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Troubleshooting STR IC Regulator Power Supply

Selasa, 10 April 2012 by skemarangkaian


A. Unable to start.
Can be caused by:
  • No start-up voltage supply Vcc or a voltage less than 16V
  • Electrolityc Capacitors supply voltage Vcc filter dry.

  
2. Led indicator blinking
If the supply voltage Vcc examined rocking. This is because the regulator of life and death because OVLO work., Die-protectionist regulators and auto start life over and over. If it is turned off Electrolityc Capacitors  usually still keep the rest of the cargo.
Can be caused by:

  • Electrolityc Capacitors supply voltage Vcc filter on a pin-4 dry. Replace with a value equal to or slightly larger. - triger UVLO
  • input filter capacitor on pin-1 feed dry behind the declining value - triger OLP
  • Rectifier diode of the switching transformer is damaged (sometimes when examined with avo-meter looks like a still good)
  • cause the supply voltage Vcc drops of the switching transformer (UVLO)
  • Part damage or broken lines on the feedback circuit of the voltage regulator through B to photocoupler - triger OVP
  • Electrolityc Capacitors dry filter voltage B - triger OVP
  • One of the output voltage of the switching transformer secondaries there is a short (over load) - triger OLP
  • Soft start capacitor value decreases - triger OLP

3. Noise arising (noise)
Can be caused by:

  • Transformer windings slack.
  • If there are ceramic capacitors - can sometimes cause interference noise due to its characteristic piezoelectrik like crystal resonator. Replace with film capacitors.

4. When the st-by normal stress. But when the power is on the regulator directly off protectionism no voltage on the secondary this part. Electrolityc Capacitors  are still storing charge.
Can be caused by:

  • Sensor OVP small value resistor on pin-2 to the ground so that the value of delayed triger to OLP or OCP.
  • Regulator IC is damaged

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Note: Be careful when the regulator is not working. Because of Electrolityc Capacitors  may still have a charge when turned off.

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Workings of STR IC Regulator Power Supply

by skemarangkaian

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)
Workings of regulator ic STR
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-5's
  
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


read also ->>>> Troubleshooting STR IC Regulator Power Supply

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Power supply with driver TEA1507

by skemarangkaian

Power supply with driver TEA1507 is mostly used by TV branded PHILIPS. Power Supply has an efficiency rate of up to 90% - thus requiring less cooling, as well as stand-by power required is less than 1 watt.


Power Supply with TEA driver is equipped with a variety of surge protector that has a high reliability - not easily damaged if any part of a damaged power supply circuit and power transistor or FET heat is not easily damaged. Power supply circuits are dapatapat working on ac input voltage between 85 up to 275v. The way it works with the driver circuit power supply TEA 1507 is quite simple, so easy tracking of damage to the circuit.

Power supply with driver TEA1507

The picture above is the basic power supply circuit with TEA1507

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How Regulator with 2 Photocoupler

Senin, 09 April 2012 by skemarangkaian

Working of Regulator with 2 Photocoupler that is :
  • Photocoupler N901 - used as a coupling-off control on the regulator by mikrokontrol. Which is set high and low voltage B + (st-by at the B + voltage is low). Control of the pin-37 POWER mikrokontrol → V610 → VD913 V908 → N901.
  • Photocoupler N903 - used to control on-off the regulator of X-ray circuit protector. X-ray protector circuit of flyback → VD451 → VD452 → SCR VS472. If the flyback voltage regulator over the job will automatically be turned off by N903
  • To disable the X-ray circuit protector, it can be temporarily removed photocoupler N903 first. In normal conditions the voltage at the transistor V474 should be zero.

Regulator Schematics with 2 photcoupler
Regulator Schematics
Trobelshuting there is no voltage for 5v st-by on the secondary :

Regulator Schematics 5 V
  1. Disable by removing the first circuit protectors N903
  2. Check the voltage of 300V
  3. Check all transistors
  4. Check the start voltage of 300V by R909 >> R906 to the base of transistor power regulator
  5. Check the feedback C910 >> R904 (to oscillate)

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Different types of TV TUNER

Minggu, 08 April 2012 by skemarangkaian

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
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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Vertical IC PIN-OUT DATA

by skemarangkaian

Vertical Vin = input (non-inverted), Vout = Vertical output, VfB = Vertical feedback (inverted inpput)
Vcc to pump-up can be traced through the diode PUM-up and pump up Elco Capacitor
VfB = or to Vin2
= Gnd or Vcc (-)

