TV Protect Circuit Dead or Damaged

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. 

Protect IC

Tested voltage raster Lcd 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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Automatic TV Lighting Switch

Automatic TV Lighting Switch. The author is the happy owner of a television set with built-in Ambilight lighting in the living room. Unfortunately, the television set in  the bedroom lacks this feature. To make up for this, the author attached a small lamp to the wall to provide background lighting, This makes  watching television a good deal more enjoyable, but it ’s  not the ideal solution. Although the TV set can be  switched off with the remote  control, you still have to get out of bed to switch off the lamp.

Circuit diagram :

Automatic TV Lighting Switch Circuit Diagram

Consequently, the author devised this automatic lighting switch that switches the background light on and off along with the T V set. The entire schema is fitted in series with the mains cable of the TV set, so there’s no need to tinker with the set. It works as follows: R1 senses  the current drawn by the TV  set. It has a maximum value  of 50 mA in standby mode,  rising  to around   500 m A  when  the  set  is  operating. The voltage across R1 is limited by D5 during negative  half- cycles  and  by  D1– D4  during positive half-cycles.  T he  voltage  across  these  four diodes charges capacitor C1 via D6 during positive  half-cycles. This voltage drives the internal LED of solid-state switch TRI1 via R2, which causes the internal triac to conduct and pass the mains voltage to the lamp.   Diode D7 is not absolutely necessary, but  it is recommended because the LED in the  solid-state switch is not especially robust  and cannot handle reverse polarisation. Fuse  F1 protects the solid-state switch against  overloads. T he  value  of  use d  here  (10 Ω)  for  resistor R1 works nicely with an 82-cm (32 inch)  LCD screen.

With smaller sets having lower  power consumption, the value of R1 can be  increased to 22 or 33 Ω, in which case you  should use a 3-watt type. Avoid using an  excessively high resistance, as otherwise TRI1 will switch on when the TV set is in standby mode.  Some TV sets have a half-wave rectifier in the  power supply, which places an unbalanced  load on the AC power outlet. If the set only  draws current on negative half-cycles, the cir-cuit won’t work properly. In countries with  reversible AC power plugs you can correct  the problem by simply reversing the plug. Compared with normal triacs, optically cou-pled solid-state relays have poor resistance  to high switch-on currents (inrush currents).

For this reason, you should be careful with  older-model TV sets with picture tubes (due  to demagnetisation diagram). If the relay fails,  it usually fails shorted, with the result that the TV background light remains on all the time. If you build this schema on a piece of perf-board, you must remove all the copper next  to conductors and components carrying  mains voltage. Use PCB terminal blocks with a spacing of 7.5 mm. This way the separation between the connections on the solder  side will also be 3 mm. If you fit the entire  arrangement as a Class II device, all parts of  the schema at mains potential must have a  separation of at least 6 mm from any metal  enclosure or electrically conductive exterior  parts that can be touched.

Author :Piet Germing - Copyright : Elektor

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Power amplifier compatible with TV audio

In this amplifier circuit using IC TDA8944J as the main amplifier with dual-channel audio amplifier with 2 x 7W output power at 8 Ω impedance. And a minimum supply voltage of 9-18 Volts. In this ic contains two Bridge Tied Load or BTL amplifier.

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