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Can someone who knows electronics look at my questions on the Build Automated Blinds for $15 instructable? Answered

I don't know why my relay is buzzing when I try to reverse the motor.


Are you applying DC to the relay, or AC (or pulsating AC)? If the latter and you haven't incorporated a rectifier and filter capacitor, it will buzz. A relay may also buzz if you have wired it in such a way that it interrupts its own power, of course. That's basically how a traditional mechanical buzzer or bell works.

I checked and you said it was resolved.... is it resolved? Make sure the relay is hooked up in a sort of h-bridge format - so that the 'reverse' button makes the motor run in the opposite direction while held down.