Simple PhotoCell Timing System
(S.P.T.S.)
SOLDERING TIPS

(c) Bryan Brown & Art McEwen 1997-1999
All rights reserved, not to be copied without permission.


I Have Seen The Light

I finally figured out how to solder electronic components. Over the years, I have left a trail of destroyed and melted components, much to the delight of the clerks at my local electronics supply shop. The secret is in the soldering tool. For years I have been using a soldering gun, with its pistol grip and searchlight illumination. It's great for joining two wires but you cannot control the heat and I ended up melting everything in site. Duh! This also explains my fear and paranoia about soldering PhotoCells.

Well, we can all relax now because I finally learned how to do it right. I finally went out and bought the right tool for the job, a soldering pencil. It cost $12.99 CDN for a 5 piece tool set at Radio Shack (Part Number 64-2802). It is a 30 watt pencil and its great because it has just the right amount of heat.

A simple 5 piece soldering pencil tool kit available at most electronic supply stores for less than $10.00 US


Soldering a DB25 connector (like Radio Shack's 276-1536 for $3.99 CDN) was a piece of cake. Here's the trick.
  1. Let the pencil heat up to it's normal operating temperature.
  2. A new iron/pencil needs to be coated ("tinned") with solder first before using.
  3. Keep the point clean, wipe off excess solder occaisionally with a rag.
  4. Clamp on a "Heat Sink" between the delicate electronic component itself and where you are soldering. This prevents heat from running up the wire and creating no end of havoc. A heat sink came with the pencil set but you can also use pliers or vice grips.
  5. Dab the wire you intend to solder in flux to improve the flow of the melted solder then heat the wire with the pencil and put on a healthy amount of solder. Not a huge gob of it, just a dab.
  6. The solder will solidify on the wire as the heat is taken away. Now move the wire into position butted up against yur target.
  7. Then with the pencil, just give the end of the wire a very brief touch, almost a zap. The pencil should melt the solder directly to the component. The solder should set right away and you can give the wire a gentle tug to ensure that it is indeed firmly attached.
  8. Don't hold the pencil on the component for any length of time. Heat is the enemy.


This technique worked magnificently on the DB25 connector where the pins are so close together that you can't even get a heat sink in place. I don't want you to know how many DB25 connectors I've mangled with the gun.

Remember, too much heat destroys. Not enough heat and you get another chance.

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