Ekco AC18 HT Unit - using?

[Joe]

Shock risk is minimal — what you don't touch can't hurt you.

There's a higher fire risk but the biggest risk is to the PSU itself. I'd certainly connect it through a lamp-limiter, at least initially.

We all have different attitudes but if it were mine I'd simply get on and re-build it without bothering about how it was originally configured.

— Joe

[ppppenguin]

RCD and lamp limiter are your friends. Provided you don't put your handa anywhere daft you won't get a shock. Connect up a meter to measure the output before you switch on if you're worried. The biggest hazard is an electrolytic handing in its notice a bit rapidly. That's why a variac would be nice but a lamp limiter (start with a 40W bulb or even 25W if you have one) wil stop any serious damage. The purists would suggest trying to reform the caps but sometimes life is too short.

[pwdrive]

Yes, that electrolytic might be an addition ? Check out the connections count on that black multi job as shown here:

http://www.radiomuseum.org/r/ekco_ht_unit_ac18.html

Lawrence.

[SurreyNick]

Yep. Dump the extra electrolytic and they seem to match Lawrence. Good. One item resolved.
Luckily I have a lamp limiter and RCD and a small variac. The variac is only rated to 0.75a, but this unit is offering up 18ma max. I'll use all three and keep the fire blanket handy
I'll let you know how I get on.
Nick

[pwdrive]

Maybe the capacitors in the black box were electrolytics, testing them out of circuit with an analogue meter set to ohms might give some indication as to what's what inside that box, if they are paper and electrically leaking the resistance should be the same when connecting to the meter one way then the other way (reverse connection) if they are electrolytic the readings might be different when the test connections are reversed...possibly.

Lawrence.

[SurreyNick]

Mm. I will do that. Thanks Lawrence.
Nick

[AlanBeckett]

So, apart from having a simpler SG Circuit, and assuming that the 'Black Box' is three Capacitors, it looks like mine:-

   

Alan

[ppppenguin]

The 3 caps in the black box will definitely be electrolytic. The technology of the time wouldn't have made those values possible with paper dielectric in that size of box. Alan's circuit looks about right to me.

[pwdrive]

That would make sense Alan, could well be the same values as well.

Lawrence.

[AlanBeckett]

I re-stuffed mine. As it was Cardboard and mostly covered by a Bracket it looked just about acceptable.

                   

Alan