Vertical IC PIN-OUT DATA.jpg

Vertical IC PIN-OUT DATA
AN5521 Vin = 4, Vout = 2, Vcc = 7, Gnd = 1, VfB =
AN5522 Vin = 7, Vout = 5, Vcc = 2, Gnd = 4, VfB = 1
AN5539 Vin = 4, Vout = 2, Vcc = 6, Gnd = 1, VfB = 5
AN15525 Vin = 7, Vout = 5, Vcc = 2, Gnd = 4, VfB = 1

LA7832 Vin = 4, Vout +2, Vcc = 6, Gnd = 1, VfB = 5
LA7835 = 2 Vin, Vout = 11, Vcc1 = 1, Vcc2 = 7,
LA7837 = 2 Vin, Vout = 12, Vcc1 = 1, Vcc2 = 8, Gnd = 11, VfB = 7
LA7838 = LA7837
LA7840 Vin = 4, Vout = 2, Vcc = 6, Gnd = 1, VfB = 5
LA7841 = LA7840
LA7845 = LA7840
LA7846 = 5 Vin, Vout = 3, Vcc = 7, Gnd = 2, VfB = 6
LA7848 Vina = 5, VinB = 6, Vout = 3, Vcc (+) = 7, Vcc (-) = 2
LA7876 Vina = 5, VinB = 6 Vcc (+) = 7, Vcc (-) = 2

STV9302 = see AN5522
STV9379 = See AN5522


TA8403 Vin = 4, Vout = 2, Vcc = 6, Vcc = 6,
TA8445 Vin = 2, Vout = 11, Vcc1 = 1 (9v), Vcc2 = 7 (26v), Gnd = 10, 50/60 =

TDA1771 Vin = 3, Vout = 1, Vcc = 9. Gnd = 5
TDA4865 Vin = 6, Vout = 5, Vcc = 1, Gnd = 4, VfB = 2
TDA8175 Vin = 7, Vout = 5, Vcc = 2, VfB = 1
TDA3653 Vin1 = 1, Vin2 = 3, Vcc1 = 9, Vcc2 = 6, Vou = 5, Gnd = 4
TDA8350 Vina = 1, VinB = 2, VoutA = 10, VoutB =, Vcc1 = 3, Vcc2 = 9, Ewin = 12, Ewout = 11
See tda8357 TDA8351 =
See TDA8357 TDA8356 =
TDA8357 Vina = 1, VinB = 2, VoutA = 7, VoutB = 4, Vcc1 = 3 (12v), Vcc2 = 6 (45V), Gnd = 5
TDA8358 Vina = 1, VinB = 2, Vcc1 = 3 (12v), Vcc2 = 9 (25V), VoutA = 4, VoutB = 10, Gnd = 6.7, Ewin = 5, Ewout = 8
TDA9302 = see LA78040

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Vertical IC Configuration

by skemarangkaian

Various kinds of vertical out IC configuration.Ac coupling -connect from the yoke deflection output to a coil connected directly.Dc coupling - connected the output to the coil through a capacitor deflectioan yoke. Electrolityc Capacitors (usually worth 1000u/35v). This configuration requires two kinds of voltage (the voltage mirror plus-minus).Dc input coupling using diffferential - uses 2 input from the driver IC.

Vertical IC Configuration AC Coupling
Vertical IC Configuration AC Coupling

Vertical IC Configuration DC Coupling
Vertical IC Configuration DC Coupling

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Understanding the workings of Vertical Deflection

by skemarangkaian

Vertical deflection parts, serves to provide a sawtooth current to the vertical deflection coil so that horizontal lines are generated by applying localized horizontal deflection from the top of the screen and moves towards the bottom of the screen. Sweeping PAL system has a vertical frequency of 50 Hz and 60 Hz NTSC system. Vertical deflection circuit there are several variation, is in contrast to the horizontal deflection circuit on television almost all the same.
Broadly , the vertical deflection section comprises:
Yoke DEfleksi
Yoke Deflection
  • Vertical oscillator (vertical countdown)
  • Ramp generator
  • Vertical amplifier drive
  • Vertical amplifier-out
  • Pum-up (flyback generator)
  • Feedback circuit
  • Vertical deflection coil

Countdown vertical as the vertical oscillator. Vertical count-down got input from the horizontal frequency count-down and divide in order to obtain the vertical frequency.
In this section there is a circuit called a "vertical window-counter" which serves to automatically adjust the vertical size of the frequency. Without any input video signal, vertical oscillator oscillates at a frequency of approximately 45 to 55Hz free. If then the aircraft received the system PAL video signals, vertical-counter window will lock the vertical oscillator at a frequency of 50Hz. And if a video signal NTSC system will automatically lock the vertical frequency to 60Hz

If for any damage, so the frequency can not be locked, it will cause:
  • Picture rolling up if the frequency is lower
  • Rolling down the picture if the frequency is higher.

