Would a thin layer of Dielectric grease be good for something like that? The contact is on top, keeping it clean? Probably wouldn't hurt to take some compressed air and blow out the coil outside. Get that carbon powder out of it!

Thank you very much for the heads up. All the best . Rob

Interesting to note you freely handling unearth/grounded metal marts with the power on.

One way to clean the tracks is to use a pencil eraser, works well, no chems required, at least worth a try first.

Hi interesting videos I'm referbing one now . Do you know where I could get new brushes for it please. Kind regards

@jwflame

6 жыл бұрын

Got mine from RS components, uk.rs-online.com/web/c/power-supplies-transformers/transformers/variac-brushes/ You may need to get some which are larger and file them down if the exact size isn't available.

You should buy some spanners.

I have a Zenith Type 100-RM2b, (two outputs at 4 amps). I need two sets of brushes , can you tell me where you obtained yours, (or did you make / modify them) I am sure that there will be many viewers that would appreciate an answer?

@jwflame

8 жыл бұрын

+Robert Riley Mine were obtained from RS, uk.rs-online.com/web/ and had to be filed down, as the exact size was not available.

@sbusweb

8 жыл бұрын

+John Ward Do you just-so-happen to have the RS part-code you got? I ask as I'm quite sure I've got exactly the same 8A variac at another site, and it should have new brushes too (in this case part-chipped off, rather than worn, limiting the current capability)... Also, I was considering adding a soft-start function with either serious-thermistor or some sort of press-switch+resistors, as I had trouble with that inrush-current myself, n the past, and was about to feed my workbench sockets from a B6 10mA crabtree RCBO that might not like the inrush... With many thanks,

@robertriley4140

8 жыл бұрын

+sbusweb I used uk.rs-online.com/web/RS 347-3849 brushes in my refurb' as I will never use more than 3 Amps. I used the remains of the original brushes to form a template, (by gluing them to an old piece of PCB) this held the new brush in place whilst I reduced the thickness of the new brush using wet and dry paper. Its a messy job so do it under gentle running water. hope this makes sense

I might have opted just going for the pressure washer for this one.

256 volts? Isn't that way over the regulations? Isn't the UK the same as the rest of Europe at 230v +-10v? The maximum therefore being 253v?

@jwflame

9 жыл бұрын

Paul Hughes Yes, maximum is 253 so it was over. The voltage here is usually at the upper end of the allowed limit, typically 250. It was probably higher when the video was done as it was recorded at 2am, when there would have been minimal load on the system.

@billcogneeto7286

Ай бұрын

NO. Volts and RMS volts are not the same. Using a volt meter with out RMS the peak volts can be 255 at the plug and 285 At the output of the veriac if wired for full out put voltage. Individual locations may vary. Mains voltage is quoted in volts RMS not peak volts.

How to design a variac ?like turns per volt and core area

@jwflame

5 жыл бұрын

en.wikibooks.org/wiki/Electronics/Transformer_Design

The brushes look 'new' to me. It's not an electric motor - so those brushes would outlast you !

@David.R.H

Жыл бұрын

Who are you?