Hi everyone!
I am planning to use a PIR sensor as an "entry-detector", that counts how many times have a door been walked through per day. It would consist of a digital counter circuit (4510s and 4511s, nothing special) and a pir sensor that detects the "number of crossings". Problem is, I'd like to use a 12V power supply, but the PIR's output only produces an output signal of 3.3V. I'm planning to use an op-amp (open loop) to amplify that voltage to make the 4510s count (with a 12V supply I'd need at least 6V for a "high" signal and an open loop op-amp would be perfect for that, it even produces higher voltage than needed.) I have never interfaced an op-amp with digital circuits before. What should I look out for, is that possible or advised at all? (I'm pretty much worried about op-amp output and 4510 input impedance differences... should I be?). I would be highly grateful for any ideas!
Thank you in advance!
I am planning to use a PIR sensor as an "entry-detector", that counts how many times have a door been walked through per day. It would consist of a digital counter circuit (4510s and 4511s, nothing special) and a pir sensor that detects the "number of crossings". Problem is, I'd like to use a 12V power supply, but the PIR's output only produces an output signal of 3.3V. I'm planning to use an op-amp (open loop) to amplify that voltage to make the 4510s count (with a 12V supply I'd need at least 6V for a "high" signal and an open loop op-amp would be perfect for that, it even produces higher voltage than needed.) I have never interfaced an op-amp with digital circuits before. What should I look out for, is that possible or advised at all? (I'm pretty much worried about op-amp output and 4510 input impedance differences... should I be?). I would be highly grateful for any ideas!
Thank you in advance!