I've build a very simple circiut with a 12V / 220V relay.
When the relay gets an 12V signal, it triggers the 220V.
Now I want to add an timer to this relay, so when there is an 12V signal, an timer sends a variable signal (3-10s) to the relay.
So everytime the is a 12V signal, the relay will be triggered for some seconds.
Does anyone know how I could make this? and what parts to use ?
The 555 will supply 200mA maximum current for the relay coil. If the relay coil requires more current you will need to add a reaistor and transistor to increase the drive.
Maybe I'm misunderstanding you, or you're misunderstanding "Ground". The "Ground" on the 555 (pin 1) goes to the negative side of the 12v supply. The little upside-down pine tree symbol at the bottom is "Ground", and the negative side of the 12v supply.
Now I got this up and working, but would like to add an little extra feature.
The contact/switch will in my case be a floatswitch.
I would like to make something where I can ensure that if the floatswitch is somehow stuck, I wont keap sending and signal to the relay.
Aka. if the 555 timer gets an on (holding) signal that isen't released again the 555 wil cut of the signal to the relay as it should.
Now it just tricks the relay and keep it on (if I hold the switch on forever)
So maybe the 555 should have an signal there is cut of between the switch and the 555, or can the 55 somehow be set to only trigger once ?