Banana plugs - enlighten me. Also running Rigol DP832 is parallel - Page 1
Forum section: electronics / general

author: confusion
author_rank: Contributor
timestamp: June 04, 2024, 11:03:55 am
content: So, I'm looking at making some of my own banana plugs to a run a Rigol DP832 benchtop power supply in parallel to make it 30V/6A instead of 30V/3A.Which made me wonder if there is any difference between typical 'audio' banana plugs and 'power supply' banana plugs.I was just looking at some audio plugs that I have and it seemed like if I ran power through them, the whole metal casing wouldn't be insulated? Just wondering if that's the case and why it isn't a problem for terminating speaker cable with them? or am I an idiot and they are actually isolated?https://imgchest.com/p/ne7bxwmkvy5Second question:What's the least janky way to run the DP832 in parallel. Are there some considerations/gotchyas I haven't thought of?I've done a tiny bit of research and the term 'voltage tracking' or something has come upI wanted to combine CH1 and CH2.How would this work setting voltage and current? Would I have to set both channels to the exact same every time?Thanks a bunch

author: eutectique
author_rank: Frequent Contributor
timestamp: June 04, 2024, 11:12:37 am
content: DP832 manual, page 2-8 onwards, section "Power Supply Series and Parallel Connections".

author: confusion
author_rank: Contributor
timestamp: June 04, 2024, 11:41:34 am
content: Quote from: eutectique on June 04, 2024, 11:12:37 amSo for the wiring I'll get a cable with a banana plug at each end. Cut it in the middle, and terminate the now bare wires into a third banana plug (this 3rd plug sitting in the middle will go to the load and I'll probably attach a crocodile clip to it)Obviously do this once more for the negative.As for the 'track' function. I'll be setting this to synchronous? Will it persist through shutdowns?Am I right in thinking the only difference between setting track to CH1 vs setting it to BOTH CH1 and CH2 is: When I want to change voltage/current I have to always use CH1 in the menu. But if I set track on both channels, I can change the voltage/current from both?Sorry if I haven't worded that very well. But it doesn't seem like much of a difference? just the accessibility of changing the voltage/current being either relegated to one channel or both...Thanks for the help, much appreciatededit: How anal do I have to be about making the wires the exact same length?

author: Ian.M
author_rank: Super Contributor
timestamp: June 04, 2024, 01:11:10 pm
content: I wouldn't do that. The binding posts are also screw-down, so simply get some fork crimp terminals to fit, and make up two short jumpers just long enough to reach the end binding posts comfortably, which will cover any supported combo of series or parallel you may need.Simply fit the jumpers and screw down the posts securely, then plug in ordinary banana leads to connect to your load.OTOH a few leads with stacking banana plugs can be very useful, e.g. if you need to hook up more than one load to the same supply, or set up a meter to measure volatage at the load.

author: confusion
author_rank: Contributor
timestamp: June 04, 2024, 03:07:36 pm
content: Quote from: Ian.M on June 04, 2024, 01:11:10 pmThat does make a lot more sense and gives me more versatility if I want to do some 48v work which I occasionally do. Effectively bus barring CH1+ to CH2+ by unscrewing the terminals just enough to get the forks over the back of the terminal, then using the regular front access banana holes (lol) and obviously doing the same with the negative.My only concern would be once I've unscrewed them enough to get the forks on, the front banana holes mightn't give enough depth/penetration? Probably not an issue TBH.While you're here, I found a weird and wonderful world of banana plug designs on Alibaba. They have like 5+ different designs mainly in how it flares out. I can't imagine there's a crazy amount of difference but I guess some would be better for certain applications? I think the most popular is called a lantern style, but they had a bunch of them. Here's a set I ordered because they looked cool and one of the Ali commenters swore by them. I hope they have a good contact area.What are your thoughts on the original banana plugs I mentioned, and not feeling comfortable doing PSU work with them?Thanks for your help

author: AVGresponding
author_rank: Super Contributor
timestamp: June 04, 2024, 04:04:52 pm
content: You might be better off getting banana plugs from somewhere like Element 14 or whoever your preferred trade supplier is locally, the ones you get from places like ebay/Amazon/AliX etc are very risky in terms of quality and dimensions.