Ramp-generator - vertical pulses from the oscillator is a square, ramp-function generator to change the shape of the signal box into a sawtooth shape. Sawtooth signal shape is determined by the value of resistor-capacitor filter contained in this section.

Vertical count-down circuit and the ramp-generator circuit is in common IC. But there are certain circuits where the ramp generator IC is in the vertical-out, ie aircraft using the TA8690 and TA8445.


Vertical amplifier Drive - serves to amplify the signal before it is fed into the vertical vertical-output amplifier. Circuits generally be one with a vertical power amplifier out.


Vertical power-amplifier Out - vertical sawtooth signal is amplified by this section to be able to supply power to the coil current sawtooth vertical deflection. The working principle of the vertical amplifier-out does not vary much with the audio power-amplifier


Pump Up (flyback generator) - applying localized electron beam vertically from the top to the bottom of the screen. To conduct further re-sweeping the electron beam must be returned with a quick way into the top layer. To do this required a strong pulse but only a moment the so-called vertical-retrace pulse, which pulse is required to establish a higher voltage supply on the vertical-out amplifier.

While doing the sweeping-vertical from the top of the screen to the bottom of the screen vertically-out circuit generally requires a voltage supply of about 25V. And at the vertical-retrace or back from the bottom to the top of the screen quickly takes a larger supply voltage of about 50V. Vertical pump-up circuit is in the vertical IC-out and serves to generate a high voltage at the moment-vertical retrace and require external components consisting of a diode and an Elko.

Vertical-drive circuit, pump-up and reinforcing vertical-out is generally a single IC package in the vertical-out.

There are several types of vertical IC-outs that do not use a pump-up circuit. Instead of the vertical-out requires two kinds of supply Vcc, the supply of low voltage and high voltage supply.

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Protectors Circuit on SMPS (power supply)

Sabtu, 07 April 2012 by skemarangkaian


The simplest example SMPS which still uses 3 transistors (C3807, A1015 and power transistors) classic problem that often occurs is: - Problem in the feedback circuit can cause the output voltage B + over so that it can endanger the aircraft as a whole. For example elco erupted, pcb burnt burnt by over-heated, horizontal transistor short.

- Problem on feedback circuits may cause power regulator transistor is damaged due to over current transistor (eg, due to the 47k resistor transistor circuit on the secondary error detector value is delayed).
- If the input ac voltage drops can cause the power regulator transistor is damaged, due to over current transistor If the secondary there is a power transistor short can cause damage over current regulator.
- Protectors are designed to make the SMPS SMPS "reliable will not be damaged" if there are things that go wrong as mentioned above. 

Switching Mode Power Supply protect Circuit
SMPS Circuit

SMPS circuit using IC systems generally are designed with a surge protector, which include:
  • Over voltage protector (OVP)
  • Over current protector (OCP)
  • Over load protector
  • Short circuit protector
  • Over temperature protector

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X-Ray Protector Circuits

by skemarangkaian

A protector system that is applied at the beginning of the television technique, therefore most often found on old aircraft models. If the high voltage anode of the picture tube flyback tranfo exceed the permitted limit, the picture tube can generate x-rays from the anode and shadowmask are bombarded by electrons at high speed. To avoid this problem then mounted x-ray surge protector circuit , which automatically "horizontal section will be turned off" if the high voltage from the flyback over.

X-Ray vertical protect
X-Ray vertical protect

The workings of x-ray protector:

  • High voltage flyback sampled (generally taken from the pin-heater), rectified and is derived using a divider (devider) that uses a resistor-type high-precision resistor. Sample voltage is used to determine whether the condition is normal flyback voltage or over.
  • A "zener diode" as a voltage sensor connected to the sample. In normal conditions the amount of the sample voltage is below the zener voltage of diode so that the condition "off" or is not transparent.
  • Suppose there is a sudden event increased flyback voltage - the voltage will rise above the sample diode voltage value, which causes the diode "on" or voltage through the diode, which would trigger protectionist active work.



