Hi, I hope this is the most fitting category, also it is only loosely a KiCad topic. I spend quite some hours to find a really tiny connector I can use for my project. I only needs to be a 5v dc connector to charge the LiPoly inside.
About right is this one:
sadly that is not produced anymore.
The other approach was to find a micro usb plug that works like this LED:
soldered on the top of the pcb through a cutout so it is reachable from the bottom.
I use the 2-pin JST PH for lots of places where I want to provide dc to a board. Not recessed for a chassis/panel opening like a barrel, but small, polarized, cheap (thru-hole can mount top or bottom):
https://www.digikey.de/en/products/detail/jst-sales-america-inc/B2B-PH-K-S-LF-SN/926611
The de-facto standard is pin-1 positive, as is used for lipos:
https://www.sparkfun.com/products/13853
Iâd just go for the micro USB. De facto standard today, meaning you can find cheap cables everywhere.
Yeah, and usb-c is also getting easier.
This power-only jack is a thru-hole that anyone can solder:
https://www.mouser.com/ProductDetail/CUI-Devices/UJC-HP-G-SMT-TR?qs=zW32dvEIR3vpliH6CJp5Zw%3D%3D
This vertical one is also interesting when you need it to poke out a different direction:
https://www.mouser.com/ProductDetail/640-USB4145-3-0230-C
Well the JST PH are just not made for regular charging (sorry I wasnât very clear about that in my starting post).
The micro USB would be fine if I only could find one that is vertical top mount but plugable from the bottom (like the cut out edge mount types but vertical trough the board).
The other idea was the old, very tiny Nokia power plug (2mm in diameter IIRC).
Or are there power jacks without housingâŚ
EDIT: Ah, I see, it is not possible to explain what I mean without a picture, Iâll try to do a little sketch in CAD to show what I have in mind.
I have used this vertical micro-usb. Easy to solder.
https://www.digikey.com/en/products/detail/w%C3%BCrth-elektronik/614105150721/5047749?s=N4IgTCBcDaIAQDYCMAWJAGArEz6DsYScIAugL5A
If you are looking for something that pokes down through a routed hole in the pcb and solders on top, well I have never seen one like that.
Ah, thanks. Thought so. Iâm now reconsider the general design. Like going for less height rather than less diameter. So Iâll look into those cutout, edge mounted usb (seems more likely to micro-usb than usb-c somehowâŚ)
Yeah, if height is the issue, youâll have to go out sideways, no matter what type of plug.
Connectors can also be placed inside a cutout in the PCB.
A quick search found the example below:
Source:
https://gct.co/usb-connector/usb-orientations-and-mount-types
yup. stupid me. I was searching at mouser and didikey (out of laziness, to have the delivery source and -possibly- the kicad library). But the smallest micro-usb I found is still about 30% smaller than those.
Iâve been using the USB Mini (Not the micro) on a lot of â5V only < 400 mAâ designs. The connector is a lot more rugged than the mini.
Iâve also used the USB A through-hole in both horizontal and vertical. Old, out of date, but still everywhere and will probably go away about the same time serial ports do (i.e. decades).
With the advent of the USB-C âbut just for powerâ parts and the default mode of USB C, on future designs I anticipate going to those parts. The only drawback is an AC (100 to 240V) to USB C âchargerâ is still more expensive than the USB A phone charger in the .5 to 1 amp range. However, the USB C PCB mount is about a dollar cheaper than the USB Mini (from OmRon, and in end of life) so I suspect that USB-C is the correct move in the long run. As for my PCBs with the USB mini, there are USB-C to USB Mini adaptors out there. I donât know if a âpower only, 5V < .5Aâ power source for USB-C will show up in the market place for people who just want a cheap 5V supply or not. The phone market is so huge it seems unlikely, time will tell. Itâs so hard to tell when your âover frugalnessâ will cost more than just doing it right in the first placeâŚ
Note also that most of my applications are for First Responders. They are not known for having a âlight touchâ for anything they do. As such, I really like through hole devices.
Hopefully this explains my thinking, choices, future direction, and biases/constraints.
My first requirement is space. So space wise there seems to be nothing smaller than the micro usb-b type. (especially lentgh). That would be my first choice ion that part. Thinking of what will be most likely will be the âeveryone has already a chargerâ might be usb-c. So maybe it is worth trying to fit the bigger usb-c (with usb 2.0 configuration) into it.
here is the size comparison (green hatch: solder pads, red holes)
All the chargers I have that are spare/left over are USB2.0 Type A out. Some, like the Apple and Android chargers look at the data wires to determine if the device can use more than .5 amps of current. If the data wires are âopenâ, you get .5 amps. USB-C has the same default current of .5 amps for a USB2.0, but can provide .9 amps for the USB3.0. I suspect the âpower onlyâ USB C connectors are good for .5 amps, if you need more than that you should investigate how the USB C decides youâre a USB3.0 and give you more power.
