Snip off the three pin TSOP IR from that old passive infra red burglar alarm which is in your draw unused since it activated at random through the night. Now put it in this circuit to replace the three pin switch here. That is all there is to it. Now whenever you tap any TV remote channel button you will see the LED here flicker. It is handy to place by your TV so that you know when to replace your TV remote batteries if the channels won't change (seeing that your LED here does not illuminate). Alternatively you could replace the LED here with a relay and so have an IR switch which activates using your TV remote. Two of the TSOP pins could go directly across your 5V supply (don't use higher V) and the third pin is a high output which flicks over to zero V when an IR beam is detected (or vice versa), so swap the pins around until you find which way works for your particular TSOP. Practise here by flipping the three pin switch just as a TV remote channel button would do with its IR beam.
