Adding Remote Control To A TV

[Al Skierkiewicz]

Kevin,
There are so many different designs for TV it is hard to give a rule of thumb on anything. How old is the set? Who made it? It is possible that the manufacturer made several models using the same circuit board and chassis. You may only need to poplulate the parts on the board for it all to work.
The picture above is a TV using a "turret" tuner. Those were easy to remote with a motor driving the tuner and a series of relays stepping through an attenuator for sound. The remote control shown in the picture above was available in some sets as an after market option your TV shop could install. FM stereo decoders were also available this way in the early days of FM radio. TVs in the past 20 years have used electronically selected tuners of various types. Some were digital and some analog and all of them hard to interface to in the set.

As Don and Ed have stated, TVs can be hazardous. You can pretty much expect a color picture tube to have 25,000 volts or more in operation. B/W at least 9000 or more. The high voltage design uses the low leakage glass of the picture tube as part of a power supply filter capacitor. The low leakage allows the set to hold that charge for years under certain conditions. Manufacturers also found that line operated power supplies (those without transformers) could significantly reduce not only the manufacturing costs but shipping as well, by removing the transformer. These sets are known as "hot chassis" since one side of the power line wiring is connected directly to the chassis or circuit board ground. That places 120 VAC (RMS) on exposed metal with the covers removed. The primary power used in these sets is then the full wave rectified power line voltage or about 165 volts. It is best to get some experienced help to show how to work with these hazards before attempting it yourself.