soldering a thick wire to to-204 package

i have a darlington PNP transistor MJ11033. i have to draw atleast 30 Amps from it. problem is how to solder thick wire to this transistor. There are bases available in the market but they dosen't seem to fit these in because its pins are thicker than a transistor like 2n3055.

You can wrap a thin bare or tinned copper wire around transistor pin and cable to fix the latter. Then solder it regularly. You can inspect commercial available instruments, e.g. DC/DC inverters, how they do it.

Sockets for this case style are available, but possibly not in your area. Voltage drops are lower with soldered connection anyway.

The important thing is to have a soldering iron with sufficient power and a large bit, so the joint can be made rapidly. One method:- Tin end of lead for about about 15mm. Form around transistor lead, cutting off any excess. Solder with a little excess of solder on the irons bit. N.B. when the solder melts the lead will come loose and may spring off if it is not held down or formed properly. Practise on something less valuable first!
Frank

Hello there.

My question may be freak, but I'm really interested in answer.

In my country (I'm from Russia) electronics hobby took roots very long time ago and during Soviet period it was thoroughly supported by government. So there are some traditions (traditional techniques) which were established in last hundred years of electronics hobby in my country.

The thing is my fellow citizen almost never bring solder directly to the wire by hand (or another detail) while tinning. We usually take some solder with the soldering iron tip (not just tin the tip, but actually load tip with necessary amount of solder) and touch with the tip detail that is to be tinned. Then we slightly move tip along the detail, helping solder to flow. The same thing with PCBs: we usually bring solder to the joint with the tip. This method has obvious advantages:
- you don't need "helping hand" device;
- it takes less time as you don't need to heat the detail before applying solder: detail gets warm enough during as you apply solder and move tip along the detail;
- as you don't need to heat detail before making joint, you have less chances to overheat the detail. That may be not very important while soldering wires, but that gets important if you make point-to-point circuitry, which contains semiconductor elements, which can be overheated easily.

So, once I decided to watch YouTube and know how you, western guys, make soldering. I was very surprised to see that technique when solder is applied directly to the joint by hand (or with helping device) is a sort of "orthodox" among electronics hobbyists and professionals.
I've watched about 30 vids about soldering techiques. 28 of them demonstrated "direct applying" technique and only 2 of them taught viewer to bring solder with the tip.

"Direct applying" example:
https://www.youtube.com/watch?v=L61LJcz7H6g Look at this man (watch from 6:10). Joint he made is awful! He was trying to heat up the wire for more than a minute. I think it's just fail.

"Loading the tip" example:
https://www.youtube.com/watch?v=3Z8CzB4BYJAWatch from 2:10. Soldering is instant.

So my questions are:
1. Why "direct applying" technique is so popular?
2. Do you ever bring solder to the joint/wire with the tip? Or you always use "direct applying" technique?

I'll be grateful for your answers.

P.S. I've tried "direct applying" technique in my home laboratory and I have to admit it's not bad, but I still don't think it has serious advantages.

P.P.S. https://cxem.net/beginner/beginner85.php - that's how we usually make soldering. It's in Russian, but I think video is enough. Watch from 16:30.

I think it has more to do with the type of flux than the soldering technique. I'm niot sure what is/was available in Russia but most US/W. European solders have flux channels inside the solder. The flux is a heat activated reducing agent to remove oxygen (de-oxidize) the wires at being soldered but it has a very short lifetime before 'burning' away. I'm not a chemist but I would guess this is atmospheric oxygen being reduced. If applied directly to the joint it has time to react with the connections and ensure a good joint but if applied to the tip, some will have burned before reaching the point where it is needed. There is also the safety aspect, carrying molten metal risks drips, splashes and burns!

Brian.

If applied directly to the joint it has time to react with the connections and ensure a good joint but if applied to the tip, some will have burned before reaching the point where it is needed.

Click to expand...

I guessed the reason is interconnected with flux and it's ability to burn out. But your argument is valid only if we're talking about soldering without using additional flux (if we depend only on flux, placed in core of solder).

Applying some good flux onto the surface which is to be tinned (or to the PCB pad), we don't depend on core flux anymore. Additional flux won't burn too quickly and bringing solder with the tip becomes quite proper way of soldering.

Risk of oveheating is not higher than with direct applying technique: bringing flux with tip provides good heating square, detail becomes heated instantly and you don't need to hold tip near detail for too long. Just like at the second vid.

I'm niot sure what is/was available in Russia but most US/W. European solders have flux channels inside the solder.

Click to expand...

Indeed, in USSR was no flux-core solder. Solder was shaped in rods about 8mm dia, so we had no variants except loading tip with solder. Pure rosin was used as flux. But nowadays we have flux-cored thin solder and very different fluxes. I use flux-cored solder and modern flux, but nevertheless I consider bringing solder with a tip as a quite proper way of soldering.

- - - Updated - - -

By the way, some western guys would agree with my method:

https://cs.trains.com/mrr/f/88/p/99471/1158695.aspx#1158695Read 2nd post