THE MAGAZINE FOR COMPUTER APPLICATIONS
Circuit Cellar Online offers articles illustrating creative solutions
and unique applications through complete projects, practical
tutorials, and useful design techniques.

BREADBOARDING

by Stuart Ball

Start ý Grounding ý Placing Copper Strips ý Power Wiring and Supply Bypassing ý Lead Wiring ý Test Points ý Surface-Mount Parts ý Other Tips ý Putting It All Together ý Other Techniques ý Sources and PDF

LEAD WIRING

I like to mount the ICs with a couple rows of holes between them (see Figure 3). The signal wires are then run on top of the board using 30-gauge wire-wrap wire. The wire is passed through the holes next to the IC or component leads, and about 0.25ý is stripped and wrapped around the lead. This is then soldered. The holes in most perfboards are large enough to accommodate two wires.

Figure 3ýInsulated wires are run through the board, stripped, and soldered to the component leads.

The wires are run in the channels between the ICs. Placing the wires on the top of the board in this way reduces the chance of accidentally breaking wires off the board, something that is always a problem with point-to-point wires routed on the bottom of the board. For areas where a lot of wires have to be run (such as a microprocessor data/address bus), I like to leave three or four rows of holes between the ICs.

There is often a temptation for new builders to pull the wires tight when making these connections. It is better to leave a little slack in the wires to prevent wire breakage and avoid warping the board. Itýs really frustrating to check out everything then have it quit working because you broke a too-tight wire when you bolted the board into the case.

Itýs a good idea to socket the ICs on any prototype. The cost of the sockets raises the cost of the prototype somewhat, but sockets permit you to solder the parts without danger of damaging the ICs and then plug the ICs in when youýre done.

PREVIOUS • NEXT