Problems that can lead to x-ray active protector works:

  • Damage that causes the power supply voltage B + or incorrect adjustment over
  • Resonant capacitor to the collector of transistor HOT off the decline or solder
  • Tranfo replacement flyback mounted do not match.
  • Damage to one part in the sensor circuit protectors x-ray alone



X-ray Protect Circuit
X-ray Protect Circuit


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TV Protect Circuit Dead or Damaged ?

by skemarangkaian

Television set equipped with a circuit protector, then there are several possibilities that could occur if there is a problem on one of the circuits. Protect circuit horizontal part - When turned on the horizontal plane will live for a while, but then died again. At the time of death when measured on the horizontal driver indicates that no drive signal. If the power jack unplugged then try to turn on again then repeated a similar incident will happen again. But if if the base of the transistor or transistor try to open removable drive signal was viable.

Protect circuit of microcontroll - If checked the voltage at pin microcontrol power on-off control, power control is turned on when the plane going "on" for a while then back "off". If you unplugged the power jack will power "on" again, but briefly and then keep coming back "off". On certain models sometimes die when the aircraft was marked with the blazing LED indicators blink. Protect circuit tube - aircraft can be turned on but a dark raster. 
IC protek protek rusak
Protect IC

Tested voltage raster screen can be raised to normal flame or flame a horizontal line. Protect circuit the power supply - if enabled aircraft B + voltage of power supply there for a while but then lost or drops. Or the power supply voltage drops and there is but little rocking voltage, which is caused due to power supply to the death over and over again and again. There are models of televisions that do not use the protector system at all, there is only one system that uses a surge protector, but there are also some systems which use a surge protector as well. System protectors are made available for specific purposes. Keep track of the damage that led to protect circuit is sometimes difficult, because it always turns itself off the plane before we can make measurements. By getting to know a wide range of system protectors and understand how it works it will help overcome these difficulties.

Various kinds of protectors television system:
  • Protectors x-ray
  • Vertical Protectors
  • Protectors B + over current (OCP)
  • Protectors B + over voltage (OVP)
  • ABL Protectors
  • Supply voltage surge protector (if short or broken)
  • Protectors white balance
  • Protectors circuit power supply (SMPS)

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STV9380 and STV9381 Vertical efficient

by skemarangkaian


STV9380 and STV9381 is a vertical ic-out which very efficient, so it does not require cooling (heat sink) as the vertical ic is generally. This circuit works the same way as most other vertical ic, except at the amplifier end only. Amplifier section works at the end of class D (this is different to the generally vertical ic which working on a class AB). 

STV9380 and STV9381
STV9380 and STV9381
Vertical signal input by the "MODULATOR" changed its form to first become a form of "pulses" box before it is reinforced by the end of the transistor. Here transistor "amplifier end" work as like "switching transistor". Output result is a strengthening of which pulses of the box is then returned into regular shapes such as vertical signal using an LC fillter (capacitor and filter coil) . Requires IC supply voltage (+) 16V and (-) 16V STV9380 is able to produce pulses of the vertical 2.5 APP (Ampere pitch to peak) and STV9381 3 APP.

STV9380 and STV9381 Vertical efficient
STV9380 and STV9381 Vertical efficient

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SAMSUNG protect circuit with LA76931

by skemarangkaian

Following is the protect circuit Samsung TV which use IC LA76931 as basic working the protect circuit. This Protect Circuit LA76891 located at pin-30 whichconnected to the collector of transistor Q902.In normal conditions the voltage at the base of Q902 is "low" and the voltage at pin-30 is "high". For the temporary crippling protect, it can be removed Q902 (or to the emitter-base short).

SAMSUNG protect circuit with LA76931
SAMSUNG protect circuit with LA76931
Sampling circuit protect from:

Vertical Protect. Pulses of the vertical-out rectified by diode D355, so that the base voltage is approximately 0.6V Q904 ,and collector voltage is 0v.
X-ray Protect (option). Sampled using a heater voltage of the circuit as shown below. Normal vltage in x-ray path to the base of Q902 is zero.
Samsung TV Protect Circuit

ABL protect. If there is damage to flyback voltage which can cause a high rise ABL, then protect circuit will actively work.

