help with m7615 and pir sensor re200b

Thread Starter


Joined Jan 17, 2010
Hi to all! I'm a new member here at all about circuits and I have a few questions in mind.

I'm actually a novice when it comes to electronics so forgive my ignorance and stupidity.

I'm actually creating a project shown in this link:

I'm assembling the relay application of the m7615 ic using a re200b sensor and it doesn't actually work. The cds pin I shorted to ground as I have been testing it without cds while the RTI and RTX pins I used 1MΩ for th3 resistor and 0.1μF for the capacitor. I removed the transistor up to the relay and replaced with with an LED to easily see the results. Immediately after connecting 5V to VDD, the LED lights up and doesn't turn off even if there are no human presence after the 20-second warm-up.

Help me please. It would help me understand electronics.