Degaussing MTC900..

[ircom]

I recently bought a used Hantarex MTC900 for my cab. During wiring I found out that the degaussing switch was missing. This should go to connection "CC" (on connection "CD" there is the Degaussing Coil itself connected; according to schematics I found on the net).

Connection "CC" is short-circuit, with a brown cable! Now I was wondering if this is ok? (see included picture).

1) Is this how it should be cabled, in order e.g. to have it degaussed automatically during poweron. Or is this completely wrong, or should I replace the short-circuit by a switch?

2) Do I really need 220V for degaussing? Now I have only 120V connected. If I need 220V for degaussing, can I connect it without an isolation transformer (see picture for schema). Currently I only use an isolation transformer with only a 120V output (and 220V input).

[grantspain]

If my memory serves me right that short plug acts like the switch.
You need 220-240v on the degauss for it to work.
You could take the wies from the primary(input side of the transformer),not many people recommend this because you do not have much protection against surges,but if you put a fuse on the live input (2-3amp) it should be fine-we used to do this all the time when building cabs in the 80s and never had a problem.
The degauss should only work for a few seconds when you switch the monitor on from cold,this is done by the PTC componant on your degauss circuit,if that goes short then your chassis fuse will blow.

[ircom]

I still wonder how a short plug can act like a switch?..

Shouldn't the degaussing be done for just a few seconds by applying the 220-240Volts? Isn't the 220-240V with the short plug on, applied all the time?

What exactly does the PTC component do?

Would appreciate any help with this, thanks!

[grantspain]

well thats what the ptc does,applies voltage for a couple of milli seconds then switches off,if you connected a switch to that plug even if you held it on it would do the same,some monitors have degauss switches and some dont.

[ircom]

That's the answer what I was looking for.

Now its completely clear to me, thanks for your help!

[Jess--]

the psu in my cab (hantarex us-250) takes the 220 straight from the mains input for the degauss, this is original as the cab had not been messed with at all when I got it.

for reference most hantarex monitors have a fuse onboard for the degauss circuit