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Marcus Müller
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Now, digital lab might or might not mean you're doing high-speed stuff – and breadboards are, due to the shape of all the conducting parts, especially prone to produce interesting cross-talk or attenuation.


as a personal remark:

I did and still do some prototyping, even on breadboards. However, I've been frustrated a lot in the past, so now I have basically one breadboard (not model, a single specimen) that I trust, and I basically only use it to plug in PCBs that I ordered or made myself with 2.54mm pitch pin headers, and a few jumper cables to power the boards, and maybe decoupling caps for the power supply. I can rely on the contact of these few select components, from experience.

I've been bitten by unreliable contacting, especially of wired resistors, so often, that I at one point realized that I can either debug a prototype that might or might not be failing either due to a problem with my design or a problem with the contacts in my breadboard, to simply not do anything even remotely complex on breadboard. If something is done on PCB, you can, as long as you know how to solder, rule out bad contacts as a source of error. And that's pretty relieving.

Designing my own PCB actually is faster than figuring out how to build a complex e.g. four-transistor device with a couple of biasing diodes and resistors as a rectangular breadboard design. And, if I have enough work left in queue to do while I wait for PCBs, I can order things for cheap somewhere in China. For private stuff, and small PCBs, a triplet of PCBs is definitely cheaper than the cost of a high-quality breadboard divided by the generations of students that will use it.

Of course, it's absolutely true that teaching students how to design a schematic and layout a board might be out of scope for the lab you're heading – it might be an interesting thing to learn, nevertheless.

As said, I don't know what kind of components you use. But assuming those are more things like discrete transistors, and DIP logic gates (7400 family kind of things you're building – but aft), and maybe one DSP/FPGA/microcontroller/PC interface board to connect to those, maybe a middle ground would be interesting:

Soldering a TO-92 transistor or a DIP14 IC and pin headers onto stripboard or perfboard isn't actually very hard to do. Students might still be able to interactively experiment with circuitry if they have soldered down their elementary circuits themselves and use external, good quality jumper wires (don't get me started on the quality of jumper wires) to connect those, if signal frequency permits.

Now, digital lab might or might not mean you're doing high-speed stuff – and breadboards are, due to the shape of all the conducting parts, especially prone to produce interesting cross-talk or attenuation. I don't know what kind of things you're building – but aft

Now, digital lab might or might not mean you're doing high-speed stuff – and breadboards are, due to the shape of all the conducting parts, especially prone to produce interesting cross-talk or attenuation.


as a personal remark:

I did and still do some prototyping, even on breadboards. However, I've been frustrated a lot in the past, so now I have basically one breadboard (not model, a single specimen) that I trust, and I basically only use it to plug in PCBs that I ordered or made myself with 2.54mm pitch pin headers, and a few jumper cables to power the boards, and maybe decoupling caps for the power supply. I can rely on the contact of these few select components, from experience.

I've been bitten by unreliable contacting, especially of wired resistors, so often, that I at one point realized that I can either debug a prototype that might or might not be failing either due to a problem with my design or a problem with the contacts in my breadboard, to simply not do anything even remotely complex on breadboard. If something is done on PCB, you can, as long as you know how to solder, rule out bad contacts as a source of error. And that's pretty relieving.

Designing my own PCB actually is faster than figuring out how to build a complex e.g. four-transistor device with a couple of biasing diodes and resistors as a rectangular breadboard design. And, if I have enough work left in queue to do while I wait for PCBs, I can order things for cheap somewhere in China. For private stuff, and small PCBs, a triplet of PCBs is definitely cheaper than the cost of a high-quality breadboard divided by the generations of students that will use it.

Of course, it's absolutely true that teaching students how to design a schematic and layout a board might be out of scope for the lab you're heading – it might be an interesting thing to learn, nevertheless.

As said, I don't know what kind of components you use. But assuming those are more things like discrete transistors, and DIP logic gates (7400 family kind of things), and maybe one DSP/FPGA/microcontroller/PC interface board to connect to those, maybe a middle ground would be interesting:

Soldering a TO-92 transistor or a DIP14 IC and pin headers onto stripboard or perfboard isn't actually very hard to do. Students might still be able to interactively experiment with circuitry if they have soldered down their elementary circuits themselves and use external, good quality jumper wires (don't get me started on the quality of jumper wires) to connect those, if signal frequency permits.

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Marcus Müller
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Is there a tool I can use to check pin-by-pin?

I know research assistants can be cheap labor, but considering the price of breadboards: If this is necessary, you might simply want to invest into higher-quality or simply new breadboards.

Even as a 13 year old pupil, I simply threw away a couple of breadboards that I bought from my small earnings after figuring out they were simply not manufactured accurately enough to ensure reliable contact with DIP components. Your boards are probably a lot better than mine were, back in the day – it seems they at least have a base – but they might have seen a couple occasions of rough usage due to being used in an educational facility.

What are the problems that can plague a breadboard, and how can I diagnose them?

Use your imagination!

  • weak contact due to mechanical fatigue
  • dirt
  • effects like stray capacitance, inductance, resistance
  • unsecure connections due to poor mechanical contacting, as components aren't made for breadboards, but PCB manufacturing
  • lots and lots of other things that might go wrong

It's impossible to tell what's wrong in your particular case – use your EE experience to rule out things, if that's the route you want to be taking.

Now, digital lab might or might not mean you're doing high-speed stuff – and breadboards are, due to the shape of all the conducting parts, especially prone to produce interesting cross-talk or attenuation. I don't know what kind of things you're building – but aft