boylesg
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I am trying to use this circuit to control my 12V DC engine:
https://i.stack.imgur.com/gv9jz.png
I am using IRD630A as my FET.
According to my multimeter there is a square wave happening with a frequency of about 75Hz and duty cycle varying between 20% and 90%.
However there is not noticeable change in the pitch of speed of the engine.
I suspect the problem is that the FET gate is not discharging between pulses and hence the FET keeps conducting between pulses.
Why? Because at one stage I forgot to put my 555 in the IC holder, connected up my engine and it was running with a floating FET gate. I had to touch the FET gate to GND in order to stop the engine.
So if that is my problem then what do I need to do to make the gate discharge completely between pulses?
https://i.stack.imgur.com/gv9jz.png
I am using IRD630A as my FET.
According to my multimeter there is a square wave happening with a frequency of about 75Hz and duty cycle varying between 20% and 90%.
However there is not noticeable change in the pitch of speed of the engine.
I suspect the problem is that the FET gate is not discharging between pulses and hence the FET keeps conducting between pulses.
Why? Because at one stage I forgot to put my 555 in the IC holder, connected up my engine and it was running with a floating FET gate. I had to touch the FET gate to GND in order to stop the engine.
So if that is my problem then what do I need to do to make the gate discharge completely between pulses?