I am experimenting with a k8055 to control a model railway layout. I am using a PWM output to control motor speed, via a MOSFET output stage, and a digital output to control direction of travel, via a change over relay.
All well and good, most of the time! However on occasions the k8055 seems to lock up and I lose all control. The demo program shows “not responding” and closes MS VB6 with it. Then I have to unplug the k8055 to reset it and start again.
I thought I had cured the problem by adding a series diode, and a clamp to ground, on the PWM output (I could see -ve going spikes of 20V here). However the problem persists on occasions. I have not been able to link the problem to anything specific happening at the time. I presume I have some sort of noise problem?
Any suggestions would be greatly appreciated. Many thanks.