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I picked up my first "from-scratch" DIY electronics project in a long time, building a 2-tone door bell on stripboard with a basic 555 circuit.

For the most part everything went well. I assembled the circuit and measured up before going out and getting a snug fitting plastic enclosure (since it will be mounted close to the door).

I made one vital mistake, I forgot to include the 555 IC in my measurements, which is now protruding from the IC holder I soldered in - and now the 9v battery is poking out of the enclosure and blocking the lid!

I feel I have three options:

  1. Meticulously unsolder the IC holder and solder the 555 directly to the stripboard
  2. Run the 9v battery clip outside the enclosure and strap the battery to the outside of the box
  3. Re-measure and buy a slightly larger enclosure

I'm not experienced at soldering; my current efforts have been reasonably neat but the components have had to cope with some excess heat as I occasionally fumbled with the solder. I'm very tempted to give the resoldering a go, but does anyone have some advice on how to keep the component cool while I solder the pins? Are there any other things I should watch out for when soldering an IC without a holder?

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  • \$\begingroup\$ As a kludge, you can probably bend the 555 pins up and solder it to the underside! \$\endgroup\$ – RedGrittyBrick Jun 12 '13 at 9:43
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    \$\begingroup\$ Buy a bigger box - its not worth the heartache of trying to desolder, resolder and then fault find a bridge or have to replace components. \$\endgroup\$ – JIm Dearden Jun 12 '13 at 10:02
  • \$\begingroup\$ @JImDearden a good point. I'll certainly give it some thought before jumping in with my soldering iron, these boxes are cheap after all. \$\endgroup\$ – seanhodges Jun 12 '13 at 14:14
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For the IC holder (called an IC socket normally) the most difficult part will be desoldering it without some some form of solder sucker. Personally I'd cut away the plastic section with side-cutters and then remove the pins one by one considering you don't want the socket. Then either user a small hand-held solder sucker (they only cost a few dollars) or if you don't have one maybe push through a piece of wire while applying heat to clear the hole of remaining solder.

For soldering the IC directly it's easy to be paranoid but DIP packages are often wave soldered which involves dipping in solder and making every connection at once and the pins themselves will dissipate a lot of heat before reaching the die of the chip. Just to be a bit extra cautious as you improve your soldering technique maybe just wait 15 seconds or so between each pin to give it a while to cool down. You should find the top of the chip will barely become warm, it if is just wait a while until it cools down.

I suspect the trickiest thing is likely to be removing the socket without tearing off the tracks on the stripboard. That's why destroying the socket and removing pin by pin is probably easiest.

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  • \$\begingroup\$ Thanks for the detailed answer PeterJ. I'll shift my attention to the removal of the IC socket first. I'll practice on another socket and piece of scrap board first, I would rather waste a couple of IC sockets through practice than risk a torn track on my project! \$\endgroup\$ – seanhodges Jun 12 '13 at 13:31

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