Workings of STR IC Regulator Power Supply

The meaning STR in this article for example is a Sanken regulator series and Fairchild series STR-F/G/W KA05Q Is an ic Quasy Resonant Flyback (QRF) Swiching Regulator comprising (a) control IC and (b) power MOSFETs that are packed into a single unit. The regulator is designed so that only requires a few external components.

How it works :

A. UVLO (under voltage lock out)

Regulators will start working when the voltage Vcc start-up on pin-4 reaches 16V. Once the power supply voltage Vcc further work will be reimbursed through a switching transformer supplied from a diode rectifier. At the time the circuit was working when the voltage Vcc is less than 15V, the regulator controls will still work. regulator will stop working (protectionism) if the supply voltage Vcc drops to less than 11V.

  

2. Feedback control (pin-1)

PWM regulators work using the system, wherein the output voltage B + to stable controlled by the feedback circuit of the output voltage B + >>> >>> photo-coupler pin-1. A capacitor mounted on the pin-1 is used to prevent noise disturbance if anyone does not interfere with the working system.

  

3. Soft start (pin-5)

When the power is turned on first, then the circuit has not been working behind the Uman because there is no output voltage B +. This causes a heavy current on the MOSFET start. To prevent this, the regulator is equipped with soft start circuit internally and an external filter kapasitr.

If the power supply is used to monitor for example, the frequency of the regulator needs to be synchronized. External synchronization signal can be input through pin-5s

  

4. Protectors

Regulators are equipped with all sorts protector.

• Over-current protector (OCP) or Over Load protector (OLP). For example, if there is damage to flyback or def yoke, it will cause the load voltage B + over. If there is such a case the regulator will die protectionism so that IC is not damaged. For over current sensor is a resistor with a small value that is placed on pin-2 to the ground.
• Short protector. If the output voltage B + short, the regulator turns off protectionism.
• Over-voltage protectors (OVP). Regulators are not equipped with a surge protector so if the feedback path disconnected can cause the output voltage of the transformer switching regulator power up or damaged .. With OVP protectionist regulator will die if the voltage supply Vcc pin-4 rise above 22.5v.
• Thermal protector. Regulators will stop working if the temperature reaches 140 degrees Celsius.

6. Auto start.

Regulators will start automatically if the auto turns itself (protectionism) after OVP or OCP

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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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Wiring diagram Schematic of 50W Hi Fi amplifier with TDA7294

The TDA7294 is a Hi-Fi amplifier and can give 100W RMS but with 10% distortion. Supplying 30 Volts you can have 50 Watts RMS with 1% distortion. Frequency range start at 16Hz and can reach 100KHz. Make sure you are using good heatsink. The chip supports mute function as well.

50W Hi-Fi amplifier Circuit Diagram





A symmetrical 30V power supply is all its need to power the unit. 

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Different types of TV TUNER

TV tuner that is used on older models and new models of television there are some differences. Therefore, understanding the different types of tuner would be useful if we want to replace the tuner with the other models.

Supply voltage tuner.

Tuner older models generally use a supply voltage of 12v, the new models are commonly used 5V supply voltage. Some use a 9V voltage, but very rare.

TV TUNER

Voltage Synthesizer tuner (VS tuner)

Tuner that uses a tuning control (VT or BT) with a voltage between 0 to 33V Voltage Synthesizer tuner named. TV can be found on the aircraft models, old and new

Based on how the control band-switch, Tuner VS then there are 2 kinds, namely

Using 3-Band input sw, the VL-VH-U

Using 2-Band input sw, the Band SW1 and SW2 Band. This tuner is actually similar to the type of band 3-sw. For control-sw 2 band is in the tuner will still be converted into 3-sw bands.

Frequency Synthesizer tuner (FS tuner) or the type of PLL

Tuner wherein the tuning voltage and the voltage controlled band switching the digital communication through SDA and SCL. This tuner has a supply voltage Vcc, which is

5V is used for the digital tuner circuit control and

33V (fixed voltage or fixed) is used to control the voltage supplied to the tuning in the digital circuits within the tuner.

(Tuner old) sometimes there are additional circuit voltage of 12V to the tuner.

Frequency band.

Based on the wide range of revenue-frequency band, there are three kinds of tuner

Normal tuner

Superband tuner

Tuner hyperband

Normal tuner, the tuner that can receive broadcasts "on-air" (terrestrial) TV in the frequency band:

• Frequency of VHF Band I - VL 41-68 Mhz
• Band III - VH 174-230 Mhz
• Frequency UHF Band IV - U 470-581 Mhz
• Band V - U 582-960 Mhz
• Band II 87.5 - 104 MHz is used for FM radio broadcasting
• VL and VH bands used for broadcast channels 2 through 12
• U bands used for broadcast channels 21 to 69

Superband Tuner and Hyperband, the tuner can receive broadcast as normal tuner plus the ability to receive broadcasts "off air" CATV (cable television).

