600W Audio Amplifier Circuit Diagram

Power:
Maximum Output power @ 8ohms : 300watt
Absolute max power supply voltage :±38V to ±40V
Recommended power supply voltage :±30V to ±35V

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Simple Auto Turn Off Battery Charger Circuit Diagram

This Auto Turn-Off Battery Charger Circuit Diagram for series-connected 4-cell AA batteries automatically disconnects from mains to stop charging when the batteries are fully charged. It can be used to charge partially discharged cells as well. The circuit is simple and can be divided into AC-to-DC converter, relay driver and charging sections. In the AC-to-DC converter section, transformer X1 steps down mains 230V AC to 9V AC at 750 mA, which is rectified by a full-wave rectifier comprising diodes D1 through D4 and filtered by capacitor C1. Regulator IC LM317 (IC1) provides the required 12V DC charging voltage.

 Auto Turn-Off Battery Charger Circuit Diagram

When you press switch S1 momentarily, the charger starts operating and the power-on LED1 glows to indicate that the charger is ‘on.’ The relay driver section uses pnp transistors T1, T2 and T3 (each BC558) to energise electromagnetic relay RL1. Relay RL1 is connected to the collector of transistor T1. Transistor T1 is driven by pnp transistor T2, which, in turn, is driven by pnp transistor T3. Resistor R4 (10-ohm, 0.5W) is connected between the emitter and base of transistor T3.

When a current of over 65 mA flows through the 12V line, it causes a voltage drop of about 650 mV across resistor R4 to drive transistor T3 and cut off transistor T2. This, in turn, turns transistor T1 ‘on’ to energise relay RL1.


Now even if the pushbutton is released, mains is still available to the primary of the transformer through its normally open (N/O) contacts.  In the charging section, regulator IC1 is biased to give about 7.35V. Preset VR1 is used for adjusting the bias voltage. Diode D6 connected between the output of IC1 and battery limits the output voltage to about 6.7V, which is used for charging the battery.  Pushing switch S1 latches relay RL1 and the battery cells start charging. As the voltage per cell increases beyond 1.3V, the voltage drop across resistor R4 starts decreasing. When it falls below 650 mV, transistor T3 cuts off to drive transistor T2 and, in turn, cuts off transistor T3.

As a result, relay RL1 de-energises to cut off the charger and red LED1 turns off.  You may determine the charging voltage depending on the NiCd cell specifications by the manufacturer. Here, we’ve set the charging voltage at 7.35V for four 1.5V cells. Nowadays, 700mAH cells are available in the market, which can be charged at 70 mA for 10 hours. The open-circuit voltage is about 1.3V. The shut-off voltage point is determined by charging the four cells fully (at 70 mA for 14 hours). After measuring the output voltage, add the diode drop (about 0.65V) and bias LM317 accordingly.

Author : Y.M. Anandavardhana

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Simple 22W Amplifier for 12V Power Supply Systems

This is a 22-W Amplifier circuit that is designed for or 12-V DC power supply Systems. There are many application for  this circuit,  such as in car audio  application. In car electrical  power supply system, the 12V power supply will be provided by the host vehicle’s battery. 

The capacitor C3 is used to give ripple rejection, since noisy power supply voltage is common in automotive electrical system. The power supply noise signal on car power supply is decoupled by the capacitors C2 and C1.  Smaller capacitor C2 is needed to decouple the high frequency noise, since the larger cap (C1) usually has high equivalent series inductance that prevent the high frequency noise  (such as glitch or spike) to be bypassed. 

The capacitors C5 couple the incoming audio signal to IC1 while decoupling static DC offset. For better bass response, this circuit prevent rolling off of the low audio frequencies by choosing a relatively large capacitance for small signal, 10μF capacitors. Here is the schematic diagram of the  circuit.

 22W Amplifier for 12V Power Supply Systems Circuit Diagram

This circuit prevent power supply pop noise by muting the amplifier at the power-up. The mute input (pin 14) is fed by capacitor C6 and Resistor R1, giving delay on power-up which prevent  turn-on pop. This  R/C time constant gives about 1.4s delay to keep the output muted,  enough to make sure the amplifier reach the stable state after powered up.  

