So i want to build a device that, when the light level outside gets above a certain level, it trips a Solenoid that closes my window shades.
As far as i can tell, the best way to do this is to use a photoresistor (in series with a potentiometer for adjustability) to trigger the gate on an SCR and allow (rectified) AC to flow through my solenoid. The problem i can't get past, however, is how to turn the SCR off, which i would like to do rather than run 120 volts all the time once the scr is tripped.
The solenoid isn't the important part, the main part is how do i MOMENTARILY allow AC current to flow and automatically turn itself off (to disengage the SCR)?
Am i on the right track? can i use a DC signal from my photocell circuit to trigger an SCR attatched to an AC source?
Any input will be most helpful.
As far as i can tell, the best way to do this is to use a photoresistor (in series with a potentiometer for adjustability) to trigger the gate on an SCR and allow (rectified) AC to flow through my solenoid. The problem i can't get past, however, is how to turn the SCR off, which i would like to do rather than run 120 volts all the time once the scr is tripped.
The solenoid isn't the important part, the main part is how do i MOMENTARILY allow AC current to flow and automatically turn itself off (to disengage the SCR)?
Am i on the right track? can i use a DC signal from my photocell circuit to trigger an SCR attatched to an AC source?
Any input will be most helpful.