You can get USB-A to Mini, Micro and C everywhere. I have no spare C chargers, and have had to buy some to charge a few devices that can utilized the higher power (drones). I some smaller devices (LEDs for drones) that are USB-C, the USB-A to C cable work for thoseâŚ
Going forward with new designs, I plan to move from Mini USB (which I like for its physical âroughnessâ to USB-C. That CUI âpower only USB Câ part is perfect. I can still use my old USB-A Out chargers with the right cable. Iâve not seen much of anything show up with the USB Mini on it lately. There comes a point where you just need to stop swimming upstreamâŚ
So if itâs just a bit of power for your device (i.e. 5V at < .5 amp) either C or USB Micro works, itâs just what cable you use. If youâre good with the physical integrity of the USB Micro, and space is your primary concern, then use that. If the day comes where there is only USB-C chargers, Iâm sure there will be a USB-C to Micro-USB adaptor out there.
Most of my spare chargers are from old phones, so as phones move to USB-C there will be more of those. But there also seems to be a trend towards wireless charging, giving the phone makers a chance to cut costs by not supplying a charger (so you have to buy the wireless pad on your own).
I respond here because I think your comment on âeveryone has a USB-C chargerâ is a moving target. I think thatâs a bit further down the road, and for now due to both volume and simplicity of circuit, the USAB-A .5 to 2 amp chargers are cheaper than any USB C charger. Again, thatâs a moving target. So if you can fit a USB C, youâre good to go wherever that lands, itâs just the cable from the charger to your board. If this is just a one-up for personal and friend use, and the PCB is done, stay with the USB Micro. Youâll be good for a decade + using the right cable. ML9104 is right on the money with his comment.
Also, Teletypeguy is correct about the JST being common for small LIPOs. Iâd use that vs. solder wires becuase most of the small batteries you can get have that connector on it. (I need to send teletypeguy a pix of my PDP-8 with a KSR-35 from the '70s that I had/haveâŚ)
Iâm still looking at the USB power chips out there for whenever the time comes I need more that 2.5 W of power for something (or a hight voltage). Right now, every project using small uPs and itâs hard to get anything to draw more that 50 to 100 mA.
Good luck and happy debugging on your project !!!
Hah! Iâd love to see your pdp with the 35. I have a 35-RO you can for parts or refurb if you want (ro=read-only which is in a ksr case but blank plate instead of keyboard).
I had the 35 stored, and it got thrown out. But I got an ASR-33 which I still have. I also still have the PDP-8. It does not work, a bit in the core memory blew out around 1980 or so.
I got the machine from DEC in Maynard Ma. in 1972 when I was still in high school. They were taking it off the assembly line. Serial # 818. I bought the processor and the high speed paper take reader and punch. Got the 35 from a place that was getting rid of them. What a great machine to learn âsmall systemsâ programming, set me up big time for when the Motorola MC6800 came out.
In the pix, you see a small wire wrap board (red blob) hanging down. That was a special DTMF generator I made for it. The summer of '72 I made some of my 1st PCBs and converted the DEC buss into TTL so I could add peripherals. Later, in 1975 I wire wrapped up a NTSC display, patched FOCAL, and went from 110 baud to around 30K baud. 16 lines of 64 characters each using the ânew fangledâ 1K bit static rams and the Signetics 2513 character generator ROM. Living large.
Also a CarterPhone acoustic couple modem above the cinder blocks. I pretty much spent every penny I earned either buying HeathKits or chips to build stuff from.
Made my PCBs with a positive resist system, used the sun for UV exposure clamping the positive art (Bishop Graphics) on overhead projector sheets from High School and then developing, etched scrap copper from a Honeywell plant, and drilled with a dremel. Good times.
It is wonderful to see how much easier it is today. Test equipment is cheap, PCB layout using KiCad rocks, and OSHpark for fab is fabulous. And oh yeah, computers are a bit cheaper and a lot faster.
Ok, the is wildly off topic, hope no one is too offended. To the OP: Keep making boards, keep developing your skills.
Perhaps you only noticed they were no longer being manufactured and didnât see there are over 1000 units currently in stock and can ship Immediately⌠But, perhaps you need more than thatâŚ
Ahh, thatâs really cool Pete. The old DEC gear was just iconic. Looks like your 35 had a twx dialer. The 35 was a great 24/7 machine, an ascii version of the baudot model 28, but the 33 is more collectible, even though it was a cheaper and less-rugged design. I did my share of etching boards back then, and using the 4x bishop graphics pads and tape on a light table. Simpler times, and seems like it was more gratifying to design stuff back then.
@BlackCoffee I did noticed, but I was actually surprised how big those are still compared to USB connectors. So I did a bit of rethinking my design and instead of go for some standard power only plug plus some strange internal usb connection for programming, I now have an idea to do it with an usb connector only, on a small daughter board.
Iâve made small products where I use small 1/8" Earphone connectors (sometimes called âJacksâ and âPlugsâ (I have two patents on Medical related connectors and take Connectors seriouslyâŚ)
I thought about those, too. But since I have in mind to have some universal board, that can be used in the arduino âuniverseâ, I do aim not to stray to far from the âusualâ.
