Using jumpers to quickly swap components

[HendriXML]

Hi,

Did a quick experiment on how to use jumpers to make resistors (or other components) swappable, to enhance the joy and speed of experimenting on a perfboard.
It needs a bit more spacing because of the 2x2 headers.
But compared against using crimped/soldered dupont connectors they are handier.

• Using the test perfboard you get a "third hand"
• No need to crimp
• Good orientation
• Spacing is accurate
• Easy to have different spacings
• Easy to swap
• Shorter “legs”
• More isolated

I measured the voltage drop of (2) it was 17.9 mV at 3.2A making a resistance of 5.6 mOhm.
The used wire in between dropped 0.9mV so it had a resistance of 0.3 mOhm.
Thus the jumper connections are about 5.3 mOhm.

Good enough for a lot of applications!

While soldering some care has to be taken not to solder to the header.
 

[magic]

Pro tip: check out SIL/SIP sockets.

[HendriXML]

They’re on order. Had previously only bought one strip. That one I used as a tiny breadboard  . Handy stuff.

Maybe I will do a comparision, but I don’t think the tick wire will fit 

[Ian.M]

You can also cut up turned pin IC sockets if you don't have any SIL turned pin socket strips handy.   For components with a similar lead diameter to the turned pin pin, if the lead is cut cleanly it will plug straight in.  If there is a moderate diameter mismatch, solder the lead into the socket side of another turned pin socket and use the pin side as a plug.

[T3sl4co1l]

IC sockets may be a bit too tight, in which case the next best (top best??) option would be Mill-Max headers/sockets, available in all sorts of sizes.  Pricey as frig though.

Plain rectangular spring contacts would be fine (how solderless breadboards do it), but they don't seem to be as available, with contacts sprung for small minimum diameter leads.  Regular 0.025" square pin header sockets are pretty wide open, not good for much besides square pins.

I've done it that way too, with a socket header in the board and components soldered to pin headers.  Not as freely pluggable as random proto-bin components (need to prepare a component+header assembly), but alright when you have just a few combinations to try.

Tim

[NorthGuy]

Looks like you're re-inventing solderless breadboards

[HendriXML]

But with the benifits of inhaling solder fumes 

[Audioguru]

Wait a minute! Why do you need to swap components?
Because you never learned how to simply calculate their values and you are using "trial and error" instead?

I never guess about component values, I calculate the values by reading the datasheet minimum and maximum spec's for an active device the components are used with. Then my circuits work perfectly without changing anything.

Oh yeah. I buy quality parts, not junk from "over there".

[HendriXML]

That’s cool. The way I “calculate” my fuses for instance is that I start with the lowest value one and then climbing up until the new one doesn’t blow any more. 

[Audioguru]

The way I “calculate” my fuses for instance is that I start with the lowest value one and then climbing up until the new one doesn’t blow any more. 

I hope you don't do the same with car tires and other car parts.

[HendriXML]

The way I “calculate” my fuses for instance is that I start with the lowest value one and then climbing up until the new one doesn’t blow any more. 

I hope you don't do the same with car tires and other car parts.

Lots of calculations, but gladly also a lot of testing is done when designing car tires. It’s hard to fully model the real world, you must agree on that. Experimenting and checking is as a method simply irreplaceable.

[james_s]

Wait a minute! Why do you need to swap components?
Because you never learned how to simply calculate their values and you are using "trial and error" instead?

I never guess about component values, I calculate the values by reading the datasheet minimum and maximum spec's for an active device the components are used with. Then my circuits work perfectly without changing anything.

Oh yeah. I buy quality parts, not junk from "over there".

I calculate to get a reasonable starting point but I often find that I need to tweak things a little in the real world to get some things working properly. Other times I'll be doing more of a seat of the pants thing and just experiment to see the effect of a particular component on the circuit. Being a very visual thinker I find that a lot more interesting than plugging numbers into an equation. Not everybody playing with electronics is a professional engineer and there's no reason to look down on them for that. You have a process that works for you, he has a process that works for him, so what?

I mean did you come here to help, or just to show off how smart you are?

[KL27x]

I spent a couple years making "useful stuff" like this. I think it's just a phase some of us go through. Prediction. In 2 years, you will be using mostly smd parts and swapping them out with a hot air station.

[HendriXML]

I spent a couple years making "useful stuff" like this. I think it's just a phase some of us go through. Prediction. In 2 years, you will be using mostly smd parts and swapping them out with a hot air station.

Just curious, but how does one prototype with smd parts without using designed pcb’s?

[Fire Doger]

I spent a couple years making "useful stuff" like this. I think it's just a phase some of us go through. Prediction. In 2 years, you will be using mostly smd parts and swapping them out with a hot air station.

Just curious, but how does one prototype with smd parts without using designed pcb’s?

They don't, they design PCBs *(Unless you mean prototyping something basic that can be calculated on the back of an envelope)
The question is what kind of pcbs

For simple layouts
They break it into small schematics according to functionality and build them individually for faster workflow, debugging etc...
If its simple (no tiny tracks, BGA etc) then probably you can do it on a diy pcb. If you got a set up for home pcds it will be very fast.
It takes me 1h to print it while doing something else at the same time.

For complex layouts (BGA - Multylayer)
You rely on datasheet, examples, appnotes, etc. Good EDA helps too.

