Solderless breadboard capacitance

Beware of sweeping generalities. On a certain level, electronics is an exercise in statistics. As stated earlier, in another thread, the capacitance between the adjacent contacts of one of my own solderless breadboards is 31 pF. A Keysight U1733C handheld LCR meter was used to take this measurement.

Danke,

Such a great difference needs explaining. The breadboard I measured this on is an 'Ormatu'. It has two rows of 48 strips with 5 holes each. Full-length strips run along the top and bottom. I measured between a pair of adjacent unoccupied 5-hole strips.

My C-meter rejects probe and cabling capacitance. It only sees capacitance from one probe tip to the other. I can handle and move test leads around with impunity without upsetting the offset. I suspect such is not the case for the Keysight? Did you try measuring fixed known capacitors in the same value range with it?

Jeroen Belleman

Those plastic things are dreadful, about the only reason to have a stock of thru-hole parts around.

If you hook a scope probe or an alligator clip lead to one of those things, don't they pull the parts out, or short things? I've never used one.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Sure, they're dreadful, but they're just the thing if you want to quickly wire up a few things with lots of pins on

I wired up an Arduino Nano to a little module with an AD9851 DDS to to familiarize myself with its quirks. It was quick and easy. Quieter than dremeling!

Amazon sells breadboards for $8 qty 4.

Jeroen Belleman

But interesting chips don't come in DIP packages. We rarely use leaded parts any more.

Dremeling isn't very noisy, is fast, and lets me use surfmount parts, controls impedances, gives me a good ground plane, makes everything visible, and lets me keep a circuit for future use.

Anything serious gets a PCB layout and a multilayer PC board. I'm not very good at dremeling BGAs.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

I have one that I've never used (the kids used it a couple of times, years ago). IIRC it measured about 2.5 pF between adjacent rows, using a 3-wire capacitance meter (Boonton 72C).

{From my draft fourth edition, expected sometime in the 25th century:

\subsection{White solderless breadboards} These superficially attractive chunks of white nylon allow you to shove component leads right into an array of socket pins, which are interconnected in rows. A simple circuit can be wired up without using any solder at all---{}look, my PIC can blink a LED!

And it can, provided the plastic thing is new. Then of course somebody plugs in a resistor from an old reel without removing the residual adhesive, and two of the holes become flaky forever. Then the next resistor is maybe oversize, and bends the crappy metal fingers apart, and the one after that is corroded, and leaves semi-insulating dust all over the place\ldots Not to mention a couple of picofarads of capacitance between adjacent rows and many tens of nanohenries in series with all the nastily daisy-chained grounds, so that you can't get decent bypassing no matter what you do.

And then there's leakage due to the low-grade hygroscopic plastic, RF pickup from everywhere due to no ground plane\ldots{}. } (Followed by a paean to the glories of dead bug construction.) ;)

Cheers

Phil Hobbs

My own itty bitty breadboards became bone pile potpourri decades ago. They're too tiny. You start assembling a prototype only to run out of real estate. Then you must painstakingly begin anew with a larger breadboard. My prototypes already tend to require too many painful restarts due to lessons learned along the way. A larger breadboard eliminates at least one potential restart. Long story short, my only media these days is big, bodacious breadboards such as an EIC-108 or a 3720-pt FCB*USA*.

EIC-108 3220 Tie-point Specifications Square hole Metal plate 240x210x0.8mm Board 184.4x190x8.5mm ABS plastic with color printed 4 Terminal strips, 2520 tie-point 7 Distribution strip, 700 tie-point 4 Binding posts 5 Cushions The Keysight U1733C's a very versitile, venerable device. It does indeed correctly measure a 1 pF ceramic. With U1733C's frequency set to 100 or 120 Hz it measures my breadboard's parasitic capacitance at 31 pF. At higher frequencies it detects 2-4 pF.

A big, bodacious breadboard is my favorite for fritzing and ferreting out digital secrets. But it's probably going to let you down if you try to assemble a YIG oscillator from components on it. As pointed out elsewhere, we now live in a SMT world. So double side universal PCBs are my main media. Unless something more exotic requires carving up copper or a custom PCB.

Danke,

This is my current rats-nest proto-plaything...

Any guesses what it does?

(And yes, I need to get the duster out :)

I use veroboard for many projects

There are cheaper and better low capacitance breadboard alternatives:

I have about 5 of those solderless breadboards. I bought them at a garage sale about 30 years ago, and never used any of them. They don't work for high currents, RF over about 1 MHz, low noise levels, high temperatures, mechanical stability, uses stranded wires, or requires non-intermittent component connections.

However, the uglier the breadboard, the better it works. I guess that the solderless breadboards produce the required ugly breadboards.

atleast $200 of those is for the 3M sticker

I think most use them not with parts, except for a few passives, but with modules

We use to use the AD DDS chips as the internal trigger source for pulse and delay generators. But they are expensive, complex, klunky. The interface is either slow SPI or a zillion pins. We do our own

AD9851 is a narrow-pitch SSOP28. How do you put that on a plastic breadboard?

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

I suspect that you never etched a 4-layer board with plated vias. Or soldered a BGA to a home-made board.

PCBs are almost a hundred years old and they don't look like being replaced soon.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Disagree. Beautiful electronics works better than ugly. There are real reasons.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

I beg to differ. Ugly breadboards, where components are soldered to a random piece of G10/FR4, offer two important advantages over aesthetically pleasing drilled and etched PCB's.

Better grounding. The ground plane is a continuous sheet of copper and is not butchered into a collection of grounded islands.

Ugly breadboards are typically built in three dimensions while those more closely resembling the final PCB offer only two dimensions. The

Ugly breadboards are a good way to discourage management from stealing the breadboard and shipping it to a customer or industry pundit as a finished product. Same with trade show prototypes.

That's the reason then. A frequency of 120Hz is no good for measuring pF capacitances.

Jeroen Belleman

A proto on double-sided copperclad has a nice ground plane on the back side. One can use suface-mount parts and carve controlled-impedance traces. Everything is surface-mount nowadays.

I own the company and I'm unmanagable so don't worry about management.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Interesting. Thank you. There's also another potential usage error. The capacitance table shown on page 3 of the U1733C data sheet:

leads me to believe a 1 pF measurement is also out of range.

Danke,