DC motor power supply

[gehan_s]

hi all,

Are there any disadvantages to powering a DC motor using a laptop charger or with any SMPS for that matter?

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.

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

Regards !!!!!!!

 

[audioguru]

A DC motor might not start running if you limit its startup current with a series resistor.

 

[wizard]

Hi,
Why would you think that your DC motor needs to be started by a soft starter?
The value of the resistor should be very small (say maybe less than 1 or 2 ohms depending the input voltage!) so that your motor could start to turn. You can damage the resistir itself if the motor could not turn...

 

[alec_t]

What are the voltage and stall-current specs of the motor?

 

[ronv]

One other problem with running motors with a power supply is that many don't have much capacitance on the output, so if the motor direction is changed while it is spinning it will "pump up" the supply. This may be a problem for other circuits attached to the supply. So make sure the motor is stopped before you reverse it.

 

[kinarfi]

I have seen cool pads for laptops to sit on that have fans in them, so it must be possible