Simple touch sensor ( take 3 )

[seefeldt81]

Simple touch sensor (( take 3 ) Please help I don't know what Im doing)

I've been able to produce a touch sensor with very few parts but instead of being constantly on when you hold your hand on the touch plate it fluctuates off and on rapidly. does anyone have ideas on how to make it so the signal can be constant.

**broken link removed**

 

[KMoffett]

Why did you start a new thread on this?

You might try placing a diode between your touch sensor and the MOSFET's gate (cathode to gate). This changes the AC input signal to pulsing DC. Then place a small capacitor from gate to common. This will smooth out the pulsating DC. You can play with the capacitor's value. Too small and it won't smooth the pulses, too large and it will take a while for the relay to open after you remove your finger.

Ken

 

[Hero999]

You might want to add some ESD protection diodes so the MOSFET doesn't get blown by the tiniest static charge.