The Master Of Magnetics "Steven Mark"

[argona369]

.

[Jdo300]

Hello Everyone,

I am running into an annoying hitch while I'm doing some testing. I am trying to make a simple switching circuit to pulse my coils with when I realized that I am having trouble getting my MOSFET to work. I wanted to male sure I could get the switching part alone to work so I connected the Gate of the MOSFET to the positive lead from my function generator (which was set on a 4V square wave 0 to 4+), the Source lead was connected to the + terminal of my DC power supply (Set on 14 volts) and the Drain was connected to the - terminal of the battery along with the ground lead from the function generator. To see if the MOSFET was working right I disconnected the lead going to the negative side of the battery and connected the scope leads across the break to measure any changes in voltage. But for some reason the scope shows that the full 14 volts was there even though my function generator was off (and completely disconnected). When I did turn on the function generator, all it did was make a square wave ripple on the output but it didn't switch the MOSFET on or off at all.... I know it is probably something stupid I am doing here but what am I missing?

God Bless,
Jason O

[otto]

Hello Jdo 300,

if it is a n channel MOSFET you have to connect the Gate to your + pole of the function generator, the Drain to + of power supply, and the - from the power supply and the - from the function generator together.

Regards
Otto

[HMM]

or like this with a coil

[Jdo300]

@ Otto & HMM,

Thanks guys for the correction. It never occured to me that I hooked the thing up backwards  . I'll try the test again later today so I can actually move forward, lol

God Bless,
Jason O