- Joined Dec 28, 2015
Hello. This is my first post but not exactly my first rodeo. I have designed a circuit that I want to expand upon, but I am baffled as to why it is working backwards. The comparator works fine, the LED comes on as the temperature rises, I can set the temperature via the potentiometer just fine. Life is good so far. But when I try to add a relay so I can fire the Piezo, I cannot understand why the relay coils are energized when the LED is OFF and de-energized when the LED is ON. I want that part to be the other way around. I am sure it is something simple, but I have been playing with this circuit for days and cannot seem to grasp why it is backwards. Also, the LED is very dim but on a little when it is supposed to be dead off. I am always appreciative of direction and advice, so please do not hesitate to tell me what ELSE this circuit needs to be solid. Thank you!
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