View source for User:Woozle/notes for electronic learning kit

[[Category:Woozle crafts]]This page is for taking notes as I put together an electronic learning kit as a birthday present for [[Zander]]'s friend Henry.
==Why==
Henry is apparently interested in this sort of thing (as is Zander), but it has become maddeningly difficult to find any kits in the stores anymore; everything is even more preassembled than it was back in the 1970s (and it was already bad enough then).

What I want to create is a collection of off-the-shelf standard components (nothing specialized, so any learning doesn't depend on particular models or manufacturers) which can be used to quickly create a number of projects which a pre-teen-age kid would be likely to find interesting -- mainly flashing lights and things that change when you flip a switch; basic electrical logic stuff. Along with that, there should be a page or two showing some example circuits (to give an idea of what is possible, and how to get started) and maybe a brief introduction to electrical theory (squeezed in where it won't feel like a lesson). All the informational stuff will be up on the web (on htyp.org), GPLed and available for anyone to use; if there's interest, I might buy the parts in bulk and resell them as a kit on vbz.net, too.

Maybe later I'll create other kits based on transistors or ICs, but relays and incandescent bulbs (with voltage requirements conveniently matched to available battery-pack sizes) are what I know best, so I'm starting with that.
==Parts list==
This is what we were able to find in about 20 minutes of going through the parts drawers at Radio Shack. (They aren't hanging out on pegs anymore the way they used to be, but actually the drawers seem to make it easier to find stuff, so I'm not complaining... except that they no longer seem to carry level-sensors or magnetic sensors. Poo.)
* 270-0391A $1.69 "AA" Battery holder for 4 batteries (6 volts)
* 272-0802 $4.29 assorted electrolytic capacitors (looks like about 18 of them; back of the pkg says 20)
* {{yp|272-1098}} $1.99 miniature 6v lamps (1 each: red, yellow, green)
* {{yp|275-0240}} $4.29 5VDC relay (ok up to 6.5 VDC according specs on back)
* {{yp|275-0702}} $3.49 auto flip-switch panel assembly
* 278-1156 $5.19 pkg of 10 test/jumper leads with alligator clips (2 each: black, green, red, white, yellow)
I got 2 each of the mini-lamps and the relay, and a spare set of alligator clips for Zander (so he could stop borrowing mine)3. There were also some extra parts I got for myself, in order to attach leads to the relays (which are breadboard-mountable):
* 276-1570A $6.99 wire-wrapping tool
* 278-503 $3.49 blue insulated wrapping wire (any color will do)
The total came to $42.89 before tax, or $27.22 without the wire-wrap stuff and the extra bag of alligator clips for Zander.
==Wire-wrapping the relays==
I decided that the leads on the relays were really a bit short for alligator clips, and that a good solution would be to wire-wrap on some leads for them.

<center><big>RAWWWRRRRR!!!!</big></center>
[[Image:Relay with wires wrapped.jpg|450px|center|RAWWWRRRRR!!!!]]

[[Image:Relay with wires wrapped - pair.silly.jpg|thumb|center|350px|A breeding pair! Oh '''NOES'''!!!!]]

[[Image:Relay with wires wrapped - jellyfish.jpg|thumb|center|250px|Jellyfish mode!]]
==Documentation==
* {{yp|Woozle's electronic learning kit No. 1 - sample circuits}}
* {{yp|Woozle's electronic learning kit No. 1 - parts and such}}