Monday, June 16, 2008

Week 1 recap

Great initial meeting, thanks to all for your patience and participation! We got thru some initial soldering practice (making up some test clips that we'll use for the rest of the sessions), and the Victorian Synth project.

Soldering: everyone seemed to get the hang of things right away. The basics again:
  • use a small (25-40 watt) soldering iron designed for electronics
  • use small-diameter rosin-core "60/40" solder, not acid core.
  • keep your soldering iron tip clean by wiping on a damp cloth or sponge
  • make sure the wires/components are clean--no corrosion, insulation, oil etc.
  • heat the joint and apply the solder to the hot wires, not the iron
  • apply enough heat so the solder "flows" into the joint; avoid cold solder joints where the solder just forms a little ball sitting on top of the joint
There's tons of good tutorials on the web with lots more detailed advice: here's one from Curious Inventor, or google for more. We'll practice on some scrap printed circuit boards next week.

Victorian Synth: Again, everyone seemed to get it... I'll try and post the recording later this week. masami akita is jealous already

Schematics: I also wanted to post the intro to schematics that I scrawled out on the pad. As said, schematics are the road maps that represent electrical circuits, and one of our goals is to get everyone familiar w/ schematic basics so you can build designs you find in books or on the net. Here are the symbols used for our first project:

Every electronics component has its own symbol; and then lines between them that represent the wires connection them together.

In this project, the "switch" was the bits of foil we put in the speaker cone--when they touch, they close the circuit and conduct electricity; when they jump apart (as a result of the speaker spazzing out) they open and stop conduction... so the schemo for the first version looks like this:

That dotted line represents the mechanical connection between the speaker and the switch, and that's what creates the "feedback loop" where the speaker turns itself an and off to produce sound. the tone (or pitch, how fast the speaker cycles on/off) is determined by that mechanical connection...

When we complicated that w/ the 2-speaker version, we just took 2 synths and connected them together. in this case, we connected the switches and speakers in series (meaning one after the other)... in that configuration, both switches needed to close (foil in both speakers touching/conducting) in order for the circuit to be closed and the speakers to jerk.

As simple as that is, it's how most projects work... taking smaller building-block circuits and connecting 'em together to make something more complicated.

Anyway, here's a couple more symbols we'll use next week:

See you Saturday!

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