ghurd controller problem

[JonnyLed]

I'm experimenting with the ghurd controller, set up as a dump control. I did have to make some parts substitutions.

ZM33064 I used MC33064
BSS92 I used ZVP2106A (pin out is different)
R4 (130 ohms) I used 120 ohms
and instead of IRFZ44N I used IRL530's

I made the circuit on perf board and set the trip voltage to 14.2V using a variable bench supply. Now, hooked up a small 12V water pump and set my power supply to a lower voltage and start to slowly increase the voltage. At the trip voltage the yellow led dimly pulses, keep increasing the dial on the power supply and the pulsing gets faster and the pump speed increases, but the voltage stays at around 14.2V. Then still increasing the dial on the power supply the LED stays on solid and the pump gets faster and the voltage jumps up to about 15.5V. With no load the LED switches either on or off, no in between.

Any ideas?

Thanks,
Jon

[ghurd]

You can Not use a motor for a dump load.
Never ever.

The circuit will work, but the fets or motor Will smoke.

And you forgot the flyback diode.
G-

[JonnyLed]

Hi G,

For lack of something else to use for a load for testing is why I'm playing with the pump.  But is the circuit functioning correctly?

Thanks,
Jon

[edit] Couldn't I use something like an old automobile regulator in front of a motor? [/edit]

[ghurd]

It sounds like it is working correctly.  The margin of error will be far higher with substite parts.

A pump is the worst thing I can think of for a dump load.
Even light bulbs would be better.
Motors and light bulbs void the warrenty on decent factory made controllers, and they would be of no use for a dump load anyway.

Automobile regulators are completely different.  They do not work the same way.  They are not suitable for anything but use on a car.
G-