About how this muting works, the amplifier will be ON if pin 14 has at least 8.5 V. The chip will remain in muted condition if the voltage at this pin is below 3.3V.  This input pin need very low current consumption, only about 100 pA for standby (muted)  and around 40 pA when active. The R1 values must be no larger than 100,000  Ω. The R1/C6 constant should be on the second order. If time constant is too short, the turn-on pop will still be heard, but too long  time constant will give unpleasant delay.

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Simple 3 Way Active Crossover Circuit Diagram

This is the Simple 3-Way Active Crossover Circuit Diagram with linear phase response. The problems that exist at common crossover circuit is known. The low pass filter causes a delay in the signal. Unlike the high-pass filter causes a head in the signal passing through it. Thus the frequency separation created some problems such as:

1. Signals of the two filters are mutually exclusive
2. The phase shift between the filter affects the radiation
3. The radiation pattern depends on the frequency

The crossover circuit tries to solve many of the problems mentioned above and based on a study of S. Lipshitz and J.  Vanderkooy, published in the JAES (Journal Audio Engineering Society). A lattice separation uses a linear phase low-pass section with the help of a time delay circuit and a circuit removal gives the output signal with high-pass filter characteristics. The time delay is not constant over the entire frequency range, but changing very slowly and mainly there are phase differences between signals of the two charges, not even close to the crossover.

Simple 3-Way Active Crossover Circuit Diagram

The circuit consists separation as shown in block diagram [Fig.2] two low pass filters of fourth grade, -24db/oct for a line of low-frequency signals and one for the high frequency separation. In the same frequencies operate both units delay time T1 (for low frequency F1) and T2 (for high frequency F2) and give the same phase characteristics of the low pass section.

The delay circuit T1 simulates the time delay introduced by low-frequency filter LPF1, while T2 simulates the time delay introduced by low-frequency filter LPF2 that exists in the line of midrange. Then the signal from the low pass filter removed [IC7A-B] of the signal has been delayed, a clear signal that the characteristics are the same as a signal that has passed through a high pass filter. At the exit of each line is a trimmer with which we can adjust the level between the levels of loudspeakers. The power circuit is a well-stabilized voltage + /-15V. The use of meshed split fourth order Linkwitz forcing crossovers be located at-6db [Fig.3].

The above picture shows the main circuits and the necessary formulas for calculating the low pass filters as well as trusses time delay. There is also an example calculation for crossovers and 200IZ 3KIZ that will help calculate and adjust to your needs. The circuit derived from a relevant article of the magazine Elektor. 

Components List:
R1,16 = 100Kohms
R2,3,4,5 = 56Kohms
R6,27 = 37.5Kohms[33K+4.7K]
R8,9,12,13,14 = 10Kohms
R10,28 = 75Kohms (150K//150K)
R11,29 = NC
R15 = 56.3Kohms
R17 = 12Kohms
R18,19,20,21,22 = 10Kohms
R23,24,25,26 = 37.5Kohms [33K+4.7K]
R30,31,32,33,34,35,36 = 10Kohms
R37,38,39,40,41,41 = 10Kohms
R42,43,44 = 47Kohms
R45,46 = 47 ohms
TR1,2,3,4 = 47Kohms trimmer or pot.
C1,34,35 = 2.2uF 100V MKT
C2,3,7,8,14,15,18 = 47nF 100V MKT
C4,5,6,9,10,11,16,17 = 10nF 100V MKT
C12,13,20,21,22 = 1nF 100V MKT
C19,23,24,30,31,32,33 = 47nF 100V MKT
C25,26,27,28,29 = 1nF 100V MKT
C36,37 = 1uF 100V MKT
C38,39 = 47uF 25V
IC1 = TL071
IC2,3,4,5,6,7 = TL072,NE5532
All the resistors is 1/4W 1% metal film

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Simple Tone Booster Schematic Diagram

This is the tone booster schematic diagram which is published on Everyday Electronics, September 1978 edition. The peaks of frequencies is at 5000 Hz for a “cleaner and more penetrating” sound. The Q1 type is ztx384, while the Q2 is BC415p.