author: confusion
author_rank: Contributor
timestamp: June 04, 2024, 04:13:56 pm
content: Quote from: AVGresponding on June 04, 2024, 04:04:52 pmYeah that's fair.Probably a bit harder to test what's good or not too as I assume it comes more down the the contact area and spring tension right? Not something as easily measured as something like resistance.Let me know if I'm talking nonsense, it's the only way to learn.Thanks for your time

author: AVGresponding
author_rank: Super Contributor
timestamp: June 04, 2024, 04:24:31 pm
content: Contact resistance is one factor, but also some don't makeconsistentcontact; the resistance changes when you move/wobble/touch them. Some are oversized, and can damage the sockets they are inserted into. Some areundersized, and just fall out of sockets when you try to use them...

author: confusion
author_rank: Contributor
timestamp: June 04, 2024, 07:18:59 pm
content: Quote from: AVGresponding on June 04, 2024, 04:24:31 pmWhile you're here...I've been on an eternal quest to find a DC connector that's good for something like 5 to 20 amps, waterproof and not ridiculously overpriced. I'd love to use them on an off grid property I often work on. Closest thing I've found is an MC4 solar connector.Are there any really awesome connectors out there that I should look in to?Thanks a bunch

author: AVGresponding
author_rank: Super Contributor
timestamp: June 05, 2024, 04:20:13 pm
content: I would guess you've found the best option there; high current DC connectors are common for RC models and drones, but I'm not aware of any specifically waterproof ones (not into model boats, maybe they have them). Even boats (full size ones) don't generally use waterproof connectors, just things like Anderson connectors (that I've seen, at least).

author: IanB
author_rank: Super Contributor
timestamp: June 05, 2024, 04:31:20 pm
content: Quote from: confusion on June 04, 2024, 07:18:59 pmHave you looked into IEC 60309?https://en.wikipedia.org/wiki/IEC_60309#Extra-low_voltage_variant

author: reboots
author_rank: Regular Contributor
timestamp: June 05, 2024, 07:06:36 pm
content: Quote from: AVGresponding on June 04, 2024, 04:24:31 pmThe contact material may also be steel, or some unknown diecast metal, with an equally mysterious plating which might flake or tarnish. The plastic might be ABS or some other cheap thermoplastic. This is a safety issue: high resistance and/or a poor connection can cause the contacts to heat and degrade, melting the plastic and shorting the jack to the chassis.I bought a set of no-name Chinese banana jacks not long ago. The threaded metal body was apparently die-cast, and the barrel ID had significant burrs and other blemishes. These jacks would have scraped and damaged the plug on first insertion. Any premium to avoid this type of part is money well spent.

author: tooki
author_rank: Super Contributor
timestamp: June 05, 2024, 07:09:09 pm
content: Quote from: confusion on June 04, 2024, 03:07:36 pmShould not be any problem whatsoever.Quote from: confusion on June 04, 2024, 03:07:36 pmI concur with avoiding no-name banana plugs. Some are fine, some are useless from the start, some appear fine at first but wear out super quickly. It’s not worth it, given that even top-quality banana plugs only cost a few $ each — and those will last for decades.I highly recommend Stäubli and Hirschmann. They both make, among other styles, the best lantern-style banana plugs out there. (That technology is kinda Stäubli’s specialty.) The ones you bought are clones of the Hirschmann “Büschelstecker” style.The other brand I like a lot is Pomona. But most of theirs are American-style banana plugs, which are shorter and aren’tquiteas universally compatible as the slightly longer European-style ones.The budget ones I’ve had good luck with is the Deltron 553 series. I’ve been using them a lot at work, and the users haven’t reported any trouble with them.Finally, another favorite of mine are the WAGO 215 series, which are fabulous for temporary connections. I use these all the time at work.

author: MarkF
author_rank: Super Contributor
timestamp: June 05, 2024, 07:30:48 pm
content: Just get some stackable banana leads. They're good for making other connections too.I bought a couple sets of the Elenco Banana Test Leads - TL-18.

author: confusion
author_rank: Contributor
timestamp: June 06, 2024, 04:53:18 am
content: Quote from: IanB on June 05, 2024, 04:31:20 pmAt first glance those look bulky, filthy expensive and more suited to AC loads that'll get plugged and unplugged a lot.MC4 are really cheap, waterproof, and not at all bulky. But they are a shit to open up even with the special tool sometimes, and I have my doubts about how many times you can open and close them without doing damage.1000V / 30A gets a lot of jobs done.

author: confusion
author_rank: Contributor
timestamp: June 06, 2024, 05:17:23 am
content: Quote from: tooki on June 05, 2024, 07:09:09 pmThanks for the recommendations. I'll jump on element14 or RS components and grab a few pairs.So in your opinion is the plug being stackable 100% needed? Seems pretty useful.

