Project scope: solderless prototyping work

[Pahriuon]

Hello guys,

I'm an aspiring entrepreneur, I would like to develop a new solderless prototyping tool. This prototyping tool should be better than breadboards in three aspects:
1) more convenient construction, hopefully more ordererly construction and less ratnests.
2) suitable for high frequency circuits.
3) has a higher power rating than breadboards, suitable for power electronics.

I'm working with lancers on the project, engineers, but I'd like to know your opinions on #3 obviously.

So, I don't have much experience in electronics I'm your average beginner but I especially don't know much about power electronics, what I read so far discusses it as a branch of electrical engineering, on the professional side, so I don't know the range of projects for the amateur side. The presumption I have of it is bulky components that run many many ampares, but what size what current? I have no idea.

The information I need for my project is:
1_ is there a de facto component size for power electronics? as I need to know wire sizes?
2_ how many ampares do you want to take this prototyping tool up to? 1 A? 5 A?

Think of me as a designer: I know you like breadboards and you wish you could use them for your power electronics projects, tell me all that you want.

"To reach where you want, you must first know your destination".

 

[KlausST]

Hi,

A diificult challenge.

I often see users trying to test a switch mode power supply on a breadborad.
(I call this useless)
Maybe with continous currents if less than one Ampere you get switching currents of many 10s of Amperes.
Switching frequency of 1MHz or above. Shunt resistors of only a few milliohms.
I can't see how this can reliably tested on a breadboard.
The design notes tell to use short and wide traces, which often means less than 5mm in length.
A non SMD device with it's wires may be unsuitable.

And this is not by the ohmic resistance if a wire, it is because of the impedance of the wire. For low impedance you don't need only short traces, but you have to consider the current return path...and the area enclosed in both paths.

In my lab I currently work on a 10kHz (not 10MHz!) switching application. I could show you how huge the difference is if two wires (very low impedance power path and it's return path) are in 3mm distance or 10mm distance.

The difficulty really is how you manage to route high frequency paths short, with low cross coupling, low inductivity and low capacity.
..and high current (switching) paths. I have no solution...

Klaus

 

[Pahriuon]

Hi,

A diificult challenge.

I often see users trying to test a switch mode power supply on a breadborad.
(I call this useless)
Maybe with continous currents if less than one Ampere you get switching currents of many 10s of Amperes.
Switching frequency of 1MHz or above. Shunt resistors of only a few milliohms.
I can't see how this can reliably tested on a breadboard.
The design notes tell to use short and wide traces, which often means less than 5mm in length.
A non SMD device with it's wires may be unsuitable.

And this is not by the ohmic resistance if a wire, it is because of the impedance of the wire. For low impedance you don't need only short traces, but you have to consider the current return path...and the area enclosed in both paths.

In my lab I currently work on a 10kHz (not 10MHz!) switching application. I could show you how huge the difference is if two wires (very low impedance power path and it's return path) are in 3mm distance or 10mm distance.

The difficulty really is how you manage to route high frequency paths short, with low cross coupling, low inductivity and low capacity.
..and high current (switching) paths. I have no solution...

Klaus

Okay, excuse my ignorance but if we divide circuits according to frequency and power, won't we have this result?

1) low power, low frequency (typical beginner circuits)
2) high power, low frequency circuits
3) low power, high frequency circuits
4) high power, high frequency circuits

Now why don't we discuss all of them:
1) Since the tool is supposed to be superior to breadboards, reliable #1 circuits should be made with ease
3) #3 circuits like these include radio frequency circuits, my tool allows the insertion and removal of component leads and wires (hence circuits are constructed, non-SMD circuits, SMD components are not in my scope).

Component leads and wires would "hover over" a metal plane, they would be close but not touch the metal plane. This metal plane is also connected to the circuit as it acts as 0 V (GND), which allows coupling between each wire and this ground plane.

The setup would allow for free-form design, so wires and components can be laid out according to RF circuit construction concerns. The product brochure (or manual) would also give instructions relating to these concerns; wire lengths, distance between wires, orientation, etc, well hopefully that is what I aim to do.
Do you think this setup would help in the prototyping of RF circuits?

