Free-form Assembly

The intermittent solar motor circuit is simple enough that it can be soldered together without a PC board, in a free-form, somewhat random rat's-nest looking way. Here is how it is done, step-by-step.

We start with the TC54 integrated circuit. Here we show it with the flat side up. This means the right pin is ground, the middle pin is positive, and the left pin is the output.

Next we solder the 1n914 diode to the ground pin of the TC54. We keep the black band facing downward. This means we are connecting the anode to the ground pin.

Next we solder the small capacitor between the ground and positive pints of the TC54. The capacitor has a positive lead and a negative lead, so you must solder the negative capacitor lead to the ground pin of the TC54, and the positive capacitor lead to the middle pin of the TC54.

Now we solder the base of the BC337 transistor (the middle lead) to the output pin (left lead) of the TC54. Then we solder the emitter of the BC337 to the cathode of the 1n914 diode.

We can now solder the solar cell and the large capacitor to the ground (right pin of the TC54) and the positive (middle pin of the TC54). Both the solar cell and the capacitor have positive and negative leads -- make sure you connect the negative sides of both of them to ground, and the positive sides to the middle pin of the TC54.

The last step is to solder the motor to the collector of the BC337 transistor (the left pin, the only one we haven't used yet) and the positive (middle pin of the TC54) lead.

Below is a video of a sculpture that uses the circuit we just built (the exact one, not just one like it). The solar cell and motor are glued to a loop of steel wire, and the circuit hangs between them. The motor spins a fine nylon monofilament that holds up the three loops of foam that are glued together.

As the motor occasionally spins, it winds up the thread, since it can't spin the big foam loops all by itself. The thread then slowly unwinds as the loops start to gently rotate. This way, the motor can make the sculpture move slowly, without any noisy gears. Without the intermittent circuit, the motor would not move at all, unless the solar cell was in strong direct sunlight. With the circuit, normal room lighting makes the sculpture move at a sedate pace, as you can see in the video.

The result is a rather nice optical illusion.