chrisg3103
Member
- Messages
- 785
Evening all, have a HF problem and could do with some advice
Bought an ancient BOC tig knowing the HF had died but cant get to the bottom of it, here is what i have so far, first off the scematic (after extensive cleaning up
)
HF is on the far right, pretty simple circuit.
the transformer has been replaced at some point, the mounting holes on the board dont line up with the current one. This is it
manual says HF is 3000v it says 3500v 50ma, close enough?
HF capacitor
so far i have removed, cleaned and reset the spark gap points, 6 tho so set to 0.15mm
replaced an exploded capacitor, but is part of the arc start circuit and has no bearing on the actual HF. Just the bit that turns off the HF once an arc is established
removed and cleaned both rheostats, intensity one needed repaired as cables were atacted to both ends rather than using the centre wiper, was running as a 5 ohm resistor. Now functioning correctly
checked transformer is getting power, 88v with phase shift at min and 218v at max. also checked transformer windings, 10 ohm primary 3k ohm secondary
Checked inductance coil, all good
checked relays, all working as should be
the only thing i cant check is the transformer output and if the HF capacitor is working, would a duff capacitor cause the HF to die? and thoughts appreciated!
Bought an ancient BOC tig knowing the HF had died but cant get to the bottom of it, here is what i have so far, first off the scematic (after extensive cleaning up
)
HF is on the far right, pretty simple circuit.
the transformer has been replaced at some point, the mounting holes on the board dont line up with the current one. This is it
manual says HF is 3000v it says 3500v 50ma, close enough?
HF capacitor
so far i have removed, cleaned and reset the spark gap points, 6 tho so set to 0.15mm
replaced an exploded capacitor, but is part of the arc start circuit and has no bearing on the actual HF. Just the bit that turns off the HF once an arc is established
removed and cleaned both rheostats, intensity one needed repaired as cables were atacted to both ends rather than using the centre wiper, was running as a 5 ohm resistor. Now functioning correctly
checked transformer is getting power, 88v with phase shift at min and 218v at max. also checked transformer windings, 10 ohm primary 3k ohm secondary
Checked inductance coil, all good
checked relays, all working as should be
the only thing i cant check is the transformer output and if the HF capacitor is working, would a duff capacitor cause the HF to die? and thoughts appreciated!
