I’m making a simple power supply. 12v in : 5v or 3v3 out.
It’s all going in a 3d printed case I’m hacking up.
Here is the 3v3 regulator as example. I’ve the 5v and 9v as well when I’m ready.
The power supply is 12v 5a, so each of the regulators gets a 2a fuse plus an additional 5a fuse for the entire supply just in case.
My plan was to chuck the regulators and there fuses onto a solder-able bread board. Might have 2 regulators running in parallel in some applications (and a common gnd). Exact requirements are all a little fuzzy, so to be safe I’m factoring in 5amps of to future proof.
However, I recently learned a valuable lesson about having nice thick gauge connections for power. I’m now concerned that the bus on the breadboard might not be sufficient to carry 4 or 5 amps.
Instead of soldering cable to the regulators directly, It would be nice to use the header pins so that I can hot swap out the regulators for other voltages in future if I reuse this idea.
I’m looking for some kind of female header connection that can handle min 60w.
Something I could then connect 22awg stranded cables to. Bonus points if I can easily incorporate it into the 3d print with some screws.
The technique I have used in the past is to use solid copper wire. Find a size that fits neatly in the thruholes of the regulator and solder both sides. Then use a suitable sized screw terminal or spring clamp connector mounted on the breadboard. Bend the copper wires to fit and so that the regulator is held off the surface of the breadboard. Then run the 22AWG wire direct from the connectors to the fuses. The breadboard is there to provide a mounting surface for the connectors and fuses, and the 3D print can be configured with either slides or screw mountings for the breadboard.
Any connection that uses breadboard traces can be replaced with the heavy gauge wire, provided the devices (like fuses and connectors) have sufficiently beefy pins. Note that, for instance, the spring connector I linked has two pins per connector. My understanding was that you needed to have the regulator wired with cable of similar current capacity, but removable. That’s what the copper wire and terminals does for you.
Ok I can see all the steps I could take to make that work.
I might have to use enameled copper wire which is not my favorite to work with.
I think I was secretly hopeing for an off the shelf solution.
This is a great fallback though. (might be the only/best solution).
On a side note, as per the heading “… to a 3d print”.
Keep in mind the material of the 3D print (e.g. PLA) and the heat if any that needs to go somewhere.
e.g. I had a 3mm thick PLA plate, taped some WS2812B leds to it and the heat from those allowed the plate to warp. So if your regulator needs to dissipate a fair amount of heat (I would say starting from about 40-50Deg C), you will need to keep that away from the plastic and vent the heat.
of course different plastics will have different “safe” temperatures, so adjust the numbers to suit what you are using.
What is wrong with tinned copper wire. Enamel can be risky if not cleaned properly but I think these days most of it is “solderable” enamel which has been around for quite a few years now.
Hot swappable??? Be a bit careful, some of these DC to DC converters have a fairly high inrush current, depends on the size of the input caps. I have not seen any inrush figure published for most of these devices. Better quality brands like MeanWell etc do so. As an example I have a Meanwell 5V 14A power supply with an inrush current Quoted as 40A (I think from memory) and that would be at 240V.
Hot swappable devices and PC boards I have had experience with have been especially designed for the job. Even with special connectors with different length pins so you have some control over just what part of the circuit gets connected first.
Hi Jeff and All
Be a bit careful with these linked connectors
If they are in fact 5mm pitch as drawn you will not be able to link too many together before they will no longer marry up to the standard 2.54mm or 0.1" board pitch.
Could be a drawing error as I note they are marketed through a 3rd party brand and might be in fact 5.08mm pitch as is the norm with this style of terminal.
I do note that the supplied pic shows the presence of a wire protector which is a good thing.
Cheers Bob
I guess the holes are so close together that I don’t trust the wire not to one-day cross and short.
Doing this hole hot-swappable thing has so many steps it might be faster just to wire it and do some fancy de-soldering in the unlikely event that it breaks one day.
The copper wire can be bent to accommodate the physical layout that best suits the components. For instance, you might like to use extra spacing between the connectors to minimize any risk of contact and to simplify the soldering. If they are longer than a few CM use sleeving.
If you use enameled wire you can twist it back and forth a few times while gripped with pliers to remove the enamel for a short distance at each end. But do not rely on enamel alone to insulate them if there is any risk of contact. It can be used in transformers because the potential between adjacent turns is relatively low - that won’t be the case for your PS.
Whether or not long rows can be used depends on the molding size, not the pin spacing, and both 5.0mm and 5.08mm components have been designed with that consideration.
Hi Jeff
Yes, those do align OK.
They also look like genuine Phoenix Contact terminals in which case there is every likelyhood they could be 5.08mm pitch.
Cheers Bob
I’ve done some soul searching about what I value and decided that I’m just going to use male to male jumper wires and accept that any mods will require de-soldering. Hotswaps aren’t worth it for me although @Jeff105671 that was a great solution thanks
