control dc motor by linear dc power supplies

[Magnum]

hi, i am doing a project to make a CCTV camera in a robot. The robot is driven by a 48V dc motor. But i find that the PWM control of 48V motor make so much noise to the signal transmission of CCTV cemera, making the images with ripples frequently, although coaxial cable is used to protect the image signals.
So, i want to use constant dc voltage supply to control the motor( i realize the energy will be consumed unefficiently, but energy saving is not the target of this project). Do you have any ideal to control the motor speed and rotational direction by a constant 48VDC power supply?
 

[Soeren]

Hi,

If you're using consumer grade coax cable, the shielding is severely lacking. Either get pro cables (with dual layered tight screening) or even better, make a run of soft copper tubing and put your coax into that, connect shield and tube (let the tube cover all the way) and you should be on your way to interference free transmissions.
Well placed caps on the motors supply wiring will help too (large ceramic caps are the best due to their low ESR and hi frequency "coverage").

[Magnum]

Thank you for your help.
Do you mean i can add capacitor on the motor supply wiring with PWM control? Wiill the PWM be affected by the discharging of capacitors which i add?

[MaltiK]

use a bootstrap capacitor