I hope this is in the correct section if not could a moderator please move it to the correct section...
Basically I have a small project I am working on, that I require help with as I need to control the speed of a motor, which I done electronically before, but never one that is pulling 67A off a 12V supply...
I have designed and built the lure machine, ready for dragging a dummy bunny to aid in the training and maintain the fitness level of a bird of prey, but could be used for dog fitness etc...
But I need to slow the speed down electronically, at one point it was clocked at 5,600 RPM before we fitted the pulleys so speed may have been increased further, I am happy with the speed and torque except for when I wish to load the spool in which case it's running too fast and following a snag in the line resulted in the spool flying dangerously fast in my direction...
So I was trying to work out a way to slow the motor down, without having to use a mechanical solution, as that would over complicate the project...
The motor I am using is a Starter motor (part number is 25092D - M35G) - basic specification of motor is 25092D M35G-12V-0.8Kw AMBASSADOR PETROL STARTER MOTOR 1.5 HM PLUS, that is running off a 12V Motor Bike Battery to make it portable, as the unit will be used in the field...
So it's a series wound dc motor, so am I right in thinking that I could use a MOSFET to control the motor speed using a voltage level shifter on the gate. As I believe a MOSFET is not concerned about the size of current passing through it...
This is what I am thinking of:- NTMFS4846: Power MOSFET 30V 100A 3.4 mOhm Single N-Channel SO-8FL
As I have never done any projects before involving a MOSFET before, or very high currents I need as much help and advice as possible as I don't think I should treat it the same as I would a transistor?
Would I also need to incorporate overload and short circuit protection around it, or will it be ok as it is?
Also would I be safer to use more than one MOSFET with the source and drain connected together?
I wish to work on the design so that I can fully understand how to safely control high current applications, I still have the facilities to build and test the unit here, which I prefere instead of buying in something purpose built...
So any help on this would be greatly appreciated...
Basically I have a small project I am working on, that I require help with as I need to control the speed of a motor, which I done electronically before, but never one that is pulling 67A off a 12V supply...
I have designed and built the lure machine, ready for dragging a dummy bunny to aid in the training and maintain the fitness level of a bird of prey, but could be used for dog fitness etc...
But I need to slow the speed down electronically, at one point it was clocked at 5,600 RPM before we fitted the pulleys so speed may have been increased further, I am happy with the speed and torque except for when I wish to load the spool in which case it's running too fast and following a snag in the line resulted in the spool flying dangerously fast in my direction...
So I was trying to work out a way to slow the motor down, without having to use a mechanical solution, as that would over complicate the project...
The motor I am using is a Starter motor (part number is 25092D - M35G) - basic specification of motor is 25092D M35G-12V-0.8Kw AMBASSADOR PETROL STARTER MOTOR 1.5 HM PLUS, that is running off a 12V Motor Bike Battery to make it portable, as the unit will be used in the field...
So it's a series wound dc motor, so am I right in thinking that I could use a MOSFET to control the motor speed using a voltage level shifter on the gate. As I believe a MOSFET is not concerned about the size of current passing through it...
This is what I am thinking of:- NTMFS4846: Power MOSFET 30V 100A 3.4 mOhm Single N-Channel SO-8FL
As I have never done any projects before involving a MOSFET before, or very high currents I need as much help and advice as possible as I don't think I should treat it the same as I would a transistor?
Would I also need to incorporate overload and short circuit protection around it, or will it be ok as it is?
Also would I be safer to use more than one MOSFET with the source and drain connected together?
I wish to work on the design so that I can fully understand how to safely control high current applications, I still have the facilities to build and test the unit here, which I prefere instead of buying in something purpose built...
So any help on this would be greatly appreciated...
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