 Simple Tone Booster Schematic Diagram

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Simple Analogue Electronic Key

This circuit uses two comparator that are combined in what is called a window comparator, i.e. resistors R2, R5, and R10 determine a voltage window within which the voltage applied to the junction of D2 and D6 must lie in order for the outputs of IC2.A and IC2.B to both be high at the same time. Given the value used for these resistors, this window is from 10/21 to 11/21 of the comparator supply rail (5 V). If IC2.A and IC2.B outputs are both high at the same time, transistor T1 is saturated via the AND gate formed by D3 and D4, and relay RE1 is energized to operate the electric latch or any other locking device.

Analogue Electronic Key Circuit Diagram

The key is defined by the generation of the specif ic voltage at the junction of D2 and D6, formed, for example, by a simple stereo jack containing the two resistors R4 and R8. Together with R1 and R9, they form a potential divider that needs to be suitably calculated in conjunction with the values of R2, R5, and R10 so that the key can open the lock. Clearly, all this will only work correctly is the supply voltage to these two dividers is stable, which is ensured by IC1, regulating it to 5 V.If we had set the values for R1 and R9, all the readers of this edition of Elektor would have had the same key, which is clearly not a good idea! So you need to decide for yourself not only R4 and R8, which form the key, but also R1 and R9 which let you customize the ‘lock’.1 Here are the relationships between the values of resistors R1, R4, R8, and R9 for the key to be able to open the lock:

10 · R8 · R9 <11 · (r1 + r4) · (r8 + r9) 10 · (r1 + r4) · (r8 + r9) <11 · r8 · r9

 Given the size of the window for me d by R2, R5, and R10, 5 % tolerance resistors are adequate.

Note too that, as the relationships consist of inequalities, and that there are only two (un)equations for four unknowns, this leaves quite a wide choice for the resistor values. We advise you to set at least two of them to preferred values, which will then let you work out the others. If, as is more than likely, this does not result in other preferred values, you’ll then need to use series/parallel combinations to obtain the calculated values or else choose different starting values in order to arrive at a better compromise.

Simple Guitar Synthesizer Circuit

This circuit uses a CMOS Phase Locked Loop, the 4046, to produce a very unusual sound from a guitar, which sounds something like a synthesizer.
The signal from the guitar is amplified by two of the amplifiers in `the 4007. The amplified signal is used by the phase comparator to lock the VCO to the frequency of the mi note played. The VCO does not oscillate until a note is played, when using the low pass filter shown (i.e. the T5 k resistor and 100 n capacitor). lf the value of the resistor is increased, the VCO oscillates continuously at about 1 kHz (with no input signal). This gives very smooth note changes. The basic frequency may he changed by varying the 100 k resistor. 

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Simple UPS Power Supply

This circuit is a simple form of the commercial UPS, the circuit provides a constant regulated 5 Volt output and an unregulated 12 Volt supply. In the event of electrical supply line failure the battery takes over, with no spikes on the regulated supply.

  

Notes: This circuit can be adapted for other regulated and unregulated voltages by using different regulators and batteries. For a 15 Volt regulated supply use two 12 Volt batteries in series and a 7815 regulator. There is a lot of flexibility in this circuit. TR1 has a primary matched to the local electrical supply which is 240 Volts in the UK. The secondary winding should be rated at least 12 Volts at 2 amp, but can be higher, for example 15 Volts. FS1 is a slow blow type and protects against short circuits on the output, or indeed a faulty cell in a rechargeable battery. LED 1 will light ONLY when the electricity supply is present, with a power failure the LED will go out and output voltage is maintained by the battery. The circuit below simulates a working circuit with mains power applied: Note that in all cases the 5 Volt regulated supply is maintained constantly, whilst the unregulated supply will vary a few volts. Standby Capacity

The ability to maintain the regulated supply with no electrical supply depends on the load taken from the UPS and also the Ampere hour capacity of the battery. If you were using a 7A/h 12 Volt battery and load from the 5 Volt regulator was 0.5 Amp (and no load from the unregulated supply) then the regulated supply would be maintained for around 14 hours. Greater A/h capacity batteries would provide a longer standby time, and vice versa.

