H & M Clipper help required

[kevinlms]

3 hours ago, smokebox said:

 

That listing is for 10 diodes!

That's right, 4 packets enough for 10 power supplies!

[Grovenor]

Quote

Further to earlier comments on the lethal mains voltage trains, (I was in Italy at the time and missed them!),

So you must be coming up on your 100th birthday very soon, let us know when so we celebrate.

Rgds

[melmerby]

1 hour ago, kevinlms said:

That's right, 4 packets enough for 10 power supplies!

Or

https://www.aliexpress.com/item/32916315837.html?spm=a2g0o.productlist.0.0.39524968D7Nz2d&algo_pvid=6a40675a-44b2-4c2c-b23d-bbf5aa75f6dd&algo_expid=6a40675a-44b2-4c2c-b23d-bbf5aa75f6dd-2&btsid=dba615e4-f294-4f7d-b4df-926256718141&ws_ab_test=searchweb0_0,searchweb201602_1,searchweb201603_55

 

10 complete bridge rectifiers for £1.33 inc post

[Il Grifone]

22 hours ago, smokebox said:

 

That listing is for 10 diodes!

 

Four make a bridge rectifier, so you get two for your money  (these are 1000 P.I.V. and 3A , which is more than enough for trains - 1N4007s will do at a push). There are also complete rectifiers available but they are more expensive and don't allow for pulse power (which may or may not be relevant).

[sharris]

1 hour ago, Il Grifone said:

There are also complete rectifiers available but they are more expensive and don't allow for pulse power (which may or may not be relevant).

 

By pulse power do you mean half-wave rectification? Unless you're going to put big smoothing capacitors on the output, even the full-wave rectified output of the simple controllers is pulsed to some extent. 

 

From what I remember the full wave/half wave switch on the Clipper and Duette opens up the bridge for half-wave, so if restoring one of these with silicon, individual diodes rather than an integrated bridge will be the order of the day. 

Edited October 21, 2019 by sharris
bad grammar

[melmerby]

summat like this:

[Il Grifone]

Pulse power gives only the half wave rectification. H & Ms 'vari-wave' *put a variable resistance in series with one wave to vary it's amplitude, which is very effective with all but the most stubborn motors ( I have one Hornby 0-4-0 which is still sprightly even at minimum!). Some motors are unhappy with it and overheat. My Rivarossi N gauge B & O C16 0-4-0 is one.

 

* A beefy wire-wound slider device!

There was much discussion at the time of its introduction as to whether it would cause demagnetisation of the motor.  I have never noticed any ill-effects.

[Il Grifone]

On 20/10/2019 at 15:27, Grovenor said:

So you must be coming up on your 100th birthday very soon, let us know when so we celebrate.

Rgds

 

It would be 15th January, but I'm not quite that ancient!    I was referring to  the comments not the trains. I might not have made my fifth birthday, if  my first electric train had been one of those rather than Hornby Dublo*....

 

The finned rectifiers were connected Negative pole - AC input - Postive pole - AC input - Negative pole with a link between the 2 negative poles, The pulse-power switch or 'Vari-wave' control replaced this link.

 

* It could have been! I already had Hornby 0 gauge clockwork, so converting to electric would have been a logical step.

Edited October 21, 2019 by Il Grifone

[AndyID]

There's a very elegant HD battery controller on eBay (US). If the shipping cost was less I'd use it in an electronic controller.

 

https://www.ebay.com/itm/Hornby-DUBLO-TYPE-B3-Battery-CONTROL-UNIT/303308217807?hash=item469e941dcf:g:nooAAOSwt8Jdllfq&redirect=mobile

 

No affiliation.

[PatB]

I often look at old controllers and think that their best use would be to provide a stylish and robust package for whatever flavour of electronic internals one favours. 

[melmerby]

14 hours ago, AndyID said:

There's a very elegant HD battery controller on eBay (US). If the shipping cost was less I'd use it in an electronic controller.

 

https://www.ebay.com/itm/Hornby-DUBLO-TYPE-B3-Battery-CONTROL-UNIT/303308217807?hash=item469e941dcf:g:nooAAOSwt8Jdllfq&redirect=mobile

 

No affiliation.

Rather interesting that Hornby calls it a battery controller when it could just as easily be a mains powered controller if a suitable power pack was used.

[kevinlms]

20 minutes ago, melmerby said:

Rather interesting that Hornby calls it a battery controller when it could just as easily be a mains powered controller if a suitable power pack was used.

Presumably because it came as part of a train set, without any mains power supply. 

[melmerby]

3 minutes ago, kevinlms said:

Presumably because it came as part of a train set, without any mains power supply. 

Which were often sold as an add on.

However years ago they were often called "battery eliminators" so maybe logical after all.

[AndyID]

I suspect it has resistance steps rather than variable resistance. If I buy it I'd rather not modify it. Steps would make things a bit tricky but not impossible.

[Il Grifone]

That's the one I referred to earlier (I think it was this thread!). It has a continuous wiper contact variable resistance.] similar to (the same as?) the one in the earlier black box.

 

At the time of it's introduction, (mid-fifties),  the sets were sold less power supply (something to do with the ramifications of purchase tax*) and I don't think this was ever sold in a set. It was sold as a battery controller, but would be OK fed from the DC output of a transformer rectifier. I suspect it was to avoid complications with the wiring, as the 12 volt DC uncontrolled outputs of Dublo transformer controllers were all on the same winding as the controlled output.

