Homebrew PCBs

I've been meaning to build a resistance solder unit. I went to the
local RS yesterday to see what types of transformers they had. They
didn't have anything close to what I hoped to find. Not deterred I
went to an electronics store. There sure were a number of large flat
screen tvs in for repair! I gave the tech what I hoped would be an
easy part to provide. Nope, he said,  try Jameco on line. So I came
home and I did. Either I'm not sure what to put in the filter or I'm
looking for an oddity.

I'm trying to build a resistance solder unit.

I've searched on-line.

For the curious here are a couple of links:

http://www.girr.org/girr/tips/tips1/solderer.pdf

But this one uses a battery charger. I was hoping for something a bit
smaller and more home-brew.

This is more like what I was hoping to find but a bit pricey:

http://www.istnet.net.au/~wamrc/res_solder/index.html


Yeah, I also went out to the Train Index. I have the Mainline Modeler
magazine. That's what started this train of thought.

And there is this reference too:
http://www.trainweb.org/bristol-s-gauge/Projects/rsu.html

So what the heck am I looking for???

I thought I knew!

One article suggests a transformer that takes house current and on the
secondary posts gives 6-8 volts AC at 3 Amps. That's what I was asking
for at the local stores.

Another articles says I need a filament transformer that provides less
than 7 volts at 6 or more AMPS.

So far no luck. Any help appreciated.

Gordon

----- Original Message ----- 

From: "SRY" <southernry_n@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, July 25, 2007 11:30 PM
Subject: [Homebrew_PCBs] Help finding transformer for r.s.u.


> I've been meaning to build a resistance solder unit. I went to the
> local RS yesterday to see what types of transformers they had. They
> didn't have anything close to what I hoped to find. Not deterred I
> went to an electronics store. There sure were a number of large flat
> screen tvs in for repair! I gave the tech what I hoped would be an
> easy part to provide. Nope, he said,  try Jameco on line. So I came
> home and I did. Either I'm not sure what to put in the filter or I'm
> looking for an oddity.

RS used to sell a transformer kit with just the primary, so one could put 
one's own secondary on it. I used one once for a special low voltage I 
needed. One of those would be ideal, wound with really thick wire for the 
desired currrent. They might still sell them.

http://rswww.com

Leon

try Ebay. 


       
---------------------------------
Yahoo! oneSearch: Finally,  mobile search that gives answers, not web links. 

[Non-text portions of this message have been removed]

In article <f88iu9+ro6j@...>,
   SRY <southernry_n@...> wrote:
> For the curious here are a couple of links:

> http://www.girr.org/girr/tips/tips1/solderer.pdf

Hmmm, sounds ok for soldering tinplate together but I wouldn't use one for
delicate electronic components. I'll stick to a proper temperature
controlled iron or hot-air unit thank you.

Salvage a microwave oven transformer and remove the HV secondary.

Wind your own high amperage low voltage secondary to the specs your need 
/ work.

The web will have many sites that show how to do this for resistance 
welding batteries etc.

Hugh


SRY wrote:

>I've been meaning to build a resistance solder unit. I went to the
>local RS yesterday to see what types of transformers they had. They
>didn't have anything close to what I hoped to find. Not deterred I
>went to an electronics store. There sure were a number of large flat
>screen tvs in for repair! I gave the tech what I hoped would be an
>easy part to provide. Nope, he said,  try Jameco on line. So I came
>home and I did. Either I'm not sure what to put in the filter or I'm
>looking for an oddity.
>
>I'm trying to build a resistance solder unit.
>
>I've searched on-line.
>
>For the curious here are a couple of links:
>
>http://www.girr.org/girr/tips/tips1/solderer.pdf
>
>But this one uses a battery charger. I was hoping for something a bit
>smaller and more home-brew.
>
>This is more like what I was hoping to find but a bit pricey:
>
>http://www.istnet.net.au/~wamrc/res_solder/index.html
>
>
>Yeah, I also went out to the Train Index. I have the Mainline Modeler
>magazine. That's what started this train of thought.
>
>And there is this reference too:
>http://www.trainweb.org/bristol-s-gauge/Projects/rsu.html
>
>So what the heck am I looking for???
>
>I thought I knew!
>
>One article suggests a transformer that takes house current and on the
>secondary posts gives 6-8 volts AC at 3 Amps. That's what I was asking
>for at the local stores.
>
>Another articles says I need a filament transformer that provides less
>than 7 volts at 6 or more AMPS.
>
>So far no luck. Any help appreciated.
>
>Gordon
>
>
>
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBs
>
>If Files or Photos are running short of space, post them here:
>http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
>Yahoo! Groups Links
>
>
>
>
>  
>

Gordon
   I have had some luck using old soldering 'guns' as a transformer for a
RSU.
Remove the tip and attach the wires to hand piece and ground to the two rods
that would hold the tip.
If you have too much current try the lamp dimmer on the AC input.

Old guns of 100 - 250 watts can be found at garage sales and hamfest for a
few dollars.

John


On 7/25/07, SRY <southernry_n@...> wrote:
>
>   I've been meaning to build a resistance solder unit. I went to the
> local RS yesterday to see what types of transformers they had. They
> didn't have anything close to what I hoped to find. Not deterred I
> went to an electronics store. There sure were a number of large flat
> screen tvs in for repair! I gave the tech what I hoped would be an
> easy part to provide. Nope, he said, try Jameco on line. So I came
> home and I did. Either I'm not sure what to put in the filter or I'm
> looking for an oddity.
>
> I'm trying to build a resistance solder unit.
> Gordon
>
>


-- 
John D Young
WA8KNE
ETC USN retired


[Non-text portions of this message have been removed]

> secondary posts gives 6-8 volts AC at 3 Amps. That's what I was 
asking

Try looking at the hammond line @ hammondmfg.com look under classic 
tube transformers. They have specific filament xfers in the 3-8v @ up 
to 10amps. 

That or find any old peice of electronics that use vacuum tubes, the 
2ndaries always include a 6.3v filament winding capable of a couple of 
amps. 

If you decide to buy try angelainstruments.com, they have the best 
prices on hammond xfers Ive seen over the last 10 years.

GL wayne

> secondary posts gives 6-8 volts AC at 3 Amps. That's what I was 
asking

Try looking at the hammond line @ hammondmfg.com look under classic 
tube transformers. They have specific filament xfers in the 3-8v @ up 
to 10amps. 

That or find any old peice of electronics that use vacuum tubes, the 
2ndaries always include a 6.3v filament winding capable of a couple of 
amps. 

If you decide to buy try angelainstruments.com, they have the best 
prices on hammond xfers Ive seen over the last 10 years.

GL wayne

--- SRY <southernry_n@...> wrote:


> I'm trying to build a resistance solder unit.

> http://www.girr.org/girr/tips/tips1/solderer.pdf
> 
> But this one uses a battery charger. I was hoping for something 
> a bit smaller and more home-brew.

But you're not going to find much cheaper, or easier to 
build around.  You can buy chargers like these brand new
for ~$20-$30, and it comes in a nice metal box with a line
cord, switch and current meter.  You could readily modify
it for a footswitch and there's likely room for a dimmer
or ballast for current control inside.  Volt amps is volt amps,
for a given power the transformer is going to weigh a given
amount, so I'm not sure how much smaller you expect this 
to get.  By using a charger you get the housing, cords and 
controls built in for you, so it doesn't get any easier than
that.