I'm kinda a novice at this circuit building. I'm trying to build a circuit to control a drag racing type start tree. I've built the timer delay as a series of cascading lm555 circuits per the third figure down in this link
**broken link removed**
Then I connected the outputs of of the lm555 to relays to drive the lights on the tree (along with some LEDs to see the circuit woking).
The circuit runs on 12VDC and the tree on 120VAC. I hooked the output of the lm555 across the coil of the relay. Then the Normally Open 'throw' of the relay connects the +120V to the light bulb, the -120V is always connected.
I know very liitle about the relays except for what they're suppose to do. The problem I'm having is the relays seem to stick on. Before I put the relays in the circuit worked perfectly lighting up the leds. Now the relays stick closed and it seems to hold the output high. Is there something I'm missing in hooking up the relays?
please help as soon as you can, people are expecting me to have this done on saturday.
Jay W
505/287 Dakota
**broken link removed**
Then I connected the outputs of of the lm555 to relays to drive the lights on the tree (along with some LEDs to see the circuit woking).
The circuit runs on 12VDC and the tree on 120VAC. I hooked the output of the lm555 across the coil of the relay. Then the Normally Open 'throw' of the relay connects the +120V to the light bulb, the -120V is always connected.
I know very liitle about the relays except for what they're suppose to do. The problem I'm having is the relays seem to stick on. Before I put the relays in the circuit worked perfectly lighting up the leds. Now the relays stick closed and it seems to hold the output high. Is there something I'm missing in hooking up the relays?
please help as soon as you can, people are expecting me to have this done on saturday.
Jay W
505/287 Dakota