Hello guys,
I have a motor (1,5kw 12v) and I need a controller for this motor, anyone have a schematic to do this? Or any tip to me?
Thank you.
Lucas
Wow that's some serious current you'll need - is this a starter motor?
This motor if from a hydraulic unit that I'm using for a project. I need to control the motor, for after that control the valves that will make my model move!
Would it be sufficient to control it just ON or OFF with relays?
Or do you need speed control?
...R
Hello Robin, no. I need speed control...
At that sort of rating there is a high probability that the motor used series wound field coils which carry the full armature current. It may also have a parallel field coil to control top speed (preventing run-away under zero shaft load)
You first need to establish if it uses field coils or permanent magnets.
If the former, your chance of good speed control is slim since torque and speed are dependant upon motor current.
As the motor was fitted to a hydraulic pump it probably run at a singe fixed speed with very high starting torque, in which case it may well be a series wound motor
Hello jackrae,
I dont think that it has permanent magnets, I know that it's brushed.
This motor not run at a single fixed speed as you told, it can run with regulable speed for choose how much oil will be pumped.
Thank you!
Hydraulic control systems often use fixed speed pumps with fluid bypass regulating valves to control pressure
If motor does not have permanent magnetic pole pieces there is little chance of getting good speed control
DC motors all have brushes (unless they contain an invertor to produce 3 or more phases as in BLDC)
Is there any further information on the data plate
A photo of the motor internals would be helpful
12V is pretty impractical for that power level, forces you to use massive busbars and expensive
contactors... Is the 1.5kW a continuous rating? I suspect not.
On the basis that the motor actually exists, then, if it's suitable for use, it is practical.
You don't need busbars for 100-200 amps, just heavy cable.
For ease of installation, assuming you're still going to use this motor take a look at using welding cable. Fairly cheap, very flexible and easy to work with. However both +ve and -ve lines will need tieing together as, at those sort of currents, they will try and fly apart due to induced magnetic fields. (been there, done it and got the t-shirt to prove it)
jackrae:
Hydraulic control systems often use fixed speed pumps with fluid bypass regulating valves to control pressureA photo of the motor internals would be helpful
If it doesn't have these, it will be subject to locking the motor under full power at zero rpm, when the hydraulic fluid has no place to go.
Paul
jackrae:
You don't need busbars for 100-200 amps, just heavy cable.
No but copper wire that thick is expensive, aluminium strip and rod is cheaper.
About £5 per metre for 25mm sq welding cable