author: Ian.M
author_rank: Super Contributor
timestamp: June 06, 2024, 05:52:47 am
content: Not 100% needed, and you don't need *ALL* your banana leads to be stackable, but once you have a few pairs of stackable banana leads, you'll wonder how you ever managed without them!

author: EPAIII
author_rank: Super Contributor
timestamp: June 06, 2024, 06:39:30 am
content: If you buy from professional sources like DigiKey, Newark, Mouser, and others, they sell parts with well known brand names that have data sheets available for each item they sell. You can examine the specifications in those data sheets to see if the item meets your needs. And if you do not find the information in those data sheets, you can contact the manufacturers.Places like AliExpress sell cheap, NO NAME versions of the parts. Those versions often are so poorly made that they do not survive even the initial assembly process, like soldering or tightening screws/nuts or other common assembly devices. E-Bay and Amazon are also questionable sources.Element 14 seems to be a part of Newark. I am not sure how it differs from Newark itself.Quote from: AVGresponding on June 04, 2024, 04:04:52 pm

author: tooki
author_rank: Super Contributor
timestamp: June 06, 2024, 08:08:37 am
content: Quote from: confusion on June 06, 2024, 05:17:23 amThere are situations where you don’t want stackable, because of the higher risk of inadvertent contact (with a finger, or with a wayward wire or tool). For example, when probing mains inside the distribution panel. (Think CAT III or IV in multimeters.) This is why multimeter probes, for example, almost never have stackable plugs.For everything else, stackable is usually desirable.

author: confusion
author_rank: Contributor
timestamp: June 06, 2024, 09:26:12 am
content: Quote from: tooki on June 06, 2024, 08:08:37 amThat makes a lot of sense. Are there a lot of commercial alternatives for push-fit connectors like bananas? They seem to be pretty good at what they do.I'm a bit of a dumbarse sometimes so kind of like the idea of having a couple of different leads in the draw, one for serial connection and one for parallel when working with my benchtop PSU. Harder to screw things up after a few beers have inspired me to get back to job

author: reboots
author_rank: Regular Contributor
timestamp: June 06, 2024, 06:22:24 pm
content: Quote from: confusion on June 06, 2024, 09:26:12 amBanana connectors max out around 10A, depending on the manufacturer. Above a few amps it's prudent to use crimped wire lugs under the binding posts instead.Banana plugs are great at what they do. Typically you'll see banana for moderate AC or DC voltages, BNC for RF and small signal, and various types of clips and grabbers for everything else. There are also pin jacks and 2mm banana plugs, but they're not as commonly found on bench equipment.I use Pomona grabber clip patch cords, which are very good quality but might be on the expensive side for a home workshop.https://www.pomonaelectronics.com/products/patch-cordsPast an amp or so, alligator clips are more appropriate than grabbers. I prefer Mueller Electric "Popper" telecom clips, which are much higher quality than generic alligator clips and have multiple built-in contact methods to choose from: insulation-piercing spikes, bed of nails contacts, etc.https://www.muellerelectric.com/products/category/clips?opts=334

author: tooki
author_rank: Super Contributor
timestamp: June 06, 2024, 07:05:38 pm
content: Quote from: reboots on June 06, 2024, 06:22:24 pm10A? Try 32A — that’s what the beefiest 4mm banana plugs from Stäubli and Hirschmann are specified at. Even their more basic ones are mostly 16A — others with lower ratings are because they’re made for thin wire that can’t handle that current.Of course, for 32A you have to attach beefy wire. You don’t wanna do that with 18AWG!(Bear in mind that the lantern-style contact design is one of the highest-performing designs that exists, so it’s used for various high-end industrial connectors at high currents, while being tolerant of vibration or misalignment. They’re often a bit “invisible”, in that the lantern springs are often on the inside of the female contact, mating with a simple solid male pin. You can even buy the bare lantern springs in strips for making custom connectors!)

author: richard.cs
author_rank: Super Contributor
timestamp: June 08, 2024, 02:23:05 pm
content: Quote from: confusion on June 04, 2024, 07:18:59 pmI've been through various options over the years, but I have pretty much settled on the Anderson PowerPole in the 15/30/45A size (all intermatable). Reasonably priced, with cheap clones available for non critical uses, range of contact sizes, genderless. Not inherently waterproof, but available with rubber boots, etc. and seem to be pretty good outside. I use them all in a 2-pole config to the amateur radio standard, but they can be used individually like MC4, built up into large assemblies, or keyed differently by rotating one pole.A lot of people seem to use XT30/60/90 for general DC stuff but I'm not really a fan.