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Simple 5 Zone alarm Wiring diagram Schematic

This is a complete alarm system with 5 independent zone ssuitable for a small office or home environment. It uses just 3CM IC`s and features a timed entry / exit zone, 4 immediate zones and a panic button. There are indicators for each zone a“system armed” indicator. The schematic is as follows:

5 Zone alarm Circuit Diagram

Circuit Notes:

Each zone uses a normally closed contact. These can be micro switches or standard alarm contacts (usually reed switches).Suitable switches can be bought from alarm shops and concealed indoor frames, or window ledges.Zone 1 is a timed zone which must be used as the entry andexit point of the building. Zones 2 – 5 are immediate zones,which will trigger the alarm with no delay. Some RF immunity isprovided for long wiring runs by the input capacitors, C1-C5. C7and R14 also form a transient suppresser. The key switch acts asthe Set/Unset and Reset switch. For good security thisshould be the metal type with a key.

Operation:

At switch on, C6 will charge via R11, this acts as the exitdelay and is set to around 30 seconds. This can be altered byvarying either C6 or R11. Once the timing period has elapsed,LED6 will light, meaning the system is armed. LED6 may be mountedexternally (at the bell box for example) and providesvisual indication that the system has set. Once set any contactthat opens will trigger the alarm, including Zone 1. To preventtriggering the alarm on entry to the building, the concealedre-entry switch must be operated. This will discharge C6 andstart the entry timer. The re-entry switch could be a concealedreed switch, located anywhere in a door frame, but invisibleto the eye. The panic switch, when pressed, will trigger thealarm when set. Relay contacts RLA1 provide the latch, RLA2operate the siren or buzzer.

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Simple Radiator Temperature Iindicator

This radiator temperature indicator can be designed using electronic schema diagram bellow .Temperature indicator consists of two special zener diode, D1 and D2, connected in series to ensure accuracy of 5.96 V Zener voltage at 25 ° C. As long as the radiator temperature not exceeding 50 ° C, thermal indicator will flash a green LED, one orange will be provided for temperatures of 50 ... 75 ° C and a red LED, for temperatures above 75 ° C.

Simple Radiator Temperature Iindicator  Circuit Diagram

Zener voltage will increase by 20 mV for each temperature increase of a degree Celsius temperature. Radiator temperature corresponding voltage level is compared with two reference voltages, IC1 and IC2 using. When the temperature reaches 50 ° C, IC2s output goes to logic state "1" so that T3 leads and following ignition with diode D4. At 75 ° C, IC1s output is in logic state "1" and, therefore, T2 and T3 will, so that D3 and D4 lights are off. 

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Simple 13 Color LED Rainbow Wiring diagram Schematic

Only a few years ago, the choice of LEDs was limited to IR, red, yellow, and green. The LED manufacturers have been busy extending the spectrum, and filling in the gaps. The latest generation of organic LEDs (OLEDs) has added some dazzling new colors to the spectrum. This schema uses a set of 13 differently colored LEDs to generate a full color spectrum. The photo does not fully represent the colors generated due to camera limitations. The real-world display is very eye-catching. If you want to "trick out" your PC, this schema is for you. Forget about those boring blue PC light displays.

Simple 13 Color LED Rainbow Circuit Diagram

Specifications:

• Operating Voltage: 6-12V DC
• Operating Current: 145ma at 12V DC

Theory:

The LM2940T-5.0 low dropout voltage regulator converts the 6-12V DC input power to regulated 5 Volts. It was chosen over a standard 7805 regulator so that the schema could maintain regulation while operating on a 6V battery. The 1N4001 diode protects the schema from reverse polarity, if a battery or power supply capable of generating over 1 amp is used, a 1 amp fuse should be installed between the supply and the schema. The 5 Volts is used to drive each of the LEDs through individual current limiting resistors.

The resistor values were determined experimentally for equal brightness. Values are given as examples only, different sources of LEDs will require different resistor values. Resistor selection turns out to be the most difficult part of the diagram construction. A 100 ohm resistor in series with a 1K pot could be used in place of each resistor if individual brightness adjustments are desired. The table below lists the LED colors and wavelengths.