 

*IIRC a transformer was exempt tax, but became liable if included in a train set. Hence all you got was the black box rectifier/controller. and a separate (and extra cost) power supply had to be sourced. There were also problems with different mains voltages or even none at all. DC  mains were also to be found which needed a rotary converter (no switch mode power supplies then (apart from the vibrator power packs used to run a valve radio in your car - yes they were noisy and unreliable!).

[melmerby]

1 hour ago, Il Grifone said:

apart from the vibrator power packs used to run a valve radio in your car - yes they were noisy and unreliable!).

The vibrator contacts used to weld together and stop them working

 

A guy where I worked converted one of those car radios to run on 12v by modifying it to use very high mu RF valves and a transistor audio output stage.

It worked well.

Edited October 22, 2019 by melmerby

[Il Grifone]

Apparently (I never saw any) there were 12 volt valves designed especially for car radios. The advent of power transistors (e.g. OC35) killed those off. Germanium (p.n.p.) transistors were ideal for positive earth vehicles. Luckily silicon (n.p.n) transistors appeared about the time of the switch to negative earth.

 

Ford (and VW IIRC) clung to 6V electrics longer than most, but I suppose if you could only afford a Ford Popular, you weren't entitled to a radio in it (or a heater!).

[TheQ]

4 minutes ago, Il Grifone said:

Apparently (I never saw any) there were 12 volt valves designed especially for car radios. The advent of power transistors (e.g. OC35) killed those off. Germanium (p.n.p.) transistors were ideal for positive earth vehicles. Luckily silicon (n.p.n) transistors appeared about the time of the switch to negative earth.

 

Ford (and VW IIRC) clung to 6V electrics longer than most, but I suppose if you could only afford a Ford Popular, you weren't entitled to a radio in it (or a heater!).

I came across the 12V valves in " portable" military equipment, much smaller than a convetional valve, often metal cased rather than glass. If you didn't know what you were looking at, you'd think they were a very tall transistor

[AndyID]

10 minutes ago, Il Grifone said:

Ford (and VW IIRC) clung to 6V electrics longer than most, but I suppose if you could only afford a Ford Popular, you weren't entitled to a radio in it (or a heater!).

 

IIRC the 1968 VWs in the UK were 12 volt. The US might have been a year earlier. 6 volt systems worked well enough as long as all the connectors were in good shape. The biggest problem was that many people tended to overlook resistance in the return path. A solid ground connection between chassis and the transmission was essential for starting.

[Il Grifone]

By 1968 everything was 12V negative earth AFAIK. Nasties like vibrator power packs and 6V positive earth belong to the fifties/early sixties. My 1956 Ford Consul was already 12 Volt (positive earth though).

It would appear the the Beetle switched to 12V sometime between 1964 and  1968, but I couldn't find a definite date.

 

Lots of stuff on converting them to 12 Volt....

[Colin_McLeod]

1 minute ago, Il Grifone said:

Nasties like vibrator power packs ...........  belong to the fifties/early sixties.

 

I though these were still produced.  

Oh sorry.  Wrong Forum ;)  

[melmerby]

My first vehicle was a Ford 300E van (late fifties) Side valve engine, Vacuum wipers, 3 speed gearbox and 12v electrics.

I once had a old 1964 mini which I converted from positive to negative earth, mainly so I could use a negative earth transistor car radio, while I was at it I changed the dynamo for a Lucas 15ACR alternator.

[cliff park]

I'm glad we're back on car electrics, just for a moment I was afraid we were going off topic.

[kevinlms]

58 minutes ago, cliff park said:

I'm glad we're back on car electrics, just for a moment I was afraid we were going off topic.

This thread is about anything electrical and strange gremlins.

[Pacific231G]

3 hours ago, Il Grifone said:

Apparently (I never saw any) there were 12 volt valves designed especially for car radios. The advent of power transistors (e.g. OC35) killed those off. Germanium (p.n.p.) transistors were ideal for positive earth vehicles. Luckily silicon (n.p.n) transistors appeared about the time of the switch to negative earth.

 

Ford (and VW IIRC) clung to 6V electrics longer than most, but I suppose if you could only afford a Ford Popular, you weren't entitled to a radio in it (or a heater!).

I've just been looking at a 1945 US WD technical manual "Aircraft Electrical Systems" https://archive.org/details/TM1-406

Aircraft DC systems then were either 12V or 24V but from the examples given it looks like 12V was more common. 6V had presumably been found too unrellable for use in aircraft.  I've always understood that the development of low voltage DC equipment, particularly for aircraft instuments, during WW2 gave a real boost to the development of  model railways after the war. This was partly due to more powerful small motors but also the availability of large quanities of surplus equipment.

 

If you look at earlier H&M and other controllers there's no indication that they were intended for model railway use, the centre off control was marked normal and reverse not forward and reverse and the company described itself as "electro-mechanical engineers". I believe that this was to stay in the lower purchase tax category of scientific and educational equipment and avoid the higher purchase tax in the toy category. I do though seem to remembers seeing familiar H&M products in lab equipment supply catalogues especially for schools. In this category there clearly would be considerable value in the controlled voltage independent of load supplied by variable transformers rather than rheostats. I have wondered if these were originally developed for that market rather than model trains.