Dark on relay automatic curtain

[freak5261]

I need to use 2 or more 12v-24v relays on this. I was wondering how do i wire it to the curtain. I have no problems with my light detector. It's just a simple project so I won't be using an actual curtain.

 

[nickelflippr]

Here is a circuit I used for a solar sensor. What is not shown are the limit switches to control end travel. The extra OR'd 2N7000 could be used as a manual control for an on-off-on switch. For reversing direction, a h-bridge can be made from two STDP relays, plenty of circuits on the web.

If relay chatter is a problem, more hysteresis can be added to the comparator, and/or a parallel cap on the relay coil, .