Re: The Resurection

Hi Tim & Peter.

> The 5 amp board is resurected.
> in the morning, A steaming pot of hot coffee was pushed in my hand, (much

appreciated after the drive) and much mulling over of the board took place,
over the next six hours it was duly scoped prodded parts replaced,and brought
back to full working order, (miracles do happen)

The component that was causing most of the trouble was the 0R1 Ohmite resistors.
Two of the FETs on each bridge were getting much hotter than expected. The
stepper motors also showed some rather eratic behavior, i.e. when the step
frequency was altered, the motors would step in the reverse direction.
When looking at the gate pulses on the IRFZ34's at the start of each train of HF
pulses, there was one steched pulse. Oh how much easier it would be with a
picture. After replacing the resistors with some vitreous enamel parts - those
little green ones made be Welwyn and others, the problem disapeared.
I am at a loss to explain it - I don't usually play around with high current
chopper drives and big inductors.

> may look for a better quality Mill to CNC retrofit, but nothing to huge,

There might be a small VMC a little larger than my machine coming in soon, I'll
keep my eyes open. ;-)

Regards, Paul