Beer and Buckjumpers

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Steve Carter
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Re: Beer and Buckjumpers

Postby Steve Carter » Sat Feb 13, 2021 9:46 am

Terry Bendall wrote: It was however 60 years old so I have had good value.

That's the problem with a lot of manufactured things these days, they just don't last like they used to! :lol:
Steve Carter

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Paul Willis
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Smoke fairies (not the band)

Postby Paul Willis » Sat Feb 13, 2021 11:15 pm

Serjt-Dave wrote:Oh dear indeed Paul. Look on the bright side. At least there were no flames!

I hope you get your issue sorted.


Thanks Dave. Fortunately, it's wasn't too difficult to track down and solve.

Taking the lid off my home made controller box shows this. Small transformer, lots of space around it, outputs on the opposite side with wires connecting them:

Transformer smoke (1).JPG


The problem was this wire here, which had flexed too much and fractured. The puff of smoke was the 240v main input arcing across broken wires.

Transformer smoke (2).JPG


The transformer lives in a box when not needed. I only usually have it out when I'm testing stuff. So the lead gets a lot of being bent over and wiggled around to get it in and out. Anyway, it was a quick fix to trim a couple of centimetres off the end of the lead, and solder the two new clean exposed wires back on to the terminals. All sorted in a few minutes, and then it was back on testing duty:

Transformer smoke (3).JPG


Cheers
Paul
Beware of Trains - occasional modelling in progress!
www.5522models.co.uk

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Serjt-Dave
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Re: Beer and Buckjumpers

Postby Serjt-Dave » Sun Feb 14, 2021 8:58 am

Hi Paul. I'm glad it's all sorted and easily fixed. I've still got to go back to my control panel and fix a MERG booster panel I made last year.

All Best and Keep Safe

Dave

Terry Bendall
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Re: Beer and Buckjumpers

Postby Terry Bendall » Sun Feb 14, 2021 9:19 am

Paul Willis wrote:The problem was this wire here, which had flexed too much and fractured.


The solution is to make up some sort of clamp to hold the mains cable so that it does not flex. Possible ways of doing this are to:

(a) use the flex clamping strip from a standard 13 amp plug held in place with two small nuts and bolts. If I have a broken plug I usually save the clamp strip for just such jobs.
(b) use a strip of metal in the same way but round off the edges so that it does not cut into the cable covering.
(c) use a strip of suitable plastic to do the same job.
(d) find a plastic cable clip of an appropriate size - the type used to hold cable to a wall or similar. Remove the masonry nail and drill out the hole to take a small bolt.

In Paul's example the size of the box means that there is not a lot of room to do this. Using some tubular spaces to space the transformer away from the side of the box might work. Alternatively use the spacers but bring the mains lead in from the side. Another alternative would be to bend the cable outside of the box and put the clamp on the outside.

Terry Bendall

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Will L
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Re: Beer and Buckjumpers

Postby Will L » Sun Feb 14, 2021 11:48 am

I couldn't help wondering, as your transform bolts through your case (which is presumably plastic?) with the blots showing outside, shouldn't you you be earthing the transformer frame, as well as making sure the mains lead is securely clamped?

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Paul Willis
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Re: Beer and Buckjumpers

Postby Paul Willis » Sun Feb 14, 2021 11:51 am

Terry Bendall wrote:
Paul Willis wrote:The problem was this wire here, which had flexed too much and fractured.


The solution is to make up some sort of clamp to hold the mains cable so that it does not flex. Possible ways of doing this are to:

(a) use the flex clamping strip from a standard 13 amp plug held in place with two small nuts and bolts. If I have a broken plug I usually save the clamp strip for just such jobs.
(b) use a strip of metal in the same way but round off the edges so that it does not cut into the cable covering.
(c) use a strip of suitable plastic to do the same job.
(d) find a plastic cable clip of an appropriate size - the type used to hold cable to a wall or similar. Remove the masonry nail and drill out the hole to take a small bolt.

In Paul's example the size of the box means that there is not a lot of room to do this. Using some tubular spaces to space the transformer away from the side of the box might work. Alternatively use the spacers but bring the mains lead in from the side. Another alternative would be to bend the cable outside of the box and put the clamp on the outside.


Fantastic advice from Terry, as always. I am, of course, going to totally ignore it ;-)

Given that this transformer gets very occasional use for testing, I'll just live with the need to occasionally repair it. I had to do that once when I dropped it, and the weight of the transformer coil tore the bolt fixing it out of the side of the plastic box, necessitating a patch repair.

I never leave it plugged in and unattended, and I have the utmost respect for mains electricity, so I'm not going to push the boundaries of sophistication. One thing that I did think of is whipping out my hot glue gun and running a bead around the outside of the hole, to make an impromptu grommet. I may still do that as a quick fix...

Cheers
Paul
Beware of Trains - occasional modelling in progress!
www.5522models.co.uk

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Paul Willis
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Re: Beer and Buckjumpers

Postby Paul Willis » Sun Feb 14, 2021 11:52 am

Will L wrote:I couldn't help wondering, as your transform bolts through your case (which is presumably plastic?) with the blots showing outside, shouldn't you you be earthing the transformer frame, as well as making sure the mains lead is securely clamped?


Yes, and yes. But also I probably shouldn't ride powerful motorbikes at three-figure speeds[1], but I still do that!

Cheers
Paul

[1] Naturally, only where the relevant law permits <ahem>
Beware of Trains - occasional modelling in progress!
www.5522models.co.uk


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