I thought I would make a PWM to test the Cybex Tread board. That to give it the speed input signal. So searched and decided the to simulate the circuit.
Since like for ever Multisim has been giving me timestep error, I dedicated quite a few investment on to finding out the reason and all paid off. it was the XP SP3 CD that I use created the run around. Any machine with SP3 wil give u a timestep error and will not simulate any Multisim circuit.
Oh well !! that's solved, back to the circuit.
I simulated the circuit in V11 and see the 555's pin3 connection to the fet.
It was not like tht before, but when I hit "RUN" , the 555 model changes to the one u are seeing above.
Is it telling me that I blew my Timer?