Manual for Hunts CRB3 Capacitor Tester

[Alistair D]

It can be done with a centre off mains switch and a 2 pole mains coil relay. I will sketch something out and post it later.

Al

[Alistair D]

The drawing I promised in the last post.

Choose a relay with plenty of isolation between the 2 sets of contacts. Two separate relays is an option.

A simple and reversible way to attach the relay could be to attach it to a piece of ally. Drill a hole the diameter of the switch boss in it and use the switch to lock it to the back of the front panel.

It would also be a good idea to include a low value mains fuse.

Al

[Alistair D]

I didn't think that 3 pole on-off-on switches  were very common, however, I have just found this one on Ebay https://www.ebay.co.uk/itm/On-Off-On-3PDT-Toggle-Switch-250V-AC-15A-3-Pole/283440763590?epid=12031320056&hash=item41fe62d2c6:g:VC8AAOSwXdpcpeEN#rwid

The same result can be achieved using one of these instead of a relay. Before doing so you would have to totally happy that the switch gives enough isolation between the mains and heater poles.

Al

[ppppenguin]

I'm fairly sure I've got a couple of 4 pole on-off-on switches. If you're interested I'll dig them out and post a photo. Cost would be postage (small parcel, so £3.10) plus a donation to BECG: www.becg.tv

[Freya]

I have lots of relays so this approach would be preferred option. It must wait though as Hedghog demand is high again.
Thank you for the idea and the drawing.

[Alistair D]

More than one person has commented that the schematic is difficult to understand and I agree. To help understand what is going on I have prepared some simplified diagrams for the basic functions of the instrument.

As a result of seeing the diagram of the insulation and leakage functions I am now wondering what setting users use for reforming electrolytics.

Al

[Alistair D]

Well it took long enough but I have now managed to complete the full version of the manual.

If you find any glaring errors please let me know.

Al

[Freya]

Nice Job, thanks

[Bushbaby]

Wow - many thanks for this. One day I shall get around to repairing the one I bought several years ago.