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Topic: Need to help with circuit adapts to 5-48V drive DC motor design (Read 855 times) previous topic - next topic

kmimax

Need to design a circuit that uses Arduino to control a 5-48V DC motor. Is the circuit shown feasible?

Paul__B


Sorry, that circuit is complete nonsense.  Try again.

(The motor should be between the drain of the FET and the supply, and there should be a reverse protection diode across it.  What do you imagine the Zener and Schottky diodes and Q1 do?)

raschemmel

Quote
The motor should be between the drain of the FET and the supply, and there should be a reverse protection diode across it.  
My thoughts exactly. I don't see how that fet could control the motor. It's not in the same current loop as the motor so all it can do is divert current  , which accomplishes nothing because it doesn't affect motor current.


Quote
What do you imagine the Zener and Schottky diodes and Q1 do?  
A bit presumptuous of you to assume he knows what a Schottky diode is based on the fact he posted that
schematic , don't you think ?

@OP,
Here's a couple of examples of how it's done (high side switching with a P-channel mosfet and low-side switching with an N-channel mosfet so if you only have one or the other you can still make it work.
Driving motor with mosfet
FYI, the mosfets have to be rated for the full motor current.


I like this animation...
Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

kmimax

Thanks for everybody, I am sorry, the circuit is wrong, now change....

raschemmel

Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

kmimax

Have you tried driving it with a PWM pin ?
Is there a problem?Please forgive me, I am a beginner in circuit design. I hope to use PWM to drive. I have tried many circuits and failed because I need to drive high voltage and  current.So far there is no one suitable for 5~48V circuit.

raschemmel

Have you built that circuit yet ?
Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

Paul__B

Thanks for everybody, I am sorry, the circuit is wrong, now change....


Have built that circuit yet ?
Subtle comment that.  :smiley-lol:  :smiley-lol:

Clearly that circuit is but a modest improvement.  :smiley-roll:

May I ask from where you are getting these apparently random circuits?  :smiley-eek:

raschemmel

Correction:

"Have you built that circuit yet ?"
(I'm not going to tell him all he needs is the
mosfet and flyback diode.

I'll let someone else do that...
Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

kmimax


raschemmel

Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

HellasT

Correction:

"Have you built that circuit yet ?"
(I'm not going to tell him all he needs is the
mosfet and flyback diode.

I'll let someone else do that...
I was also wondering why not use only the mosfet and diode and maybe a resistor from gate to ground just to be on the safe side. Specially if you use a logic gate mosfet like the IRL540 yes ?

Paul__B

Tried such a circuit

And that circuit looks correct, except that it will only function (reliably) with a minimum supply voltage of 15 V.

If you want it to operate on less than that, you do need different components.

raschemmel

I would use one of these because it is logic level and N-channel.
Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

kmimax


And that circuit looks correct, except that it will only function (reliably) with a minimum supply voltage of 15 V.

If you want it to operate on less than that, you do need different components.
If it is 5~48V, just choose a high voltage MOSFET?

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