• S band using frequency band between VL and VH
• H-band using a frequency band between VH and U
• Superband Tuner can receive the broadcast band S
• Hyperband tuner can receive broadcast band and S band H

Based on the IF frequency out

IF frequency tuner out there who have 38/38.9/45.75 Mhz frequency. In Indonesia generally use 38.9Mhz frequency, but sometimes there is a use 38.0Mhz

Based on the pin-out

There are several kinds of tuner long pin-out configuration. But now almost all the tuner is already using an international standard 11-pin

Universal tuner

China is now producing "universal tuner" 11-pin. Indonesia was just the market we do not know whether it exists or not. This tuner can be used to substitute for the various types of tuners and tuner can adjust to this direct voltage of 5, 9, or 12v.

RF antenna input connector

Form the antenna input connector there are two kinds, namely:

• RCA type connectors
• Antenna RF connector

Tuner modules

Tuner is a tuner module inside there are all Video IF amplifier circuit and the FM-detector. This kind of tuner is using VS and some are using the FS.

Tuner module has output like:

• RF AGC-out
• RF AFC-out
• Audio-out
• Video-out
• Base band out, the signal to be processed into stereo sound circuit.

Except that in tuner is also sometimes diperlengkapa with audio-switch to TV / AV-in. Therefore, to the sound of the AV-in connected via Audio-in found on the tuner module. Sometimes the sound volume to be controlled in the tuner module.

• SONY tuner module 1
• SONY tuner module 2
• Toshiba tuner module

Impedance input / output

Impedance tuner has all kinds of input / output 75 ohm.

How to distinguish 2-band tuners VS sw with PLL tuner FS

In all these circumstances and the removable pin 11 feet was not cut, it is sometimes difficult to distinguish between two band-tuner tuner sw with FS.

Some models have a tuner pin legs partially emptied. FS Tuner has a location pin 30V voltage 3 numbers from the back (of the IF pin out).

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Controller of Solar charger Wiring diagram Schematic

 This is the simple Controller of Solar charger Circuit Diagram .When connecting a solar panel to a rechargeable battery, it is usually necessary to use a charge controller schema to prevent the battery from overcharging. Charge control can be performed with a number of different schema types. Lower power solar systems can use a series analog charge controller. Series regulators control the charging current by interrupting the flow of current from the solar panel to the battery when the battery reaches a preset full voltage. MPPT controllers use an inductor for energy storage and a high frequency switching schema to transfer the energy to the battery.

This schema is for a shunt-mode charge controller. In a shunt-mode schema, the solar panel is permanently connected to the battery via a series diode. When the solar panel charges the battery up to the desired full voltage, the shunt schema connects a resistive load across the battery to absorb the excess power from the solar panel. The main advantage of shunt-mode solar regulation is the lack of a switching transistor in the power path between the solar panel and battery. Switching transistors are non-perfect devices, they waste a percentage of available solar power as heat. Inefficiency in the shunt-mode controller’s switching transistor does not effect charging efficiency, it only turns on when excess power is purposely being wasted.

Controller of Solar charger Circuit Diagram 

Solar power is routed from the PV panel through the 1N5818 Schottky diode to the battery. When the battery reaches the full setpoint, the output on the lower half of the TLC2272 dual op-amp turns on. This activates the IRFD110 MOSFET transistor and connects the 68 ohm 3W load resistor to the battery. The load across the battery causes the battery voltage to drop, and the comparator schema turns back off. This oscillation continues while solar power is available. The 300nF capacitor across the op-amp slows the oscillation frequency down to a few hertz. The two 100K resistors in series provide a regulated 4.5V reference point for use as comparator reference points.

The 2N3906 transistor is wired with a zener diode in its base schema, when the PV voltage is above 12V, the 2N3906 transistor turns on and enables the comparator schema. The upper half of the TLC2272 op-amp inverts the dump load control signal, this is used to power the high intensity red LED. The LED turns on when the battery reaches the full setpoint. The LED does not waste any useful charging power since it only turns on when the battery is full.

The 78L09 IC provides 9V regulated power to the comparator schemary. Operational power for this schema is provided entirely from the PV panel, there is virtually no power taken from the battery at night.

This schema can be modified for higher amperage by replacing the 1N5818 diode, 68 ohm load resistor and IRFD110 MOSFET with higher power components. If the load resistor is connected directly across the PV panel at noon on a sunny day, the PV output voltage should drop to 12V or less. Higher power PV panels will require a resistor with lower ohms and a higher wattage rating. In cold climates, it may be useful to use the load resistor’s heat to keep the battery warm.

Operation of a high power version of this schema with a wind generator should be possible, although the author has not tried this. For a 20 amp version of this schema, the IRFD110 MOSFET should be replaced with an IRFZ44N and the 1N5818 schottky diode should be replaced with a 20L15T. Both of these parts should have large heat sinks. The 68 ohm/3W resistor should be changed to a much larger resistor, An 0.6 ohm/250W resistor would be able to handle 20 amps at 12V.

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