Electric Roach Motel

Using a PIC for this device provides a lot of useful functionality.

The timing for the power pulse to the inductor is critical to getting the best Zap from your nine volt battery.  The longer the current is on, the higher the voltage.  Once the inductor reaches saturation, however, you are just waisting power.

Some versions of this circuit charged up a capacitor (C1) with multiple pulses.  This allowed the PIC to monitor the high voltage and produce a regulated output.  Here is the current Source File and Hex File.

 

 

Since our setup only does single sided boards inhouse, a 'surface mount' layout was produced to accomodate thru-hole parts.  For instance, the 8 pads for the PIC socket are spread to 0.5 inch to match the 'splayed out' leads from the socket.


In order to consrver power, a zener was used in place of the usual 5 volt regulator. 

This allows doing extra tricks with the sleep mode for extended battery life.

Another variation uses a PIC12F683 with a switchable clock speed.