PIR and LDR Circuit with 555 and LED

188

02:30:00

Circuit to illuminate LED for some duration if light level is low and motion is detected.

Top left pot (into op-amp +) represents LDR, bottom left pot adjusts darkness point, momentary switch represents PIR, second pot (into 555) adjusts illumination duration.

Note 1: I want the circuit to reset the time out if the switch is toggled again, but this doesn't seem to make any difference and it will continue with the existing timeout.

Note 2: adding a monitor after the AND gate shows that there are crazy voltage spikes after momentary switch is triggered. I'm unsure if this is a circuit design issue or a simulation issue.

published 7 months ago

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