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26 inch LG LCD TV - LG26H1DC1 - power board circuit diagram  SMPS Schematic LG 26H1DC1 – LCD TV Click on the schematic to magnify

Used ICs: CXA2040AQ – SDA9489X – DDP3310B – TDA6111Q – TDA7297 – TDA2822- SDA5555 / SDA5521 – MSP3411 – LA7845 – (6174V-6003E Line Output Transformer) Schematic [Click on the Schematics to Magnify]

32 inch LCD TV - Insignia - Horizontal Frequency 31~60 kHz. SMPS, Audio amplifier, Audio processor, Audio output and LVDS schematic LVDS SMPS Power Audio output

While I was home this winter, I saw that the remote for our TV tuner was damaged physically, causing the buttons to not function responsively. Some of them just didn't work. I saw this as an opportunity for a fun couple days' project to build a new remote controller for the tuner. The TV tuner was manufactured by a brand name RealView and, as expected, I couldn't find much detail about it. Thus, I had to reverse engineer the remote. From my previous experience in working with IR remotes, I had a hunch that the IR was most likely modulated at ~38kHz or ~56kHz. For those of you who don't know how this works, I highly recommend going through this website: http://www.sbprojects.com/knowledge/ir/ Thus, I connected a 38kHz IR receiver I had at home (TSOP1738) to an oscilloscope in order to figure out what IR protocol is used by the remote. Upon pressing the 4 key on the remote, I saw the following waveform: Fig. 1: Oscilloscope waveform capture of the received IR signal Note...

This circuit confuses the infra-red receiver in a TV. It produces a constant signal that interferes with the signal from a remote control and prevents the TV detecting a channel-change or any other command. This allows you to watch your own program without anyone changing the channel !!    The circuit is adjusted to produce a 38kHz signal. The IR diode is called an Infra-red transmitting Diode or IR emitter diode to distinguish it from a receiving diode, called an IR receiver or IR receiving diode. (A Photo diode is a receiving diode). TV Remote Control Jammer Circuit diagram : There are so many IR emitters that we cannot put a generic number on the circuit to represent the type of diode. Some types include: CY85G, LD271, CQY37N (45¢), INF3850, INF3880, INF3940 (30¢). The current through the IR LED is limited to 100mA by the inclusion of the two 1N4148 diodes, as these form a constant-current arrangement when combined with the transistor and 5R6 resistor.

Video IF circuit The main function of the video IF is to change the 38.0 MHz IF signal into the CVBS signal which later fed into the sound and video to the chroma. VIF section consists of a series as follows: IF amplifier This section serves to strengthen the signal until the signal level is required. IF amplifier is equipped with AGC (Automatic Gain Controller) which controls the strengthening of the IF amplifier so that a constant amplitude output video. Amplifier frequency range from 32 ~ 60 MHz makes this amplifier suitable for applications multistandar. PLL demodulator and VCO (voltage control oscillator) IF signal is separated with the help of PLL detector. PLL detector produces a phase reference signal with the IF signal carrier and about 60 KHz bandwidth is determined by PLL loopfilter pin 37. Obtained by comparing the frequency demodulation reference signal with the incoming IF signal. Are required reference frequency (38.0 MHz) generated by the VCO. Appropriate VCO frequency...

Sony Trinitron KV20TS50 - Circuit Diagram SMPS Main board Click on the schematics to zoom in