Shandon Southern V500/150 power supply - UK Vintage Radio Repair and Restoration Discussion Forum

daveobuchanan · 27th Jan 2019, 12:55 pm

Hi, got this a while ago, probably working condition. I am thinking of turning it on, i.e. bringing it up gently on Variac.
Will check obvious components for shorts first,
Is anyone familiar with this device? Any obvious components that I should check.
Thanks

daveobuchanan · 28th Jan 2019, 8:53 am

I am pleased to report that it seems to be working. Well no explosions so far, I haven't wound it all the way to 240v yet, just a little bit of debris in the current meter getting stuck. I have never used one like this before. It uses the triac type device to control the output voltage / current, with no linear regulator stage. Feedback loop is thus quite slow... and strange buzzing noises when adjusting the pots.

turretslug · 28th Jan 2019, 10:32 am

I'd been looking for parallelled biggish valves or significant amounts of heatsinking, but the use of a triac would explain the absence!

Looks like a useful bit of kit- slightly puzzled by the two normal/reverse switches.

Alistair D · 28th Jan 2019, 12:36 pm

I have come across 500V long time constant power supplies before. My suspicion is that yours was intended for electrophoresis - no I don't exactly what that is either.

A quick search on the internet seems that it is indeed for that application.

http://collection.sciencemuseum.org....ntific-limited

Perhaps the parent company might still have some service information they could send you.

Al

daveobuchanan · 28th Jan 2019, 1:25 pm

Ahh. Please excuse my dyslexic moment.... Shand-Shandon

I was a bit puzzled before i had the lid off by how it worked. Not that heavy, which is nice. A bit scary that the output is those 2 big caps in series, 200uF, would pack quite a bang if shorted at 500v, but there is some series resistance. Probably ought to trace out that bit of the circuit for peace of mind. Those switches reverse the polarity of the output. There is only one output though so commoning the black terminals and reversing one switch will short out the PSU. The rather complicated switches are actually automotive 60's paddle switches with a spring mounted sliding blanking plate.

Diabolical Artificer · 28th Jan 2019, 1:58 pm

I have a big 500v 3A jobbie, triac regulated like yours, it makes all sort of odd noises, buzzing when cranking V up etc. OP isn't clean with spikes etc but its grand for testing big OP valves and prototyping circuits.

Andy.

27th Jan 2019, 12:55 pm	#1
daveobuchanan Pentode Join Date: Jul 2012 Location: Cambridge, Cambridgeshire, UK. Posts: 136	Shandon Southern V500/150 power supply Hi, got this a while ago, probably working condition. I am thinking of turning it on, i.e. bringing it up gently on Variac. Will check obvious components for shorts first, Is anyone familiar with this device? Any obvious components that I should check. Thanks Attached Thumbnails

28th Jan 2019, 8:53 am	#2
daveobuchanan Pentode Join Date: Jul 2012 Location: Cambridge, Cambridgeshire, UK. Posts: 136	Re: Shand Southern v500/150 power supply I am pleased to report that it seems to be working. Well no explosions so far, I haven't wound it all the way to 240v yet, just a little bit of debris in the current meter getting stuck. I have never used one like this before. It uses the triac type device to control the output voltage / current, with no linear regulator stage. Feedback loop is thus quite slow... and strange buzzing noises when adjusting the pots.

28th Jan 2019, 10:32 am	#3
turretslug Dekatron Join Date: Nov 2011 Location: Surrey, UK. Posts: 4,395	Re: Shand Southern v500/150 power supply I'd been looking for parallelled biggish valves or significant amounts of heatsinking, but the use of a triac would explain the absence! Looks like a useful bit of kit- slightly puzzled by the two normal/reverse switches.

28th Jan 2019, 12:36 pm	#4
Alistair D Nonode Join Date: Jan 2010 Location: Edinburgh, UK. Posts: 2,008	Re: Shand Southern v500/150 power supply I have come across 500V long time constant power supplies before. My suspicion is that yours was intended for electrophoresis - no I don't exactly what that is either. A quick search on the internet seems that it is indeed for that application. http://collection.sciencemuseum.org....ntific-limited Perhaps the parent company might still have some service information they could send you. Al __________________ I won't tell you how I discovered that.

28th Jan 2019, 1:25 pm	#5
daveobuchanan Pentode Join Date: Jul 2012 Location: Cambridge, Cambridgeshire, UK. Posts: 136	Re: Shand Southern v500/150 power supply Ahh. Please excuse my dyslexic moment.... Shand-Shandon I was a bit puzzled before i had the lid off by how it worked. Not that heavy, which is nice. A bit scary that the output is those 2 big caps in series, 200uF, would pack quite a bang if shorted at 500v, but there is some series resistance. Probably ought to trace out that bit of the circuit for peace of mind. Those switches reverse the polarity of the output. There is only one output though so commoning the black terminals and reversing one switch will short out the PSU. The rather complicated switches are actually automotive 60's paddle switches with a spring mounted sliding blanking plate.

28th Jan 2019, 1:58 pm	#6
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,661	Re: Shand Southern v500/150 power supply I have a big 500v 3A jobbie, triac regulated like yours, it makes all sort of odd noises, buzzing when cranking V up etc. OP isn't clean with spikes etc but its grand for testing big OP valves and prototyping circuits. Andy. __________________ Curiosity hasn't killed this cat...so far.