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Topic: Controling motors with MOSFET (Read 2020 times) previous topic - next topic

boyma

Mar 30, 2012, 08:22 pm Last Edit: Mar 30, 2012, 08:24 pm by boyma Reason: 1
Hello
i need help to make a circuit.

in this scheme i control motor with MOSFET.i have one accumulator.Motor rotates in one side.How can i change rotation of motor?

zoomkat

Quote
How can i change rotation of motor?


H-bridge if you want to change the rotation direction. PWM if you just want to change the rotation speed in one direction.
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boyma


Quote
How can i change rotation of motor?


H-bridge if you want to change the rotation direction. PWM if you just want to change the rotation speed in one direction.

transistor can transmit current from drain to source  and we cant use PWM, no?
can i use this scheme?


CrossRoads

That is the scheme, basically. The Upper MOSFETs are generally P-channel and source current to the motor, while the Lower MOSFETs are N-Channel and sink current from the motor.
You need to use Logic Level MOSFETS and +U must be the same as the Arduino Vcc.
If you want Higher +U, then you need transistors in front of the P-Channels so the gates can go fully high (up to U+) to turn the P-channels off.



You can use PWM.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

boyma


If you want Higher +U, then you need transistors in front of the P-Channels so the gates can go fully high (up to U+) to turn the P-channels off.

i don't understand how we can use transistors in front of the P-Channels.Can you draw scheme, please?

CrossRoads

So basically like this.
When a control line is high, the N-channel MOSFET gate is High and turned on, and the NPN Base is turned on to bring the P-channel gate Low to turn it on.

When a control line is low,  N-channel MOSFET gate is Low and turned off, and the NPN Base is not turned on, allowing the resistor to pull the the P-channel gate High to turn it off.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

zoomkat

Some previous h-bridge projects that might be useful for information.

http://arduino.cc/forum/index.php/topic,53425.0.html
http://arduino.cc/forum/index.php/topic,74454.0.html
Google forum search: Use Google Search box in upper right side of this page.
Why I like my 2005 Rio Yellow Honda S2000  https://www.youtube.com/watch?v=pWjMvrkUqX0

MarkT


So basically like this.
When a control line is high, the N-channel MOSFET gate is High and turned on, and the NPN Base is turned on to bring the P-channel gate Low to turn it on.

When a control line is low,  N-channel MOSFET gate is Low and turned off, and the NPN Base is not turned on, allowing the resistor to pull the the P-channel gate High to turn it off.



You circuit has the p-channel MOSFET's drains connected to the positive supply rail - it should be the sources.
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CrossRoads

Thanks MarkT.  Got it fixed.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

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