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Battery Eliminator.

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Anonymous
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I've wondered about the wisdom of posting this.  Apologises to Mrs Ticktock if Chris makes a mess. :D  Seriously, if anybody is daft enough to copy it that's their funeral - probably literally, you have been warned do not attempt this.

Any road, here is the beast in question:-

Forum 135
Click to see full size image

It appears to work but I haven't yet tested it on the radio.  I'm dog sitting and it's best done when I can concentrate fully.

Cheers

Joe

 
Posted : 02/08/2011 12:12 pm
crustytv
(@crustytv)
Posts: 12423
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Jeeez!!! now I like knocking up hardwired-frankenwooden-projects but that's frankenwooden-scarey!!!

Next you will be creating EHT ones.

seriously very interesting and I'm curious.
Chris

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Posted : 02/08/2011 12:25 pm
Anonymous
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Here's the circuit:

Forum 136
Click to see full size image

I got the idea from a capacitor reformer circuit.  I ran my version passed a very well qualified electronic designer who didn't actually faint, so  I thought it was worth trying.  Capacitor testing is another use for it.

When it's finished it will be neater than that and will also have a transformer/LM317 for the LT.

The construction method is one  I saw a kid using to make crystal sets on 'Why Don't You?' back in the day.

- Joe

 
Posted : 02/08/2011 12:31 pm
Cobaltblue
(@cobaltblue)
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Nothing wrong with that construction 8))

It was how all the radios in Ladybird Book Building a Transistor Radio were built.
I built one using original parts with my nephew a couple of years back it was brilliant.
The is a page about it here http://homepage.ntlworld.com/henry01/la ... _radio.htm
You can build surprisingly complex circuits as long as you have decent length wires.
Enjoy  😉
Mike T

I don't care if it was a bargain whats it doing on my kitchen table. www.cossor.co.uk

 
Posted : 05/09/2011 8:49 pm
Anonymous
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How much current are you intending the 82V supply to provide? The average 4 valve battery set needs 90V at around 10mA.

Al

 
Posted : 05/09/2011 11:29 pm
Anonymous
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My Bush BP90 should take 10mA but actually draws 12mA.

If I did my sums right (and there's always a first time) it'd give about 30mA through a dead short, or at least until something blew.

Since making that death-trap I haven't actually used it as I like the radio on batteries for portability's sake.  

- Joe

 
Posted : 05/09/2011 11:38 pm
Anonymous
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Joe!

I have just had another look at you picture. Are you supplying the mains directly to this circuit? What are you planning the the circuit to be used for?

This type of circuit must never be posted on any kind of public forum!

Al

 
Posted : 05/09/2011 11:39 pm
Anonymous
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As I said, it isn't used AT ALL.

- Joe

 
Posted : 05/09/2011 11:45 pm
Anonymous
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if it was tidied up and built inside a radio it would be no different than any ac/dc set with a wooden or plastic case, i dont think jo would use it on say a vidor with a metal face plate
rob t

 
Posted : 05/09/2011 11:53 pm
Anonymous
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It's easy to get a small  mains to 24 + 24 (two secondaries).

Put them in series and a voltage doubler.

resistor and 3rd cap to drop volts to between 75 and 105.

(135V no load)

I think the breadboard above should have a health warning!
Forum 137

This will be perfect. Use  3 x 100uF 150V (min) capacitors

Put 100K across C1 and C2

If radio is 6mA then R1 is twice as large!
R1 chosen for 12mA

R2 represents the Radio. Do not install it!

Download page for Duncan Amps PSU2 program used to verify and print the design. http://www.duncanamps.com/psud2/download.html
It won't design PSUs. But it help you adjust R1 and tell you what the ripple and output voltage is.

 
Posted : 06/09/2011 12:33 am
Lloyd
(@lloyd)
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I know I can be a nutter at times, but there's no way on this earth I would build that thing at the top!!! I'll stick to battery inverters..

Regards,
Lloyd.

 
Posted : 06/09/2011 12:56 am
Anonymous
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BTW, with a 12mA Radio the RMS current in R1 is about 30mA and RMS volts about 37V
So that is 1.1W

Use a 2.5W resistor. Or 2 x Series resistors at half value, or 2 x parallel at twice value and then 1W resistors are fine.

For a 9mA radio increase R1 to 2K2, but wattage is <900mW, so a 1.2W or 1.5W is OK

Likely 3 x 47 uF will work fine for a 10mA radio

 
Posted : 06/09/2011 12:59 am
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