PIR to switch a 555 timer

Thread Starter

Speedjayg

Joined Dec 13, 2012
9
Hello i am looking to hook up a PIR Sensor Module to activate a 555 timer kit that i purchased. I plan on using this PIR Sensor (http://openimpulse.com/blog/wp-cont...les/DYP-ME003_PIR_Sensor_Module_Datasheet.pdf) which outputs 3.3V on high on this kit (http://www.velleman.eu/downloads/0/illustrated/illustrated_assembly_manual_k2579.pdf) I would like to use the PIR sensor as the Switch SW1. I was wondering if that would be possible cause the PIR sensor only has a output of 3.3V or if that would work as the trigger. (The Schematics are in both links) Thanks in Advance
 

Dodgydave

Joined Jun 22, 2012
11,277
Use an NPN transistor like a 2n2222 , base to terminal 2 pir pcb, emitter to 0V, collector to pin 2 on the 555 timer, no base drive resistor is needed as there is one already on the pir pcb, make sure the 0v on both pcb's are connected together.
 
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Thread Starter

Speedjayg

Joined Dec 13, 2012
9
Hello thank you for the fast reply. How would you hook those two circuits up together to get them to work properly. Can you show me how to hook these two circuits using the schematics? I plan on using the PIR sensor as Switch SW1 and then the timer will run for 8 seconds.
 
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