Can anyone identify this DC controller?

[DCB]

Can anyone identify this DC Controller.  It has no ID at all.   Voltmeter shows 12 volts on full power off load, 0 volts rising through 0.1 etc on minimum power off load , there is a separate reversing switch for the controlled output and the uncontrolled looks to have a big capacitor across it.

It's been kicking around the shed for years and as we are planning to de clutter somewhat it would be nice to know how to describe it on eBay.

[JohnDMJ]

Description should include the fact that it's home made, non-proprietry.

 

I'd offer £1.00 just to get it OUT of general circulation! I can see no evidence that it would achieve PAT Certification.

[Michael Hodgson]

Definitely home made - not dissimilar to something I built decades ago.

Looks as though the case will be properly earthed, and built to the standards of the time but it's very much yesterday's technology.

[SamThomas]

A friend of mine does PA Testing & this is a perfect example of why he does not carry out safety tests for modellers. It may have given good service in the past but as things have moved on time for it to go. Failing it could cause bad feeling.

 

My advice would be to remove the mains cable from the plug & crush it with something like a sledgehammer or dispose of it at the local waste recycling facility.

 

 

[kevinlms]

That looks like it could be a home made controller *, in a custom made box.

 

The real test for passing a PAT test is whether it is properly earthed or not, nothing there to suggest that it is, as we cannot be sure what the mains cabling is like.

 

There is also the fact that is it a good electronic controller? We don't know. I suspect not very good, as it has a transformer with only 9 volts AC output, thus why it is 12 volts DC on no load. Certainly useless for David's outdoor railway!

 

Personally, I think I'd dismantle it for spares. It certainly is something that should NEVER be put on eBay.

 

* Was going say from a kit, but no evidence of a PCB.

[John M Upton]

As a former PAT tester, I can tell you straight away I would cut the plug off it and slap a condemned red sticker on it before even bothering to get the testing rig out.

 

Strip it and bin it, certainly DO NOT sell it on Ebay or anywhere else for that matter.  I cringe in horror every time I do a Job Lot search on Ebay and "vintage" controllers come up, many, indeed most of which should be crushed.

[Nearholmer]

I think you are being a bit extreme there JMU, because with good earthing, and ideally with a local RCD, metal-cased, single-insulated kit can be used safely.

 

It might not be a good idea to entrust its ownership to the uninitiated, so I agree it’s maybe best not on eBay, but collectors of vintage kit know what they’re about. People even run “mains through a light bulb and rheostat” set-ups under controlled conditions.

 

Genuinely early, by which I mean pre-c1930, which this clearly isn’t, electrical appliances were seriously interesting, and are now astonishingly rare because they were junked due to safety deficiencies, so IMO the crusher should only be deployed judiciously.

 

 

Edited August 28, 2021 by Nearholmer

[Michael Hodgson]

As I understand it the regulations don't require double insulation.  I would expect anybody doing PAT testing to check the earth continuity.  On the assumption that it is in good order (and I no obvious reasons to expect that not to be the case) surely it would be compliant?

[SamThomas]

1 hour ago, Michael Hodgson said:

As I understand it the regulations don't require double insulation.  I would expect anybody doing PAT testing to check the earth continuity.  On the assumption that it is in good order (and I no obvious reasons to expect that not to be the case) surely it would be compliant?

The fact that there is no rating plate or any other indication of what it actually is is enough to fail the first "test" of a PAT - visual inspection.

 

Also, FWIW RCD's are not the be all & end all - operating the "test" button is a very basic & inaccurate test as to the effectiveness of the actual device.

[Nearholmer]

I think that here we are bumping-up against the difference between a quick and simple PAT that is ideal for dealing with things in a commercial environment, and a knowledgable electrical engineer or the like being able to assess the safety of a piece of kit for their own use.

 

An item might fail the first, which is purposely designed to err well on the side of safety, yet still be perfectly safe.

 

Im not, BTW, suggesting that PAT-as-practised is a bad or unnecessary thing, it’s saved thousands of lives, but what I am saying is that it’s not the be all and end all, provided (and this is the serious bit) the individual making any assessment is truly, deeply competent to do so.

[JohnDMJ]

5 hours ago, Nearholmer said:

I think you are being a bit extreme there JMU, because with good earthing, and ideally with a local RCD, metal-cased, single-insulated kit can be used safely.