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How to check TV Flyback

by skemarangkaian

There are actually several kinds of tools that can be used for check whether flybak damaged. But we have a simple way we have always done for ascertain whether flybak damaged or is still good, before replacing the horizontal transistor. All it takes is a light bulb with an added Exciter 100Watt cable connection along approximately 25cm.


The trick determine if flyback damaged or is still good is as follows :
How to check TV Flyback
  1. Break up the relationship between the collector of transistor horizontal flyback-out. By (a) Open collector aspirated by means of the printed board solder, or (b) Remove the jumper cables if any, or (b) Cutting prited path.
  2. Ac volt-meter pairs of horizontal transistor base with a ground out.
  3. Turn on the plane a little while - there must be an ac voltage of about 1v. This is done is for ensure that the horizontal oscillator and driver are working horizontally.
  4. Replace light bulb between the collector of transistor flyback horizontal (light diseri the collector).
  5. Turn on the plane while alternately measured heater voltage, screen (screen VR max).
  6. If no defective flyback voltage means. Usually marked with a light bulb that lights a little brighter.
  7. If the flyback is usually a good heater ac voltage is approximately 1 to 2v, screen voltage around 150v. Usually marked with a light bulb that lights dimmed.
  8. Measurements must be done quickly, because if the plane using circuit protectionism - protectionism will actively work then.
Defective flyback symptoms include:
  • Tr horizontal collapsed immediately replaced by new
  • B + voltage drops

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TV Vertical Protectors

Minggu, 01 April 2012 by skemarangkaian

Vertical Protectors (another term surge protector or Vertical CRT Neck Guard or protector) . If the vertical deflection does not work, then the raster will glow a horizontal line. This can cause the picture tube phosphor layer was destroyed by fire when the aircraft be kept alive in the long term.

There are several types of system protectors, vertical relationships:
  • Protector surge protector is connected with x-ray to the horizontal which will trigger the horizontal oscillator is not working
  • Protectors gets connected to microcontrol that will trigger the "power off" so that the plane will turn off automatically or plane alive but raster becomes dark (brightnes level down).
TV Vertical Protectors
Vertical Protect
The workings of the system-vertical surge protector that can be found there are several kinds:

  • Using sampling pulses from vertical-out IC which is connected to microcontrol . If microcontrol  not receive these pulses the surge protector will work.
  • Using a sampling of the voltage supply Vcc-vertical IC connected to the IC microcontrol  using a diode. In the normal kondidi no voltage on the pin-IC microcontrol  protection. If the supply voltage Vcc or a short break then the voltage on the pin-microcontrol protection will come short to ground through the diode and trigger protection to actively work
  • Using the IC supply current sampling vertical-out that will actively work if the current exceeds supply. As the sensor protector installed here a series resistor and a transistor in the supply line where it works similar to the OCP.
Problems or possibilities that may cause the protector of vertically-active work:
  • Vertical IC-out short (broken)
  • No voltage supply to the vertical IC-out.
  • Vertical lines of the IC pulse-out to any part microcontrol  broken or damaged
  • Vertical deflection section does not work (damage to the IC)


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The damage Horizontal LG TV

Minggu, 11 Maret 2012 by skemarangkaian


Often find LG TV is switched off completely. After checking it Hor short TR / koslet so that all the inverter output voltage drop. Start with the appointment of TR page and check the voltage and turns back to normal. Do not always replace with a new TR because TR surely you will lose because they will surely be broken again, if immediate profits and normal life. After checking on the block capacitor Horizontal out that there was a rather plump and lifted it after it is dry there is no value of the capacitance.


The damage Horizontal LG TV
LG TV
Capacitor is located on the collector TR Hor bypassed to ground which is parallel with the diode. For the slim LG 21 "inch typically use 2kV 183j (18n 2kV) for the black pearl 29" using 103j2kv (10N 2kV). After replacement of capacitor TSB and TR Hor who just started a TV and Direct TV was OK. 've Also found a balck pearl TV LG 29 "wide image conditions and so OSD is only half visible. As usual checks are still in the horizontal section. Initially thought to drive the FET TR Hor damaged and wide after being picked and measured FET turns out they will be still good. And start There seem damaged parts elco 250v1uf which already began to get puffy and after replacement image remains the same.

And start looking again what's so broken, and who seemed to actually see the disease as I get 600V 154J capacitor looks a little plump. C they will begin to lift and measure it with tester tester x100K and was not moving at all a sign of C is dry. They will begin to replace the capacitor, because it does not have the same C 204J 250V only that there had to be replaced eventually with this one. Begin with a TV and the picture was no longer visible widening is normally only about the width of the CM because it is not the same capacitor.

