Critical Components

[garydiy]

Hi Paul,

I have built you Motor decoder but the motor is really noisy and only hisses.
On further investigation I am seeing lots of high frequency noise which is modulating the L272 output.

I have used 1N4001 general purpose diodes for D4 to D7.

Would this cause the problem?

Thanks in advance.

Gary

[Paul Harman]

1N4001 are no good, they are too slow so will probably be getting a bit warm, and will probably be loading up your command station.

That probably will not cause the motor hiss, for that you will have to adjust the PWM frequency with CV9 to match your motor. Reduce the value until you get good torque on the motor.