 

It might not be a good idea to entrust its ownership to the uninitiated, so I agree it’s maybe best not on eBay, but collectors of vintage kit know what they’re about. People even run “mains through a light bulb and rheostat” set-ups under controlled conditions.

 

Genuinely early, by which I mean pre-c1930, which this clearly isn’t, electrical appliances were seriously interesting, and are now astonishingly rare because they were junked due to safety deficiencies, so IMO the crusher should only be deployed judiciously.

 

 

 

As also someone who has the qualification to PAT certify equipment, @John M Upton's remarks are relatively understated.

 

The only thing plausible with that piece of trash is, as has already been stated, condemnation by sledge hammer!

 

All too many railway modellers have little or no comprehension of electricity and how components can degrade over time.

 

If anyone calls, in my professional capacity, to discuss anything Hammant & Morgan, I will give them concise answers and mention asbestosis!

 

IMHO, the equipment should be condemned and the user certified!

[stewartingram]

Well as a retired electronics/quality engineer, I wouldn't say no to it if I was offered it. I'd not just use it straight away without checking it over first for safety. It shouldn't be passed to the unwashed, but a sledgehammer is cruel. Whatever happened to recycling....

[cliff park]

As another (retired) electronics engineer I suspect that the sledgehammer brigade are just frightened of things they don't understand.

I have told this story on here before. My first experience with a PAT guy was when we brought in external contractors, instead of doing it ourselves. He cut the mains plugs off half a dozen monitors and condemned them because there was no earth continuity to a metal screw he found in the case. They were all double earthed with no earth connection.

Edited August 28, 2021 by cliff park
Story added

[Dagworth]

6 hours ago, JohnDMJ said:

As also someone who has the qualification to PAT certify equipment

As someone "qualified" you should know then that there is no requirement for a person undertaking such inspection to be qualified, the regs just require competence, and also you should know that PAT is not even a thing anymore, now being superseded by the 5th edition of the Code Of Practice for the In Service Inspection and Testing of Electrical Equipment, which does not mention Portable Appliance Testing anywhere except in the introduction as a historical note of how the code came into being.

As long as the earth is good, the fuse is correct, the cord in good condition and the device passes an insulation test there's no reason to condemn it.

 

Andi

 

 

Edited August 28, 2021 by Dagworth

[DCB]

Thanks folks, It may well be home made.  Its case is earthed nicely as are the individual components, it looks batch built.  It would be nice to know what that big capacitor was for, points? 

[Dagworth]

1 hour ago, DCB said:

It would be nice to know what that big capacitor was for

Smoothing the ripples of the output from the rectifier, the electronics of the controller prefer smooth DC rather than DC pulsing 100 times a second.

 

Andi 

Edited August 29, 2021 by Dagworth

[kevinlms]

7 hours ago, cliff park said:

As another (retired) electronics engineer I suspect that the sledgehammer brigade are just frightened of things they don't understand.

I have told this story on here before. My first experience with a PAT guy was when we brought in external contractors, instead of doing it ourselves. He cut the mains plugs off half a dozen monitors and condemned them because there was no earth continuity to a metal screw he found in the case. They were all double earthed with no earth connection.

Similarly I worked at a place where all our electrical tools were going to be tested by a guy who had recently done the course.

The day before mine were to be tested, I heard through the grapevine, that he was rejecting every soldering iron he tested, because the metal part of the irons weren't earthed - I should hope not on double insulated tools!

 

So I had an opportunity to take my work issued soldering iron home (almost brand new) and substitute it for a much older one from home. It duly failed and it was confiscated and a replacement ordered. So I ended up with 2 new irons! Every single person received a new soldering iron and no question, ever asked.

[kevinlms]

18 hours ago, Michael Hodgson said:

As I understand it the regulations don't require double insulation.  I would expect anybody doing PAT testing to check the earth continuity.  On the assumption that it is in good order (and I no obvious reasons to expect that not to be the case) surely it would be compliant?

Actually most equipment that is going to fail, fails before you get any tools out.

 

The first thing you ever do is a visual inspection. Things like damaged plugs, cords are the first thing likely to bring them undone. Next is to look for damaged parts or safety covers that type of thing. It is a safety test first, not just electrical safety.