I realise the task of setting up a RF circuit to act desirably is a case by case job, but my goal now is to make that as easy possible for product users.


2) Back to our topic of discussion, are there high power low frequency circuits out there? That 10 KHz circuit you mentioned, under which category would it fall into?


4) I've determined that these circuits are out of the scope of my project

 

[KlausST]

Hi,

First: Please don´t think I want to stop you from developing a new breadboard system. I don´t want to discourage you. I just want to give my personal opinion.
***

Even if you divide the applications in your given categories...

It will be difficult.
* even relaitvely low power (<5W) high frequency SMPS are difficult to route on a PCB. And wiring on a breadboard is even more critical.
--> It´s not a problem of the breadboard itself. In many cases the users of the breadboard just don´t see where the difficulty lies. But without this knowledge ... even the best breadboard system is useless.

An example:
If you give a high tech welding machine to somebody... this doesn´t mean that the person can handle it. The person needs to know the theory behind welding: Choosing materials, choosing correct welding current, using the correct technique and so on.

***
1) those breadboards already exist
2) This sounds useful to me. Afaik existing bread board systems don´t provide high current paths. But how to set the limits? 10A, 30A, 100A? What voltage rating? 230V AC (for beginners)?
3) This sounds useful tom, too. But I have no idea how to achieve this. Even the wires of THM devices may be too long, and now the breadboard-matrix...?
4) I´d say this makes no sense. One needs a lot of experience to build those systems. In the very most cases one need a special PCB layout to achieve good results.

Klaus

 

[Pahriuon]

Hi Klaus,

Thanks for the reply man. I wasn't trying to be defensive earlier I just wanted to separate topics so we could have a useful and orderly discussion, I do value and want your personal opinion.

What I'm striving for is something more versatile than breadboards, at least as versatile as I can reasonably make it, so I don't want to think of it nor call it a breadboard, it's a new solderless prototyping tool for through-hole components, it's not a breadboard. By using different parts of the tool system, one can construct different types of circuits, and I've got some initial design ideas, quite simple really no fancy engineering. But anyway that's not what I'd like your help with.

What I'd like your help with is my work scope: these high power low frequency circuits (maybe DC circuits) have you ever used such circuits? I'd say my current limit is the limit that end users want, so if you've used such circuits, how many Amperes have you gone up to?


"For one to reach where he wants, one must first know his destination"

Thanks bro,
Hamoud

 

[KlausST]

Hi,

Lucky me, I had the chance to designs, very low measurement current in the picoamperes range (not suitable for a prototype board)
up to 6000A current control loop (not suitable, too). And a lot inbetween.

I never used a breadboard. I very rarely use simulation tools. I'm a friend of reading datasheets and application notes.
Usually they tell you all you need to do a design. Some experience helps to recognize where the critical detail in a circuit is.
I like to design critical circuits, I like the challenge.

In the forum I see a lot users building SMPS and UPS. DC, AC, switching, I'd say 1A maybe up to 50A.
Audio amplifiers from 1W to hundreds of watts, linear and switching.
And many microcontroller systems with periferals, in the milliamperes range.
And I see a lot of analog sensor signal conditioning circuits. Often problematic.

So where is your focus?

Klaus

 

[Warpspeed]

I think the reality here is that practical prototype circuits can be separated into functional parts, all of which need not be built in the same way.

Take for example a ten amp linear voltage regulator.
It might have a large transformer, a large electrolytic, and a power transistor fitted to a heatsink. All those parts would need to be connected together, and soldering is the obvious way to do that. Its quick, easy, practical, and we all own a soldering iron.

Now where some kind of special prototyping gizmo might come in useful is in hooking up the feedback and analog control system. The ubiquitous breadboard is pretty ideal for that. But if you have a better idea, go for it.

There are other applications such as very high voltages and very high frequencies which often use highly specialised parts that need individual consideration.

