doug08

No. It is designed to be placed under a mat, or even buried under grass. Hopefully I don't have to make this into a metal detector.

Hello. I made this circuit below: http://www.diy-electronic-projects.com/p270-Everything-that-moves-ALARM The circuit does not appear to be working properly, and I would like to get it working. To be honest with you, I never heard of a human body detector using eddy currents. The first image shows the pulses on the gate of the mosfet. They appear to be low duty cycle(around 15-20%). The other images show the pulses received by the smaller coil(5"/100T/26ga enamel wire) placed in the center of the 24ga speaker wire/5 foot diameter (5T) TX loop. The circuit can be set, but you cannot get it to trigger unless you actually touch/move the RX coil.The RX signal on the scope is more or less sinusoidal. Operating voltage is around 13.5vdc. Hopefully you can assist me. There is a 1000uF electrolytic capacitor across the power rail. Pins 4/8 on the cmos 555 and pin #14 of the 4093 are connected together to the + rail. Thanks,Doug