LED Color Wavelength Description

Deep Red 700nm ---------

Red 660nm traditional red

Orange Red 635nm "high efficiency" red

Orange 623nm also called red orange

Amber 594nm ---------

Yellow 588nm & traditional yellow

Yellow Green 567nm traditional green

True Green 523mn --------

Cyan 501nm verde green, blue green

Aqua 495?nm ---------

Deep Blue 470nm ultra blue

Powder Blue 430nm first generation "powder blue"

Violet 410nm ---------

Construction:

The schema was built on a prototype perforated board with printed solder pads. The schemary is hand-wired on the back side of the board. Care should be taken when soldering to the LEDs, a clip-on heat sink should be used while soldering the leads. Care should be taken to avoid zapping the LEDs on the violet side of the spectrum, they are sensitive to static electricity. The schema board can be mounted on a piece of white hardboard, the white paint reflects the colors nicely.

Use:

Apply power to the schema and enjoy the colorful glow. Do not stare directly into the array at close range for extended periods, some of the LEDs are extremely bright.

Taking The Circuit Further:

The spectrum could be extended on both the IR and UV sides. A brief scan through the Mouser catalog indicates the availability of these IR wavelengths: 940nm 880nm, 875nm, 870nm, 850nm. UV LEDs at 400nm, 395nm and 380nm are also available. There are also many LED colors available with wavelengths between the 13 colors shown, the colors selected were chosen for an evenly spaced color spectrum.

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Simple Fire Alarm

Here is a simple schema which can be used as a Fire Alarm. 3 Volt is enough to operate. There is not much to the schema. The IC UM66 is connected to its supply and its output fed to a transistor for amplification.

Circuit diagram :

Simple Fire Alarm Circuit Diagram

UM66 is a complete miniature tone generator with a ROM of 64 notes, oscillator and a preamplifier. For amplification we have used a NPN transistor which is BC548. Here BC548 makes a common emitter schema. For limiting the base current we have used a resistance of 220 Ohms so that transistor will not get damaged even if IC is wrong connected.

For heat sensor we have used tube light starter in place of manual switch. In a starter there is a metal plate and a pin with small gap. When starter gets heated then metal plate of starter expands and get in contact with the pin and schema is completed and we get audio from speaker. For fast sensing we can use starter without its glass body by carefully breaking glass cover.

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Build a Simple Quiz Master Wiring diagram Schematic

How to Build a  Simple Quiz Master Circuit Diagram, Quiz master is a device which uses electronics to decide who pushes their button first, Up to eight players each have their own answer button to press, corresponding to the four Red Team and four Green Team LEDs on the master control board. As soon as the first contestant who thinks that he knows the answer presses the button, a loud tone sounds, all other contestants are locked out, and the contestant`s indicator LED lights on the control board so that it`s obvious who buzzed in first. 

The control board also features two selectable time out periods each adjustable from 3 to 15 seconds, setting specified time intervals in which the player must answer before the time`s up! tone sounds. Eight SCRs form the heart of the schema. The anode of each SCR has a positive (+) bias on it by way of an LED and a negative (-) bias on cach cathode. As soon as a contestant depresses his or her switch button (S4 through Sll), a positive bias is applied to the respective SCR gate. 

Simple Quiz Master Circuit Diagram

That bias latches the contestant`s SCR on, which in turn lights up the appropriate LED on the master control board. At the same time, the activity of the SCR latching on turns on the answer buzzer (BZ) and locks out all other contestants. The lockout occurs because relay K2 contacts operate to remove the availability of a bias voltage to the gate of the other SCRs. The other schemary consists of a timer schema and a time`s-up tone-generating schema. 

The timer schema consists of transistor Ql, capacitor CI, resistors Rl through R3, and trimmer resistors PI and P2, Depending on the adjustment of the trimmer resistors and selection switch S3, a specific time period can be set. The lime`s-up tone-generating schema is made up of IC1, transistors Q2 and Q3, and the associated resistors and capacitors. The on time of the tone can be set by P3. Relay Kl, which is operated by the timer schema, serves to reset the entire unit for the next question.

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Simple Bilateral Current Source Wiring diagram Schematic

The Simple Bilateral Current Source Circuit Diagram will produce the current relationship to within 2% using 1% values for Rl through R5. This includes variations in Rl from 100 ohm to 2000 ohm. The use of large resistors for Rl through R4 minimizes the error due to Rl variations. The large resistors are possible because of the excellent input bias current performance of the OP-08,.

Simple Bilateral Current Source Circuit Diagram

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