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Topic: motor with own power throw transistor (Read 643 times) previous topic - next topic

boyma

Mar 06, 2012, 09:17 pm Last Edit: Mar 06, 2012, 09:20 pm by boyma Reason: 1
Hello
i want to connect battery with 12V,10A to motor and then control it throw PWM
there is  scheme

i use IRF1018E
Problem:current of motor 3-4A,but it have to be 10A
sorry for my english
and there is some noise which going from motor,why it happens?

retrolefty

Problem is most likely that the MOSFET is not a LOGIC LEVEL MOSFET and the arduino output pin cannot fully turn on the device. While turned on, take a voltage reading between the drain terminal and ground. If it's not zero or just a few millivolts then the device is not turned on fully.


Lefty


MarkT

Always ensure you get a MOSFET that is described as "logic level" in its datasheet - only these can be controlled directly from 5V.

The vast majority of TO220 packaged MOSFETs are NOT logic level...
[ I won't respond to messages, use the forum please ]

boyma

thanks for your answers
can i use FQP30N06L? here he's datasheet http://lib.chipdip.ru/226/DOC000226423.pdf

retrolefty


thanks for your answers
can i use FQP30N06L? here he's datasheet http://lib.chipdip.ru/226/DOC000226423.pdf


Yes, that is a logic level power mosfet.

Lefty

boyma

strange but with this transistor similar problem+he strongly heats

retrolefty

#6
Mar 07, 2012, 09:36 pm Last Edit: Mar 07, 2012, 09:38 pm by retrolefty Reason: 1

strange but with this transistor similar problem+he strongly heats



Measure the drain voltage to ground while under load and state the value you find. Also measure the current flow to the motor and state it's value. Do these measurements while just wiring +5vdc to the gate, not using the pwm signal from the output pin.

Lefty

boyma

#7
Mar 07, 2012, 11:17 pm Last Edit: Mar 07, 2012, 11:20 pm by boyma Reason: 1

if i disconnect 3V ,then I=5A
smth strange

retrolefty



if i disconnect 3V ,then I=5A
smth strange


Ok, you've got it wired wrong. You should wire an N channel mosfet as a 'low side' switch, not a high side as you have. Wire +6 to motor, wire other motor lead to drain, wire 6v negative to source terminal and to negative of 3v supply. Also you should wire a 10k resistor from gate to source terminal to drain off gate capacitance when gate voltage is removed.

Lefty

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