Then enter the service menu by pressing MENU on the panel and press 2 times hold MENU on the remote and add value HOR WIDE to fit the image width and by pressing OK on the remote to save the settings and press AV to exit.

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IC LA78040 schematic for vertical deflection

Jumat, 10 Februari 2012 by skemarangkaian

Synchronization circuit to make the signals useful in the process of scanning of the transmitter and sent to the Vertical and Horizontal. To be able to produce images on the picture tube phosphor surface is the same as what was sent, then the necessary adjustments to correct with ualsan which has decomposed on the sender and receiver on the review must be made ​​again, and this is called synchronization.



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On TV transmitter switching pulses that have made ​​the same frequency as in the reviewing, and by using the switching pulse is then mulapenguilasan point getter on the tube and picture tube can be adjusted simultaneously. 
At the transmitter, each end of the line reviews one pulse is emitted horizontally, and also at each end of the line vertical review (this is called a field review), another pulse is emitted. At the receiver using switching pulses had the time of the beginning (start) review can be arranged horizontally and vertically. Switching pulses are called the horizontal synchronizing signal and vertical synchronization.Vertical SynchronizationA. Vertical in the tv series has the following functionsa) bend / open beams of light (information) to the vertical direction.b) Synchronize files from a transmitter in the form of images with short time.

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Treatment LCD monitor

Jumat, 29 April 2011 by skemarangkaian

Treatment LCD Monitor. At this time computer use familiar and already widely used either for work or entertainment. And of course when talking about computers it will not be far away with a device called a monitor. And today use CRT monitors have started to decrease with the LCD Monitor that despite having a price that is quite expensive but have many advantages than conventional CRT monitors.


Here are a few advantages of LCD monitor is a stylish design, flat screen and a brighter color than convex or crt monitor screen, while also LCD Monitors have many advantages among which have a high resolution so that it can help many people especially those working Visual design field.

There are some special treatment for LCD monitors in this case is for the treatment of LCD monitors, the following are some steps steps:

Use the LCD as needed, Do not use if you do not need so-necessary and do not use it 24 hours nonstop jedanya have no time for any electronic item there during his lifetime (Lifetime). Turn off your LCD monitor when your computer dies, in order to save electricity and also keeps your LCD monitor remain durable.
Use the type that has a grounding electrical power, because it can minimize the damage in the event of lightning strikes. This option is optional.
Perform regular cleaning, at least 2 weeks 1 times, for LCD monitors are always in a state clear of dust and other debris. Remember! to clean it must use a very soft cloth that has spread with a special liquid cleaners LCD monitor. If necessary you can buy special equipment to clean the LCD monitor.
Do not engage in cleanup activities in the state of electricity is still flowing, unplug all cables available on the LCD to avoid things that are not desired. The existence of water coming into the series of LCD monitors will be able to cause fatal damage.
Keep the LCD of the things that contain water such as rain water, drinking water etc.. Because all electronic goods electrical short circuit will occur if water enters into the electronic components.
Keep the LCD of goods containing such magnetic sound system, Persani, HP etc. signals. Because it will be fatal is going to happen Noise or damage which may destroy the layout on the monitor screen.
LCD Save a strategic place and safe from the reach of small children, so that you can not avoid tersenggol LCD or a small toy.
Unplug all cables associated with the computer (including LCD) in the event of rain accompanied by lightning, because lightning can be grabbed via the antenna propagate through the cable TV and electricity.
To protect the screen / LCD screen can use the Screen Protector function prevents dust entry into the LCD and also take care of all sorts of scrapes. Remember to choose the screen protector is not a trace when reopened.
If there is damage to your LCD monitors, LCD submit to the experts. Do not disassemble itself without accompanied by experts in the field of electronics. Module Components including LCD monitors that can be easily damaged. LCD Monitor Service you to the service center to ensure the improvement is good and right.
Good article on the LCD monitor is beneficial treatment.