If its a 2Ghz counter, some critical low noise video system, or runs at 25 Kv its difficult to imagine some universal type of prototyping tool that could deal with those extremes.

But for the more common type of op amp or microccontroller prototyping which we all do, a superior type of breadboard would certainly be most welcome.

But it does not need to have high power or high voltage capability or anything special. Just be very robust simple and reliable, which breadboards are not after some limited period of use.

 

[Pahriuon]

Hi guys,

Hi,

Lucky me, I had the chance to designs, very low measurement current in the picoamperes range (not suitable for a prototype board)
up to 6000A current control loop (not suitable, too). And a lot inbetween.

Hehehe well I suppose your not my average end user then, kudos to you Klaus.

In the forum I see a lot users building SMPS and UPS. DC, AC, switching, I'd say 1A maybe up to 50A.
Audio amplifiers from 1W to hundreds of watts, linear and switching.
And many microcontroller systems with periferals, in the milliamperes range.
And I see a lot of analog sensor signal conditioning circuits. Often problematic.

So where is your focus?

Klaus

I think the reality here is that practical prototype circuits can be separated into functional parts, all of which need not be built in the same way.

Take for example a ten amp linear voltage regulator.
It might have a large transformer, a large electrolytic, and a power transistor fitted to a heatsink. All those parts would need to be connected together, and soldering is the obvious way to do that. Its quick, easy, practical, and we all own a soldering iron.

Now where some kind of special prototyping gizmo might come in useful is in hooking up the feedback and analog control system. The ubiquitous breadboard is pretty ideal for that. But if you have a better idea, go for it.

Microcontroller systems with periferals, in the milliamperes range is an absolute must. As for maximum current: 5A seem to come up frequently, I think I'll settle on that.
As for other circuits I suppose the best way to determine whether my tool is suitable for what circuit is to prototype it, test those various circuits with it and optimise it to see how far it can be taken. I'll be able to figure out the details then.

But for the more common type of op amp or microccontroller prototyping which we all do, a superior type of breadboard would certainly be most welcome.

But it does not need to have high power or high voltage capability or anything special. Just be very robust simple and reliable, which breadboards are not after some limited period of use.

I think I've got robustness and simplicity down, long-term reliability on the other hand might be an issue. My project utilises pins which obviously cannot endure repeated wire insertion/removal forever. Perhaps I should make those pieces as cheap as possible so replacement wouldn't be an issue.


One last questionower electronics' components' lead sizes, is there a de facto size? or are there variations in the components as the power range goes up? enlighten me please.



Thanks,
Hamoud

 

[Warpspeed]

Huge variation in lead diameters.
Some capacitors have unusually fine wires.
Some power diodes have unusually thick leads to conduct heat out of the device.

This is the great failing point of breadboards. Once you have forced the fat legs of a large electrolytic into a hole, it will then never again grip a really fine wire leg of something much slimmer.

I just grabbed a 1N5408 diode, 1.00 mm diameter leads
A 1nF polystyrene capacitor 0.47mm diameter leads.

 

[Pahriuon]

This indeed looks like a challenge, perhaps I should make a thread just for it.

Thanks Tony

 

[Aussie Susan]

In addition to the above, also think about the impact of the breadboard itself on the circuit.

For any type of circuit, you must ensure the wires do not touch under the board. If you have a metal backplane (I think you mentioned that at some stage) then they must never actually touch that.

For high power (which typically involves high voltages, high currents or both) you need to be sure that the connectors are far enough apart to allow an arc between them. Also that the conductors are sufficiently sized to carry the current - you mention 5A; have a look at typical house power plug wiring which (at least where I live) is rated at 10A and is quite thick for safety reasons. You will need to ensure the conductors are over-spec'd so they never cause problems when circuits malfunction due to poor (partial) design.

For high frequency circuits, you need to account for the capacitance between the breadboard connectors which is a common problem for people using frequencies above about 1MHz. High frequencies can also cause induced currents in nearby conductors so good isolation is required.

Susan