Prototyping with Power Elctronics

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I am starting a new project, and I will be working designing specialty electric
motors. I am anticipating a problem prototyping the electronics.
I will be using electrical components capable of relatively high voltage and current.
The problem is that they are physically large. I cannot plug them into a standard
breadboard, and if I could with the amount of power being used would fry the Breadboard.
Also the wires used prototyping with a standard breadboard could not carry the current
I will be using. This is my problem and I have looked on the internet and I cannot
find a solution, can you help ?

Thanks
V. Evans

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Hi Vaughan
I think your only solution is go back to pre breadboard days. Out with the soldering iron and carefully “rats nest” everything.
You will probably have to mount the motors somehow anyway. You could not have motors of any size (for that matter small ones too) gyrating around the bench semi out of control wrecking everything in its path.
Fun days.
Cheers Bob

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Would test leads with alligator clips be adequate? There are leads with alligator clips at either end, others with a breadboard pin at one end and a clip at the other end. There are clips to handle currents over 100A (like jumper leads). I have prototyped with galvanised nails hammered into board and soldered components between nails. Not so easy to change components as with the alligator leads, but more robust.

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Hi All
I think Alan’s word “robust” says it all. With Higher voltages and current this sort of thing is a must. You just cannot have stray bits of wire hanging about without having some sort of disaster.
Cheers Bob

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You should fabricate your own design of ‘breadboard’ using terminals that can be screwed onto a base and are appropriate for the current and voltage that you will be using. For instance:

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I have 20 “Terminal block, pluggable 3 pos 10AWG”
and will soon have 25 “Terminal block pluggable 2 pos 12AWG”

Basically little 2&3 wire terminals with large wire sizes.
I assume they can take large current
My plan is to build a simulated Breadboard with the terminals
a 3D Printer and some super Glue.
The problem is I do not have a working 3D Printer,
I would prefer a Power Breadboard but this is my fall back plan!
Thanks
Vaughan

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Hi Vaughan
Yes, terminal blocks that will accept that size wire would be expected to carry the same current as the wire. If you can find any data sheet on the blocks that should give you some idea.

The idea to assemble this into a breadboard style unit has merit but don’t forget to use large enough wire to connect them or you may end up with lots of little fuses.

A little tip. If you are going to make up links of wire to interconnect all this and you will be putting wires under screw terminals get yourself some “bootlace ferrules” of the correct sizes for the wire and a ferrule crimping tool to fit them. If any wires are to go into screw terminals they should be fitted with ferrules anyway. This will avoid damage to the wire strands and you will be able to swap and change many times without trouble and they will essentially stay in good condition.

DO NOT tin wires with solder that are going into screw terminals. They will NOT stay tight and will be unsafe for your application.

The “bootlace ferrule” crimping tool IS NOT the same as the tool used to crimp connector pins or connectors and such a crimper will not do the job properly. If you intend playing with this sort of thing you will find the proper tooling a worthwhile investment.
Cheers Bob

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I checked the max current 24A, I will not need any where that amount
the Terminals are pluggable. I do not know what “bootlace ferrules” are, so I googled them
I had not seen therm before … thanks for the tip
Vaughan

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That doesn’t really address the problem. Those terminals need to be connected together somehow to create a bus. The only way they could be used for breadboarding is if you connect multiple wires to each socket. They aren’t designed to work like this, and you woiuln’t be able to use ferrules. Twisting wires to together to insert into a single connector is not good prototyping practice. Also, mounting them will be difficult, as you indicate.

The suggestion I made was for small bus bars - strips of connected terminals… The ones that Core stocks might be overkill in terms of current capability, but other similar products are probably available elsewhere. The advantage is that they can be easily secured to a simple wooden base (a breadboard would work very well) and each wire has its own secure connection, so there is no need to double up the wiring, and you can use pre-made lengths of wire with ferrules.

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Hi Vaughan
I think Jeff’s idea of using bus bars is the better one although it requires screwing instead of plugging. The advantages are ease of mounting to a base as Jeff notes and the fact that the connections are already connected together as in the little sockets on a breadboard. As Jeff said they are available in different sizes and if Core don’t have suitable ones they are readily available at most electrical wholesalers.

Not good practise anywhere. Especially in terminal blocks where some cheaper types don’t have any wire protectors fitted. If under a bare screw there is a good chance the screw will cut some of the wire strands. Hence the recommended use of ferrules.
Twisting wires under any clamp type of terminal is not good as the wire strands can cut or come loose. The strands should be straight or at worst be in their original lay in the cable. In no circumstance should different size wires or stranded and solid core wires be under the same screw clamp. The different sizes or the stranded and solid must be put into the same ferrule and crimped before terminating.
Vaughan I think in your case where the possibility of several changes to be made bus bars and ferrules on the wires would be the way to go and you should minimise problems.
Cheers Bob

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