Nuts and Volts

PICAXE PRIMER

its jaws in a horizontal position about one inch above your work surface; a small block of wood about the size of a small breadboard; two pairs of tweezers (one straight locking and one non-locking, either bent or straight); a straight dental pick or something small and reasonably pointed (even a toothpick is fine); the prepared strip board; and the SMD to be soldered.

2. Pick up the strip board, hold it horizontally in your non-dominant hand, and use the pair of non-locking tweezers (in your dominant hand) to pick up and position the SMD on top of the board as accurately as you can. Don’t worry about perfection at this point; we’ll adjust the final position shortly.

3. Set down the non-locking tweezers and pick up the locking tweezers. Press them open, and then use them to “pinch” the SMD against the strip board. Refer to Figure 6.

4. Set down the non-locking tweezers and insert the back end of the locking tweezers — which are still “pinching” the strip board and SMD together — into the jaw of the helping hand.

5. Place the small block of wood under the strip board, and then lower the tweezer so that the strip board is resting on the wood. Check out the photo in Figure 7 (which I forgot to take until I was finished with the entire board!).

6. Starting with the easiest pin to reach, position your hot soldering iron so that the tip is touching both the end of the pin and the trace.

7. When the junction is hot enough — using the smallest amount of solder you can — solder the pin to the trace.

8. Solder the remaining pins in the same manner. Figure 8 is a photo of my strip board after the SOT-223 was soldered in place. As you can see, I used too much solder on the tab and on the middle pin on the right. However, the circuit would still be perfectly functional.