Author Topic: UK electronics forum  (Read 9255 times)

Offline Will_D

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UK electronics forum
« on: December 16, 2014, 09:15:03 AM »
Can anyone recommend a good UK based electronics forum.

By good I mean as good,great and friendly as MadModders
 :ddb:   :nrocks:  :ddb:
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Offline John Swift

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Re: UK electronics forum
« Reply #1 on: December 16, 2014, 11:32:33 AM »

Hi Will

Have you any electronics experience ?

I'm not a member my self , but have you had a look at  :-

http://www.epemag3.com/epe-chatzone.html
http://www.chatzones.co.uk/discus/messages/7/15585.html?1416590383

    John

Offline awemawson

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Re: UK electronics forum
« Reply #2 on: December 16, 2014, 11:59:28 AM »
I hesitate to recommend any. I was a member of one electronics forum, and someone wanted pictures of the Traub lathe I'd been working on, so I posted a link to the thread here. Where upon 'The Sword of Damocles' fell on me and I was roundly condemned for linking to other forums. They were an ignorant lot anyway  :ddb: 
Andrew Mawson
East Sussex

Offline John Rudd

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Re: UK electronics forum
« Reply #3 on: December 16, 2014, 01:24:14 PM »
Will,
I'm over on epe forum as Chippie...( a loose connotation derived from integrated circuits...ic, chip etc. )
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Offline Will_D

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Re: UK electronics forum
« Reply #4 on: December 16, 2014, 02:54:47 PM »
Thanks for the info!

In the 60s I used to get Wireless World then moved to Practical Radio then into Practical Electronics, so yes I've fried a few bits and survived the odd 350 volt shock from a traffo!

Best thing every was a mains traffo which was fitted with a diode rectifier valve that emitted a large amount of UV and the affore mentioned 350 v DC

Am trying to get the Microwave Oven Transformer Induction heater project working.

Already got the M.O.T spot welder doing 0.8 to 0.8 mm stainless. Not that I want to weld sheet its more for stainless mesh/fine gauze for filtering wort!

I just love mixed hobbies!

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Offline John Rudd

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Re: UK electronics forum
« Reply #5 on: December 16, 2014, 02:58:32 PM »
I'm interested in the spot welder if you can give some detail please....website link etc...
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Offline Will_D

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Re: UK electronics forum
« Reply #6 on: December 16, 2014, 04:11:14 PM »
I'm interested in the spot welder if you can give some detail please....website link etc...
Hi John,
There are a lot of you tube vids and googlformation. Here is at least an English one (given the accent!)

https://www.youtube.com/watch?v=RnjF5Hj2Udg

Basically remove the secondary and add two turns of the biggest wire you can fit. Mine is 85mm^2 gives 2 volts and more than 800 Amps. For the prototype tips just used some M8 * 0.8mm Mig welder tips. These are as cheap as chips even in Dubland ( €1-20 each) easier than turning down copper bar. I turned them down to about 3mm dia at the ends.

Can only apply force with a pair of pliers (Need to build the arms etc) but as "proof of concept" it works

A small spot welder for under a fiver :clap:

BTW: The 85square was found in ICL's skip in the mid 70's (BIG mainframe computer earth straps)


Should really do a  :proj: thread
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Offline John Rudd

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Re: UK electronics forum
« Reply #7 on: December 16, 2014, 04:14:35 PM »
I'm interested in the spot welder if you can give some detail please....website link etc...
Hi John,


Basically remove the secondary and add two turns of the biggest wire you can fit. Mine is 85mm^2 gives 2 volts and more than 800 Amps. For the prototype tips just used some M8 * 0.8mm Mig welder tips.

A small spot welder for under a fiver


Should really do a  :proj: thread

Thanks for the info... :thumbup:

Yup you should do a thread on this.....
eccentric millionaire financed by 'er indoors
Location:  Backworth Newcastle

Skype: chippiejnr

Offline John Swift

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Re: UK electronics forum
« Reply #8 on: December 16, 2014, 04:19:56 PM »

Hi Will

I started in the late 60's building projects in Practical Wireless
 
the PW  valve radios powered by a B 136   90V /1.5V  battery worked

don't know about any one else who received a Philips EE kit for Christmas but
I had problems with germanium transistor radio circuits in the Philips EE kit
until I replaced the AF116 supplied with an older OC44  :doh:

by 1980 Practical television had published 3 or 4 colour TV projects
 Christmas 1981 I built the Forgestone  26" colour TV (and yes It worked first time :D )




