OpenSprinkler › Forums › Hardware Questions › OpenSprinkler Pi (OSPi) › Relay board that works with DC solonaid ? › Re: Re: Relay board that works with DC solonaid ?
May 24, 2014 at 7:05 pm #26905
Latching solenoid only draws power when it opens or closes, and does not draw power when it remains in the same state. It’s sometimes called bistable solenoid. Applying a positive voltage opens the solenoid valve, and reversing the polarity closes the valve. The coil on the solenoid typically has very low resistance (a few ohms) so it momentarily draws a high current, often up to a few amps. You are supposed to only apply an impulse voltage instead of continuous voltage, otherwise it can quickly burn the coil or short the power supply.