I have connected a SR501 is powered by 5v converted from 12v through 7805 voltage regulator. The output voltage on the signal pin is normally 5v and on high it outputs 8v. This makes my relay module to be always on. Any idea what is happening. The main supply is 12v 2A. Any work around to over come this also will help. Connection diagram below.
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Another thing that i noticed here is, the voltage between VCC and Signal is 3.3v during high signal, the voltage between vcc and signal is 8v