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Unread 23-05-2008, 20:40
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DonRotolo DonRotolo is offline
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Re: Adding Remote Control To A TV

Not as easy as it sounds.

The hard part will be learning exactly how to control power, sound and channel. There probably are switches for these functions, what you'll have to do is open up the TV and get access to those switches, the actual wires or PC Board spots where they contact closures are happening. Run wires from the switches you need to conrtol to a connector (this will make things easier, trust me), and then build a circuit that creates contact closures in parallel with the switches, controlled by IR.

That can be as simple as a microcontroller closing a relay when "signal xxx" is received by IR.

A word of caution: There are dangerous (as in FATAL) voltages present inside a TV, for weeks after the TV was last connected to power. The TV Tube runs at several kilovolts, and is essentially a big capacitor, storing that voltage for a long time. STAY AWAY from the picture tube, the rubber 'suction cup" that insulates the HV wire to the tube, and everything that the HV wire connects to (gegerally a HV transformer called the "flyback transformer" on the circuit board).

ALSO, a TV metal chassis is NOT GROUNDED, but it is HOT, as in it carries LINE VOLTAGE even with the TV set switched off. UNPLUG the TV before touching it. Never power it up unless ALL covers and screws are in place. Ever.

There are other lethal surprises inside a TV, so just be real careful. ALWAYS work with one hand in your pocket - really - as this helps protect against stopping your heart if you do manage to touch something.

Sorry, an old TV engineer here, and have seen guys get very nasty surprises. I once got an HV jolt from a 19" TV that was unplugged for almost a year (!), it knocked me across the room, onto the floor, and my arm was numb for a whole day. Truth.

Don
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