Many times "calculating" may be much more expensive than building it.

Everyone at the end have to build it as final product. PCB is part of the circuit and interacts with it. (you can see it clearly when speed-voltage-current-temperature goes up)

Ending with many prototype pcbs is not unusual... The key is to minimise the number/cost of them.

[HendriXML]

I spent a couple years making "useful stuff" like this. I think it's just a phase some of us go through. Prediction. In 2 years, you will be using mostly smd parts and swapping them out with a hot air station.

Just curious, but how does one prototype with smd parts without using designed pcb’s?

They don't, they design PCBs *(Unless you mean prototyping something basic that can be calculated on the back of an envelope)
The question is what kind of pcbs

For simple layouts
They break it into small schematics according to functionality and build them individually for faster workflow, debugging etc...
If its simple (no tiny tracks, BGA etc) then probably you can do it on a diy pcb. If you got a set up for home pcds it will be very fast.
It takes me 1h to print it while doing something else at the same time.

For complex layouts (BGA - Multylayer)
You rely on datasheet, examples, appnotes, etc. Good EDA helps too.

Many times "calculating" may be much more expensive than building it.

Everyone at the end have to build it as final product. PCB is part of the circuit and interacts with it. (you can see it clearly when speed-voltage-current-temperature goes up)

Ending with many prototype pcbs is not unusual... The key is to minimise the number/cost of them.

Thanks. Making my own PCB’s is not on my list yet, and to have them manufactured takes a while. So in the mean time I’ll be having fun with THT and perfboards. For me it is a hobby, where I find the part of soldering fun as well. Desoldering not so much, hence the topic.

[james_s]

I've been prototyping lately on blank copperclad, sort of like the old "deadbug" technique. I could never get past the ugly mess it looks like previously but I've managed to develop a fairly tidy technique and it sure performs well for high frequency stuff. Things like SMPS ICs and mosfet drivers that I previously had a lot of trouble getting to work correctly are no problem this way. Big continuous ground plane works even better than a regular PCB in many cases.

[Audioguru]

I mean did you come here to help, or just to show off how smart you are?

My help is for you to read the spec's in the datasheets then calculate what is needed to meet them. Also to buy quality components.
A model was mentioned, for a simulation? Most simulations simply use "typical" active parts, ignoring minimum and maximum spec's so some of the assembled circuits will not work. You can either throw away the ones that don't work or fiddle with them if all the spec's were ignored.

[Siwastaja]

Just curious, but how does one prototype with smd parts without using designed pcb’s?

Easily.

- 0402, 0603 and 0805 passives fit between two pads on standard through-hole breadboards, if you want to use those. SOT-23 and similar also fit just fine,
- For many circuits, use bare copper clad FR4 as a full ground plane. Dead-bug ICs (turn them around), bend the ground pins and solder them down. For power decoupling, you can solder another end of a 0603 cap to the ground copper, another end to the pin directly. For the rest, solder in air wires. Fairly easy to solder a 0603 resistor directly to a pin, leave another end hanging in air, later solder a wire to this pin.

Not much slower than working with through hole parts.

[HendriXML]

Just curious, but how does one prototype with smd parts without using designed pcb’s?

Easily.

- 0402, 0603 and 0805 passives fit between two pads on standard through-hole breadboards, if you want to use those. SOT-23 and similar also fit just fine,
- For many circuits, use bare copper clad FR4 as a full ground plane. Dead-bug ICs (turn them around), bend the ground pins and solder them down. For power decoupling, you can solder another end of a 0603 cap to the ground copper, another end to the pin directly. For the rest, solder in air wires. Fairly easy to solder a 0603 resistor directly to a pin, leave another end hanging in air, later solder a wire to this pin.

Not much slower than working with through hole parts.

With KiCad (which I use) it is possible to flip the board, thus it should stil be possible to have some visual guidance. I’m using that already to create “traces”. Using a perfboard it should also be possible to mix THT and the dead bugs. Dead bugs are then soldered on the bottom side. The “step up” to SMD for me will probably go slowly, so I like this possibility! I know that there’re also adapter boards for SMD, but those aren’t that cheap and you need to have them at stock.

[T3sl4co1l]

I spent a couple years making "useful stuff" like this. I think it's just a phase some of us go through. Prediction. In 2 years, you will be using mostly smd parts and swapping them out with a hot air station.

Just curious, but how does one prototype with smd parts without using designed pcb’s?

With a utility knife:



Note I tend to mix "Manhattan style" construction (PCB chits making elevated tie points) and THT components (which can be wired pretty much anywhere, they're free jumpers).

Tim

[netdudeuk]

You can use the OP's proto board for SMD prototyping

http://elm-chan.org/docs/wire/wiring_e.html

[Buriedcode]

Just wanted to add, SMD parts work nicely with stripboard too.  1206 is usually needed to span tracks broken with a drill bit (broken at a hole) but 0603 or 0805 are fine for connecting adjacent tracks.  Because SMD passives tend to be very cheap (except maybe higher value caps) I use them as often as possible.

[netdudeuk]

The passive components in the photo that I included above are 0805s.  The holes in the board are 0.1" pitch so they fit how the same components would appear on stripboard.

[HendriXML]

Thanks for all the reactions, it really shows there’s not one “right” way to do stuff!