RioRand power supply: overcome 2-Ohms minimum load resistance?

[unotre]

I bought a RioRand power supply to run this 12vdc-2.3amp gearmotor (https://www.filastruder.com/products/gearmotor). However, the RioRand requires a load greater than 2 Ohms, otherwise it will blow a fuse, and my gearmotor only measures at .9 Ohms across the windings/terminals. I tried putting a fairly large resistor in line between the PSU and one motor terminal and the resistor burnt up in a split second. Is there a simple way to make this work?


https://www.amazon.com/RioRand-Driv...vernor/dp/B00HUQY9HC/ref=cm_cr_pr_product_top

 

[crutschow]

You can try a 10W, 1 ohm resistor in series with the motor. If that reduces the power of the motor too much then you will need to add an electronic current limiter circuit.

 

[dr pepper]

Welcome to the forum.
You could try a soft start circuit with the motor, it might be just the start up inrush causing the fuse to blow, the only thing is if the load suddenly increased in use the fuse would blow, a curren tlimit circuit as mentioned might do the trick, does the supply you mentioned support current limit?, I see what looks like a current sense resistor on the pcb.

edit: said reisistor is 220r so not current sensing.

 

[unotre]

Thanks a bunch. I'll try the 1ohm resistor first.

The RioRand I got has an external speed controller/pot with it. Since the unit can output up to 48v, and my motor is only 12, wouldn't just ramping up the pot be enough to mitigate the power loss caused by the resistor?

Do you guys think an automotive balance resistor would work? Their resistance is about 1 - 1.3ohms and can handle 40+ watts or so.

 

[dr pepper]

The balast resistor is a good start, note however that power dissipation is probably quoted thinking that the resistor is fastened to a heatsink, ie car body.

Increasing the voltage to compensate for that dropped via the resistor isnt going to work, then you'd be asking the power supply to power the motor as per beforehand and also to power the energy loast in the resistor, worsening not improving things.

Basically using either the resistor or a current limit circuit is effectively lowering the power of the motor to a point that your power supply can handle, the only way to sort the issue out properly is to use a bigger supply.

 

[crutschow]

That ballast resistor should be okay. Give it a try, you won't hurt anything.