Hi John

this  may give you some ideas :-
 http://makezine.com/2013/11/18/building-a-spot-welder-from-a-transformer/

a few days age I was looking   for a DIY transformer kit
for a mains power supply to replace the 90V and 1.5V  batteries for a radio

via a page for the maplin millennium valve amplifier I found Danbury electronics make  50 VA & 100VA DIY transformer kits  :-

http://livinginthepast-audioweb.co.uk/index.php?p=xfrmrvt227
http://livinginthepast-audioweb.co.uk/index.php?p=xfrmrvt228

the Wire Size Guide could be usefull


    John







Offline awemawson

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Re: UK electronics forum
« Reply #9 on: December 16, 2014, 04:47:00 PM »
"I started in the late 60's building projects in Practical Wireless "

Oh Gawd now I feel really old! My first project was a crystal set built on the kitchen table using a copper iron heated on the gas stove. 1959 I think  :bugeye:
Andrew Mawson
East Sussex

Offline John Swift

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Re: UK electronics forum
« Reply #10 on: December 16, 2014, 04:55:27 PM »
Andrew

"Oh Gawd now I feel really old "

that's what I thought a few weeks ago when I realised I can apply for a bus pass in a couple of months  :(

   John

Offline vtsteam

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Re: UK electronics forum
« Reply #11 on: December 16, 2014, 07:29:27 PM »
I've made a spot welder from a big transformer before. The hard part was pulling out all the old wire from the secondary. It was varnished in there, or something, and tight as heck. But eventually I got it chopped out.

Later I bought  Harbor Freight spot welder for $125, on sale, and have used that a lot.
I love it when a Plan B comes together!
Steve
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Offline geoff_p

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Re: UK electronics forum
« Reply #12 on: December 16, 2014, 10:58:12 PM »
I don't really want to sidetrack this thread but ...
Back in the early '70s, I was a draughtsman at Martin Electric, Theale, where we made spot welders.  Our 'small' ones used a 25kVA transformer, which delivered a mere 500,000 Amps - the secondary-cables were about 1.5 inches diameter.  All parts of the secondary circuit i.e. transformer, cables and welding-head, were water cooled,  they reckoned the current 'leaked' through the water was negligible compared to what went through the weld.

The transformers had 3-phase primary windings and a secondary comprising two turns.  Each of those turns was cast copper, up to an inch by four cross section, with a coolant-pipe cast-in, in the form of a U-shape and connected in series.  The secondary voltage was probably only a Volt or two, it was Amps we wanted!

The controllers comprised a timer switching thyratrons - the valve-type precursor to the thyristor (thyratron transistor ) - on all three phases of the mains power.

Since then, my interest in electronics has used FAR smaller currents but has gradually dwindled.  I built my first CNC machine to overcome my failing eyesight so as to drill the holes in my PCBs.

And that in turn has led )eventually) to my current build of a CNC milling-machine.

Which is calling me just now to do some more work.

Geoff
Thailand

Offline DavidA

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Re: UK electronics forum
« Reply #13 on: December 17, 2014, 07:43:38 AM »
...My first project was a crystal set ..

I still have a genuine cat's whisker. 

1959.... The year I left school.

Dave.

Offline BaronJ

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Re: UK electronics forum
« Reply #14 on: December 27, 2014, 09:36:04 AM »
Hi Guys,

Talk about dating ourselves  :bugeye:

I got my first "cats whisker" from the radio shop across the street.  That would be around 1955, I was ten.  The chap who ran the shop was an ex RAF wireless technician.  My dad bought a 10 inch Bush TV from him in 1952/3 and the whole street was in our house watching the coronation of the queen.  I used to spend hours in his shop.  Mother always said she knew where to find me when a meal was ready.

:med: :med: :med:


Best Regards:
                     Baron

Offline Joules

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Re: UK electronics forum
« Reply #15 on: December 27, 2014, 11:00:37 AM »
Cooor,
         miss the old days of forces surplus shops.  We use to have a gem near us and I would truant from school to go rummage through the old valves and chassis, oxygen bottles and cathode ray tubes etc that they had.  Late 70's so I feel quite young here  :D
Honour your mentors, and pay it forward.