DC motor power supply

[gehan_s]

hi all,

Are there any disadvantages to powering a DC motor using a **broken link removed** or with any SMPS for that matter?

I will also be using it to power a microcontroller (to control the motor).

Regards !!!!!!!

 

[Electro nS]

yes , the current from SMPS usually cannot handle the motor starting and stalling , which cause the smps TO GO INTO DISCONTINOUS mode and the voltage might drop .

maybe this would work if the DC motor is small interms or power with respect to the SMPS. and also note that the motor will cause noise on the dc bus which might affect the micro controller . but if planned and filtered well the circuit will work.

cheers

 

[gehan_s]

Thank you Electro nS !!!!!!!!!

What if I use a soft start method ? I'm thinking of powering the motor through a small value power resistor at the start and then bypass the resistor using a relay.

Thank you

 

[Electro nS]

yes it might work , but i forget to mention the problems of regenrative braking , which might happen when you order the motor to stop , the excess current will do throw the diode which MUST be place the motor in reverse direction and the switching power supply cannot deal with this power . offcourse you can solve this by using an RC , or RCD snubber across the motor instead of the diode alone .
the problem is small is the motor is small (low current 0.5 to 1A) if motor is bigger the current will cause bigger problem.

anyway hope taht helps , try it it is easy and we will learn from your mistake !

cheers