i have a circuit that controls a dc motor (valeo,24vdc_).

this is independent of another, but when i start the motor i see a 10 volts noise in the 5vdc source....

........how can i eliminate the noise?
........can anybody help me??

 

It's called regenerative feedback. Use .1 microfarad capacitor from motor leads to ground. Recommend using metallized poly caps.

 

Few things you can look into.
Separate DC power supply to the motor
Provide 0.1 uf or whatever that suits your system across armature terminals.
Star grounding, that is all common 0 v wires to be brought to the power supply board and grounded from one point,
Provide 0.1 uf capacitors across + and - ve supplies to 0 v for all IC power pins.
If possible insert a series with the IC power supply pins 22 ohms 1/2 wat resistor.
Shielding and earthing the body of the motor. If your motor wiring uses the body as a conductor, then you have to insulate with other electronic boards.

Hope this helps,
Best regards,
Sekar