Where to buy rotary switch and digital panel meter?

These switches might do as they are ceramic:

On Sun, 23 Jul 2006 21:26:57 +0100, Dave had this to say:

Try:

Thanks, for some reason I hadn't thought of eBay for this sort of thing! They're actually a bit too pricey for what they are but looking at the pics has given me the idea of just getting a standard 2 wafer rotary and removing alternate contacts to improve the voltage rating - unless I can find something that's actually rated for what I need.

Dave

IF you've been to Farnell you will have seen their 1999vac fullscale meter.

As for the switch, the voltage will likely restrict you to industrial control switches which are not cheap and made up with switch modules fitted onto a detent mechanism. I agree - not easy to find.

A low voltage switch plus relays might be workout cheaper?

Good Luck

Bob

On Sun, 23 Jul 2006 21:13:18 GMT, "Bob Minchin" had this to say:

I don't know if it's still possible to get "Yaxley" switches, which were very popular in the 60s. There were similar ceramic things, which were great for high voltages.

Hang on a mo...

Dives into shack - bottom drawer of desk I think...

Eureka - I have a 2-pole 4 way ceramic switch which just wants a bit of a clean-up with Servisol. It's yours for the cost of postage...

Thanks Frank!! I've sent you an email.

Dave

... snipped

Thanks Bob, TBH I'd missed it but maybe it was the price that put me off. When a cheapy DMM can be had for £10-20 it seems a bit much to pay £50 for a DPM - maybe I'm just being too tight ;-) Quack!

Dave

A hidden advantage of using a low voltage DMM is that it needs an attenuator. This means that a high voltage attenuation resistor can be placed in series with every incoming hv line. These resistors usefully limit any transient or fault currents through the switch.

Have a look at Lascar. They'll be easier to mount than trying to adapt a cheap DVM.

Dave

Don't use wafer switches over 50V, unless they're designed for it (ceramic wafers and physical gaps). You get carbon tracking across the paxolin, no matter what distance.

Old valve radio wafer switches, or S/H industrial cam switches are the things to use though. Not cheap new, but they're around S/H. Greenweld used to have loads.

I ordered a Moeller "voltmeter switch" (obvious when you think about it!) that's made for the job at £11.98 -25% +17.5% ... not too bad.

Dave

My old, but top of the range Maplin DVM with rotary switch went bang when measuring - or trying to - mains voltage. It was brass dust from the tracks bridging the insulation between them.

A not uncommon failing.

Switches for HV are made on different principles often.