DC motor supply

Oct 11, 2021 4 Replies

I have a 24v DC motor that I'm using with a PWM controller supplied by a



24v SMPS. I want to be able to briefly switch the motor to 48v with a relay. I don't have a 48v supply, but I do have a 24v transformer & bridge. I know that the following will give me the 48v, and I think that the Motor Control will be OK with it. But I'd like to know if I'm missing something. The relay will disconnect the Motor Control from the motor before connecting the 48v.

Thanks, Bob



___________________________ +48v _________ | _________ | +|______________|______| Motor |_____ | 24vdc | |Control| | SMPS | | | | -|_______________._____| |_____ Motor |_______| | |_______| | _________ _________ | | 24v |____| Full +|__| |Xformer| | wave | | | |bridge | | |____| -|________________________________ |_______| |_______|


snipped-for-privacy@gmail.com wrote: ===========================

** Bad idea. Doubling the DC input to a brush motor will quickly destroy it - it may last only a few minutes of such abuse. Over voltage creates severe acing across the segments of the commutator.

A good rule is to have no more than 2.5V for each pole of a DC motor.

..... Phil

Your 24V xformer + bridge will give you peaks of over 36 V

Ed

and I think

Phil thanks - I didn't know that. Nevertheless I'm going to proceed with my arrangement:

- it's for my own use & not a customer's, nor a product

- the "briefly" is 5-10 seconds and a duty cycle of maybe 5-10%

- I have a few of these motors and if one is destroyed I'll use another and have learned a lesson

snipped-for-privacy@gmail.com wrote: ===========================

** So you did not want our advice - did you ?

** Did you count how may poles on that motor? It matters just a tiny bit ......

..... Phil

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