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Switching Mode Power Supply using STR

Jumat, 15 April 2011 by skemarangkaian

Switching Mode Power Supply using STRSwitching Power supply circuit produces a voltage B + (dc voltage) needed television series taken from the net voltage household. G7 G7A chassis and power supply circuit using cool / cold in which the primary and the secondary power supply electrically separated so that the chassis can be directly connected to another device via an audio video terminal.

switcing power supply schematics
Switching power supply

This power supply circuit is a type SMPS (Switching Mode Power Supply) using mosfet transistor integrated circuit voltage controller in one IC package, namely STR-W6654. This IC will control the duty cycle of time off Vth2 Mosfet transistor to control the output voltage. Besides, the IC is also equipped with a safety circuit against overvoltage (OVP), overcurrent (OCP) and over temperature (TSD) circuit is working on 220V ac voltage with the input ac voltage range of 176V to 260V ac or known by the Wide range Regulators.

How to Work Series

Initial bias voltage dc pin6 IC801 obtained from an ac voltage through D811 and R817, in the beginning of this pin6 high input impedance, or simply need a current of about 100uA, if the voltage has reached the 10V, the IC will mendrive Mosfet transistor into On and transformer will generate stress induction through V1 , R819 and D816 making this pin6 voltage rises to 16V working voltage, and at this point impedance pin6 will shrink or current will increase to 30mA.

Voltage Stabilizer

Stabilizing the output voltage of the circuit is done by regulating the length of time off of the transistor current MOSFETs by using the feedback coupler photo released by the D807. And the D807 is controlled by the IC regulator IC802, IC is working based on the transformer secondary winding S2 (main output). Change IC802 PIN1 perceived stress will be informed on the photo coupler D807 and forwarded to the IC801 for correction.

Safety Over Voltage

In the event of errors / defects in the feedback path, the output voltage will rise out of control, but the series / IC801 has been equipped with a safety overvoltage, where pin6 IC801 can serve as a detection voltage, output voltage rises when the voltage V1 uncontrolled transformer also rises and via the R819, D816 IC801 pin voltage also rose, When the voltage reaches 34V in IC801 oscillator will stop / off switch and voltage pin6 will go down, and when the voltage reaches 7.5 V IC is going back to work and pin6 voltage rises again, if it again reaches 34V IC will die, so planes demikiian will be dead-alive, dead-alive.

Safety Flow / Cost More

The series is able to secure the power supply circuit to the flow or more load by detecting current flowing in the drain-source transistors MOSFETs. By placing a resistor R809, R835, and R811 on pin3 (source) and connected to pin7 (OCP), the more current or voltage drop on this resistor can be directly detected by a safety circuit overcurrent (OCP). In the event of overload or over current IC will stop for pin 6 voltage above 7.5V

Safety Over Temperature

IC STR-W6654 is also equipped with over temperature safety circuit (TSD). If an error occurs in the IC cooling load or metal, can cause uncontrolled temperature rise IC if IC exceeds 140 degrees then it will stop. The aircraft can live again when the voltage is below 7.5V pin6 (main switch is turned off) and the temperature has dropped below 140 degrees.

Stand-By Condition

With working characteristics pin6 tapped IC STR-W6654 especially voltage Latch Circuit Release Voltage (7.5V) the IC can be made to work on a very small load conditions (stand-by)

How it works series Stand-By

In normal conditions PIN1 UOC IC output is 5V (high) and on stand-by condition 0V (low). If the output of PIN1 UOC Low, Q852 off, Q857 is on, thus the input voltage to 10V PIN2 of IC 802 that will cause the output voltage to 52 volts IC801 PIN1. That's due to the influence of input voltage PIN1 decreased from 26 V to 10V. so that the circuit feed back will inform you as there is more current. IC 801 IC801 stop temporarily until voltage falls below 7.5V pin6. After reaching 7.5V IC801 automatically revived. So this event will be repeated with certain intervals. The fall in line with all automatic 90V secondary circuit also fell, including PIN1 (V1) transformer. If the transformer voltage drop V1 also fell tentunnya pin6 IC801, IC801 will follow the working characteristics pin6.

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Audio amplifier with IC AN7522, AN7523 and TDA2616

by skemarangkaian

Audio amplifier with IC AN7522, AN7523 and TDA2616
The series of amplifiers that are used on the television audio, amplifier used amplifier ICs, including the IC:
• AN7523
• AN7522
• TDA2616


Third series of the function with the same system, namely BTL (Bridge Transformer Less). By using such configuration we get several advantages, namely no use coupling capacitors or coupling transformers.


Block diagram of circuit in the IC AN7522, AN7523 and TDA2616 as in the image below :

Schematic AN7522
Schematic AN7522
AN7523 amplifier schematic
AN7523 amplifier schematic

AN7523 amplifier schematic
Schematic TDA2616



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