Hello all.
I just discovered this site and I am really impressed by the great information being exchanged here.
Perhaps someone can help with this:
I would like to build a circuit that, upon power-up, delays a second or two, and then energizes a relay (small reed relay) for approx. 1/2 second, and then de-energizes the relay.
I know I can use a 555 as a one shot, but I'm not sure how to generate the initial delay after power-up.
I used to dabble in electronics all the time as a kid, but it's been many years now. In fact, when I was younger I built a circuit similar to this. When we first got cable TV (1980's!) and our TV did not have a remote control, the cable box came with a remote and would obviously change channels and power the TV on and off. However, the TV always went to channel 2 upon power up. After a couple years, the [3] and [enter] keys on the TV were getting kind of worn out, and it was a huge inconvenience to have to walk up to the TV just to hit the [3] key and the [enter] key. I built a small circuit that fired two relays in sequence and wired them onto the keypad of the TV to hit [3] and [enter] every time the TV was powered up. Of course that TV is long gone and so is my schematic and knowledge of how I did it!
Any ideas?
Thanks!
I just discovered this site and I am really impressed by the great information being exchanged here.
Perhaps someone can help with this:
I would like to build a circuit that, upon power-up, delays a second or two, and then energizes a relay (small reed relay) for approx. 1/2 second, and then de-energizes the relay.
I know I can use a 555 as a one shot, but I'm not sure how to generate the initial delay after power-up.
I used to dabble in electronics all the time as a kid, but it's been many years now. In fact, when I was younger I built a circuit similar to this. When we first got cable TV (1980's!) and our TV did not have a remote control, the cable box came with a remote and would obviously change channels and power the TV on and off. However, the TV always went to channel 2 upon power up. After a couple years, the [3] and [enter] keys on the TV were getting kind of worn out, and it was a huge inconvenience to have to walk up to the TV just to hit the [3] key and the [enter] key. I built a small circuit that fired two relays in sequence and wired them onto the keypad of the TV to hit [3] and [enter] every time the TV was powered up. Of course that TV is long gone and so is my schematic and knowledge of how I did it!
Any ideas?
Thanks!