Alex Lidow: Inventor of the Power MOSFET

Here is a cute circuit:

G to gnd and it goes off.

Tap D to G and it lights half-bright. It will stay that way for days. Easy way to test for gate leakage.

T to G is fun too.

G to

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

I recall your posting that one long ago—it builds up from noise like an ordinary oscillator.

Fun.

Cheers

Phil Hobbs

How about this one: On/Off with the same push button.

Jeroen Belleman

Yes. Dimmer too.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

SPDT, cheating. ;)

John's original one from 2007(*) just used a lowpass RC from drain to ground, with an SPST from the gate to the capacitor. (I found it by searching for "builds up from noise", a phrase I remembered from the original discussion.)

The late great Vlad Vassilievsky memorialized it in ASCII art, which is good because the original ImageShack photo is long gone:

,---/\/\-----+----o LOAD o-- +V | | | |--' | ___ ||<-, +--o o---||--+ _|_ | --- gnd | gnd

Needs the button press to be not too long--if you press and hold, the drain goes to about +2V, depending on the device.

Cheers

Phil Hobbs

(*)"push-push on/off switch"