 

Any problem(s) there and it's a case of 'Good bye', until it can be repaired, if not scrapped. Only then do any tools come near. Multimeters and Meggers are quite adequate for testing. No expensive PAT testers are required - although they make sense if doing a lot of testing.

 

 

I had a railway modeller give me half a dozen controllers for inspection. A couple were low voltage input only, so no requirement for testing at all.

2 passed, a 3rd had a damaged mains cord, of which I told the owner that if the cord was replaced, it would probably pass (he later gave it to me again and so I tested it and it did pass).

The last item, I told him that I refused to test it and to bin it!

 

He wasn't exactly thrilled at the results (I'm sure he expected a formality - not if my names going on it!), but did stop a couple of dangerous items going on eBay!

[SamThomas]

There are many people out there who have "done the course" but no amount of (expensive) "training" will teach experience which is why we have examples of class II being failed.

 

On retrospect I do agree that the controller depicted could be fine for use by someone with practical electrical (as opposed to electronic**) knowledge if proved to be safe within a controlled environment, but equipment like this should never be used by the general masses.

 

As for recycling, then there is the local recyling facility (after the slegehammer).

 

** I have known & met quite a few very knowledgeable electronics (as opposed to electrical) engineers & few of them could be trusted to even replace a 13a plug.

[spamcan61]

36 minutes ago, SamThomas said:

 

 

** I have known & met quite a few very knowledgeable electronics (as opposed to electrical) engineers & few of them could be trusted to even replace a 13a plug.

I'm more of an electronics engineer than electrical, but I agree; I did hear a colleague once say, with regard to a 240VAC circuit, " it's AC so it doesn't matter which way round we connect it" - well OK go poke a live terminal then, followed by a neutral one, see if they sting the same!

 

In terms of the controller in question methinks it wouldn't gain UL/CSA/CE certification but it doesn't look much worse than some Far Eastern consumer electronics I've had to bits.

[t-b-g]

If there is concern over the mains side of the unit, which appears to be supplied by RS components, dating it to post 1971, then one option would be to just replace the transformer with a modern one which does meet present day standards. That could be done easily by having a sealed unit transformer to modern standards outside the box and just feeding the low voltage AC output into the unit illustrated, connecting the wires to wherever the AC output of the old transormer went.

 

It the controller itself works well and drives trains nicely, it seems a shame to treat it as junk.

 

I have built up a collection of a few older type controllers, luckily for me all panel mounted types with no mains anywhere near them, fed from separate transformers and they are really good in terms of the control they give.

 

I would presume that as far as low voltages are concerned, we are still pretty much OK doing our own, unqualified bodging! Otherwise we would all need to pay qualified electricians to wire our layouts. 

[Crosland]

2 hours ago, spamcan61 said:

I'm more of an electronics engineer than electrical, but I agree; I did hear a colleague once say, with regard to a 240VAC circuit, " it's AC so it doesn't matter which way round we connect it" - well OK go poke a live terminal then, followed by a neutral one, see if they sting the same!

 

Given what I have seen of what "professionals" are capable of, I would NEVER try touching the neutral

 

 

 

[AndyID]

3 hours ago, Crosland said:

 

Given what I have seen of what "professionals" are capable of, I would NEVER try touching the neutral

 

 

 

 

In this part of the World both sides are "hot" on a 240 volt circuit  (not that you'd be likely to find a controller running on 240 although I did run one I brought from the UK that way for a bit but it's long gone now ).

 

And just my usual reminder that 240 is four times more likely to be lethal than 120. It's the power dissipated as does you in.

 

 

[kevinlms]

23 minutes ago, AndyID said:

 

In this part of the World both sides are "hot" on a 240 volt circuit  (not that you'd be likely to find a controller running on 240 although I did run one I brought from the UK that way for a bit but it's long gone now ).

 

And just my usual reminder that 240 is four times more likely to be lethal than 120. It's the power dissipated as does you in.

 

 

Yeah, but you need thicker wires to do anything useful, like boiling an electric kettle!

[AndyID]

19 minutes ago, kevinlms said:

Yeah, but you need thicker wires to do anything useful, like boiling an electric kettle!

 

Electric kettles work fine on 120 anyway but If that's a major concern you can always have a 240 outlet installed. And line to earth will still only be 120 volts . You have to work quite hard to get a 240 volt jolt here.