self test warning buzzer

For something like this (low freqency/DC, no RF), a piece of "perfboard" (a predrilled sheet of insulated board) is perfect. Stick parts in on one side, make your wiring connections on the other side. You can get it at Radio Shack.

A lot of the companies that make printed circuit boards have frre version which are limited in scope. DIPTRACE is one of them. KiCAD is open source, but has a high learning curve. They all do. Then there are "propretarty" websites that use their own program. Their program is directly able to calculate the price of the board. You have to use their shop to have the board made. I had some brief training in the tape ERA, where boards were typically done 4X their normal size.

The technologies available to hobyists include:
1. Direct resist - Use pen and draw circuit. (works for really simple circuits)
2. UV positive or negative exposure to sensitized boards.
3. Direct toner transfer (Uses a laser printer and laminator)
4. There is some experimentation going on to use ink jet technology. Someone makes a carrier that can fit in the CD slot of an unmodified ink jet printer and can print a pattern. Epson has so far one.
5. Others have modified Epson printers and made the carrier bigger. They also simulate the sensors.
6. MISPRO ink works in Epson Printers. Now there are experiments going on with NGen Inks which is VERY expensive.

For surface mount technology, a stencil is purchased or made so that solder paste can be placed on the board. A toaster oven is typically modified to have the right temperature-time profile.

Cool stuff.

I do a lot of small one-off projects on these types of perf-boards: Dual Mini Board with 213 Holes - RadioShack.com Mount all the components on the other (non-copper) side with their leads through the holes. Solder the leads to the pads and trim off the excess. Do point-to-point wiring between the pads.

Ken

That's one way to do it.

I've never used the type of perfboard which has copper pads; I just use regular unclad board, stick the components in one side, then use my own perverted version of wire-wrap on the other side. I use telephone wire (small gauge solid insulated wire), wrap it around the component lead and solder it. I find I can make most connections without even using wire: simply wrapping one component lead around another.

This even works well with IC pins, provided you're careful soldering and don't let it get overheated. It's a little more work, but the results are neat and functional.

Regarding having boards etched: forget about it, unless you're planning on going into production. In which case, don't try to DIY it. There are board houses that can make much better boards than you can for relatively cheap.

The only time you really need a real etched PCB is with RF (high-frequency) circuits. Or if you're going to use surface-mount components. Or if you need more than a single-sided board.

I do all the non-power wiring with 30Ga Kynar wire-wrap wire. I strip it bare if I don't need to cross any other wires. I strip 1/16" of each end if I need to cross over other conductors. Telephone wire for low power and ground traces. I usually use ExpressPCB to do a schematics. I then use the PCB program to layout a PCB on 0.1" grid to match the perf-board. I did have to add some 0.1" pitch components to the library. ExpressPCB lets you verify the trace connections on the PCB layout with the schematic. Any traces that would cross on the bottom of a PCB are moved to the top layer. That saves me a lot of grief. If I do want an official PCB, it's all done.

Ken