Solderless Breadboard Guts

Breadboard polymer form and springs - note how the springs tightly insert into the board's polymer form. In the middle is a pile of springs, each will hold 5 wires in this breadboard version. At bottom is a disassembled power bus. This is one long conductive metal strip of springs.

SOLDERLESS
BREADBOARD GUTS

We took apart a solderless breadboard and removed the guts inside to see how it works. Don't worry, the breadboard was already defective and only the end hole strip where one bus bar was missing. The photos tell all.

The link shows how to measure the extra capacitance on the breadboard. Measuring resistance is more simple - just measure ohms from the two farthest holes.


Pop open a solderless breadboard to see what's under the hood. With some care, the top lifts up while a good number of springs remain stuck to the sticky backing. A wire cable is shown for comparison. Note some of the green faced sticky backing peeled away.

"When building an experiment on a solder-less breadboard, you add the small (stray) capacitor between adjacent rows of connection points to the circuit. This is because the way the solder-less breadboard is built, it has rows of metal connection strips laid side by side (0.1 inch apart) separated by plastic dividers. Because the strips are fairly long and they are in parallel, they have a significant capacitance between them."(1)

"Due to large stray capacitance (from 2-25 pF per contact point), high inductance of some connections and a relatively high and not very reproducible contact resistance, solderless breadboards are limited to operation at relatively low frequencies, usually less than 10 MHz, depending on the nature of the circuit. The relatively high contact resistance can already be a problem for some DC and very low frequency circuits. Solderless breadboards are further limited by their voltage and current ratings."(2)

Showing two decoupling capacitors

The extra capacitance from the layered bus bars may actually contribute more effectively to the Propeller chip's required decoupling capacitance. There are physically four pin layers on the breadboard at decoupling capacitor's position that may yield up to 100 pf. However, the recommended decoupling capacitance for each side of the Propeller DIP chip is 100 nf so decoupling capacitors are still needed. (0.1 uF = 100,000 pF)




SOURCES
(1) http://wiki.analog.com/university/courses/electronics/electronics-lab-breadboard-coupling
(2) http://en.wikipedia.org/wiki/Breadboard
(3) http://forums.parallax.com/showthread.php/124495-Fill-the-Big-Brain/page62

Air Travel Chain Effect

AIR TRAVEL CHAIN EFFECT - Stay Safe & Protect Electronics

EVA Airline Technicians inspect wheels and tires before departure. EVA Air is viewed by many as one of the safest and most convenient ways to travel. In a hot climate, aircraft air conditioning is extremely important as well as careful luggage handling and safe flight history.

A chain is only as strong as its weakest link. How to stay safe and protect electronics during air travel.

Big Brain EXOskeleton As shown in the photo below, the Big Brain Exoskeleton incurred damage during the recent shipment out of China, even though it was carefully wrapped in surrounding blankets. It's always a little confusing - are you on China Air or Air China? The metal brass spacer holding the LCD broke off at the thread position (see top right). The nut with the broken threads is seen just above the top left corner of the white solderless breadboard. Normally such precarious position on the EXO would have a remedy modification for strengthening the mount. However in this case, we like the EXO idea so much, it will be a simple matter to just replace the brass spacer. What's so desirable about the EXO design? Even though mounting wires and components on the outside of the Big Brain machine can compromise its function during rough handling, the benefits far outweigh the disadvantages. The ease and convenience of wiring, rewiring, examination, inspection, modifications, and upgrades are super easy. Lighting is also at a premium and photographing the layout is easy. For future shipping, remove the LCDs.

OOPS - Big Brain EXOskeleton Broken in luggage

Parallax Penguin Robot

Penguin robots are very strong and sturdy, built with nylon and machined metal. However, Chinese luggage handlers maintain their reputation to be stronger. It's estimated this luggage was dropped from a height of 12 feet. The majority of the shipped assembled penguins broke at the legs linkage connecting to the servo. Most had the white nylon servo linkage (servo horn) that connects the legs linkage to NARO servo broken. This appears to be the weakest link in the Penguin robot chain. For future shipping, remove the servo horns.

Parallax Toddler Robot

The weakest link in the Toddler robot chain is the underside stride linkage. For future shipping, remove the stride servo horn.

Solderless Breadboards

Nylon polymer solderless breadboards, which were wired with Parallax Propeller chips, completely survived the rough handling. They were wrapped in towels. A photographic schematic was first created and interconnecting wires were removed. These boards easily stack during shipping.