Hi guys I think you've heard this one a million times, however when a searched it in the forum I did not quite find what I was looking for.
I have a dc motor from an old school food processor, and I've ran some test and it started running at about 45V dc.
Do you have any suggestions maybe for an amplifier system to boost up the arduino dc output enough to be able to run the motor and control the speed ?
Just use an N channel power FET, make sure it will turn on with 5V on the gate and take the high voltage driving your motor. Then connect the drain of the FET through the motor to your supply with the source to ground.
Deko!
What Mike is saying is you can not run the motor from Arduino directly. You need a seperate power supply, and then the FET hooked up as he suggests.
Hey ppl I used an IRF520 mosfet and I think I connected correctly. I used the same set up as in the arduino notebook for powering larger loads , however i gave Vgs=60V from an external power supply since the motor is larger. When I tested the motor it started running at about 45V.
The thing is the arduino was connected to the gate of the transistor, to open and close the channel. Since the transistor is still working I assume that the arduino was insulated from the 63V supply. However my arduino board seems rewened cause i can't upload anything to it. Can someone tell me from where the 'harmful' signal came from? I powered the arduino from a 9V battery.
i gave Vgs=60V from an external power supply
I hope you meant Vds, Vgs is the voltage from the gate to the source and you can't get that out of an Arduino.
With that sort of voltage I would advise you used opto isolators in the gate, especially if you need more than 5V to turn it on.
where the 'harmful' signal came from?
Probably from the back EMF of the motor. Did you gave reverse polarity diodes across the windings? If not there would be several hundred volts (if not KV) developed across the windings as you turned it off.
Yes I mean Vds as regards to the 60V.
I asked a friend about it and he suggested the problem might be with the power supply which is not a professional one. Most probably the supply gives 1-2A while since the load is quite a large one it requires more than that.
However thanks on commenting on the induced emf. I will make it a point to include these tips in my next project.
Thanks for the help ppl 