>> The attached shows one of the H-bridge controllers. >=20 > Presumably the previous PWM outputs were for driving the H bridge ? The HV PWM is for something else. That was just a diagram showing the DC drive for the 4.5V pot motor. Although that drive has been in service for some time without problems, I note your point about catch diodes Joe --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .