Test Equipment Anonymous (TEA) group therapy thread

[beanflying]

I still use DB9 and 15's for R/C wing connectors and have used them in the back of my Reference power supply for outputs recently. Data or sub 500mA low voltage, metal to metal connections with or without without screws they have a lot going for them.

I am in denial about USB C in particular where I see idiots trying to push high wattage charging through them. Just because it says it can be done doesn't mean it should be

[bd139]

Yeah I don't fancy that myself. This thing has a 30W charger which is plenty especially seeing as its predecessor's 85W charger exploded on me. Takes about 2 hours for it to fill up. After that it runs for 12 hours. Amazing!  Mind you 90% of the thing is batteries.

Things have come a looooong way since tubes stuffed full of cylindrical SLAs like early portable test gear that you got 4 hours out for the 10Kg pack!

[GregDunn]

I found a couple of nice AMP connectors which I used as power connections to my preamp and stereo crossover project; no chance of plugging them in wrong or having them broken by a careless bump.  Plus they daisy-chain the ±15VDC between modules so I can add more to the system at any time.  Sadly, they probably cost upward of $100 brand new...

I think the main problem with any USB connection carrying power is whether the cables are properly designed and wired, not the USB connector itself.  There are so many crap USB cables out there I would be nervous about any of them carrying power without knowing the construction quality.  The USB-C power delivery spec, if adhered to, ought to ensure a good safe power connection.

[bd139]

I've got powerpoles on all my amateur radio kit. That's the ultimate for me (mnem will disagree  ) . I've made up some leads for 4mm/powerpole and splitters etc. Use it for charging my three SLAs as well off bench supplies. It's turning into an obsession. I've switched my bench lights out for powerpoles as well so if there's a power outage, which happens way too often considering I live in a major city, I swap over a couple of plugs and I'm sitting there in the light in my corner with radio, lights.

Just need powerpole scope, kettle and fridge

You could tie a bear up with the USB-C cable that came with this. It's proper solid.

[beanflying]

I have been meaning to make a fascia adapter (3D printed) for these Deans Connectors with proper gold contacts below. I use a heap of them (genuine not chinese ones) over 20V and up to 80A.

Given the kwality of current USB chinesium wire USB C is heading for some meltdowns and fires I think.

[bd139]

Gah I remember those things from when I was playing around with RC cars. Was never sure if I got genuine ones or not sometimes. I had a couple of meltdowns which caused a bit of damage to my Yokomo MR4TC.

I like the powerpoles because they are hermaphroditic, totally enclosed and crimped. Typical set up for me. Some love of 3M inline fuse holders too. And cheap auto fuses

[beanflying]

We dropped Powerpoles maybe 25 years ago due to contact resistance issues, at the time we were running 20-25A on most of our 7 cell NiCad stuff and went to 4mm Banana's which had shorting issues if you did it wrong.

Genuine Deans still come in a separate baggy logo'd etc. This one below is also useful to over 5A toward 10 if you have to (genuine only).

[bd139]

Interesting. I am perhaps pushing 5A max through these at the moment so not entirely bothered yet until I need to be

[Brumby]

OMG - I thought you were supposed to use chains when driving in the snow....

[LapTop006]

I am in denial about USB C in particular where I see idiots trying to push high wattage charging through them. Just because it says it can be done doesn't mean it should be

It's not so bad, anything at a reasonable power is done above 5v, so the current stays at 3A until VBUS is 20v then (with cables marked safe for it) you can do 5A.

There's still plenty of messes with various chargers & devices not really meeting the USB-PD spec, but the fact I only need to carry one charger for my ThinkPad, MacBook & ChromeBook (not that I regularly carry all three), and it can also directly fast charge my phone, is a great improvement.

[Specmaster]

It was talking about those glorious Philips units. Then thoughts drifted to high end Teks with cursors

Edit: random whinge. USB-C still feels sooooo wrong:

Oh I see, said the blind man  Hmm, those philips units are a tad more modern and upto date than the Teks though, but on the down side they have fans

[beanflying]

I am in denial about USB C in particular where I see idiots trying to push high wattage charging through them. Just because it says it can be done doesn't mean it should be

It's not so bad, anything at a reasonable power is done above 5v, so the current stays at 3A until VBUS is 20v then (with cables marked safe for it) you can do 5A.

There's still plenty of messes with various chargers & devices not really meeting the USB-PD spec, but the fact I only need to carry one charger for my ThinkPad, MacBook & ChromeBook (not that I regularly carry all three), and it can also directly fast charge my phone, is a great improvement.

Done to a quality standard I suspect it is perfectly fine. Unfortunately recent history of poorly made cables and devices and the drive to the bottom price before all else isn't that end. 

[mnementh]

   I have been meaning to make a fascia adapter (3D printed) for these Deans Connectors with proper gold contacts below. I use a heap of them (genuine not chinese ones) over 20V and up to 80A.

Given the kwality of current USB chinesium wire USB C is heading for some meltdowns and fires I think.

HISSSSSSSSSSSS!!!

The only thing worse than SERMOS connectors is DEANS' connectors! A effing crash & burn just looking for a place to happen; I know from personal experience. 

Unshrouded contacts on a high-current connector are imbecility at its finest.     At least when SERMOS connectors are intact, they're shrouded... though it doesn't take much more than a sneeze while you're handling them to break that effing polycarbonate.

I know from personal real racing experience with both; I used to swear BY DEANS'... now I swear AT 'em. Same with SERMOS. RUN AWAY!!! RUN AWAY!!! 

DEANS' are fucking snake oil, man. Sure they MEASURE low; that's due to the higher contact pressure at which they operate. But covalent area is where REAL current is handled, and CNC Bullets beat them there every time. XT30 / XT60 / XT90 Anti-Arcing, HXTs otherwise.

Only place I'll use Deans' is on my floor sweeper. that's where they belong. 

mnem
*Juicy*

[mnementh]

I am in denial about USB C in particular where I see idiots trying to push high wattage charging through them. Just because it says it can be done doesn't mean it should be

It's not so bad, anything at a reasonable power is done above 5v, so the current stays at 3A until VBUS is 20v then (with cables marked safe for it) you can do 5A.

There's still plenty of messes with various chargers & devices not really meeting the USB-PD spec, but the fact I only need to carry one charger for my ThinkPad, MacBook & ChromeBook (not that I regularly carry all three), and it can also directly fast charge my phone, is a great improvement.

Done to a quality standard I suspect it is perfectly fine. Unfortunately recent history of poorly made cables and devices and the drive to the bottom price before all else isn't that end. 

I tend to agree... USB-C is a really forward-thinking, well-considered and ambitious standard. Unfortuantely, the race to the bottom will make it a total clusterfuck once reality sets in.

mnem
I'm wearing pants!!! 

[beanflying]

And yet you are wrong 

Exposed metal contacts apart from on the chargers which should drop off anyway without a load should never become live or it is being done wrong. The Fake Deans are horrid with high contact pressures (screwdriver job to unplug some) poor plating and don't like much more than 20-30A. Unless you trust a supplier to deliver the real deal in bags these days Deans are most likely fake. 

The XT connectors were not around when we started playing with the early brushless and LiPo's so Deans or 4-6mm bullets is what was used for over 80A. For me Deans are a Legacy and as I have wholesale access to the real deal I am not changing them out anytime soon on my mid powered stuff (30-50+ sets or cells?) .

[Neomys Sapiens]

I noticed eBay has entirely dried up for Christmas now. There's literally bugger all of interest there that is test gear related. You'd think everyone would be selling it now to try and get some extra cash in for Christmas but nope, dead!

Perhaps this is a sign I should be finishing some projects 

Totally not true over here. Lots of mid-range modern scopes over the last two weeks, R&S SMIQs being thrown at the crowd around 550.-, one guy disposing of a lot of RF bits all starting at 1.-, even chaseworthy multimeters to be had. Watch list full to the brim.

[mnementh]

And yet you are wrong     Exposed metal contacts apart from on the chargers which should drop off anyway without a load should never become live or it is being done wrong. The Fake Deans are horrid with high contact pressures (screwdriver job to unplug some) poor plating and don't like much more than 20-30A. Unless you trust a supplier to deliver the real deal in bags these days Deans are most likely fake. 

The XT connectors were not around when we started playing with the early brushless and LiPo's so Deans or 4-6mm bullets is what was used for over 80A. For me Deans are a Legacy and as I have wholesale access to the real deal I am not changing them out anytime soon on my mid powered stuff (30-50+ sets or cells?) .

When I was racing with them there were no fakes. I got rid of all of 'em after a set of Deans' connectors came half-unplugged in the last 3 laps of a race I was winning. The exposed contacts arced across a shock tower, burning it in half and causing a Bruckheimer-esquely spectacular and catastrophic end-over-end (counts varied from 10-16 flips) crash that ended in a small but exciting polycarbonate-body fire. I salvaged about 60% of my best, fastest and favorite 1/10 scale Dirt Oval race car; neither of us were the same after that, nor were my point standings which slipped steadily until I built new from the ground up.

So FUCK Deans', and fuck all the excuses for not flame-decommissioning them as they deserve. 

mnem
No quarter.

[beanflying]

Just because you didn't plug it together properly or had your lead under tension doesn't make them a bad connector 

In over 20 years of flying with Deans and using with BEC's to power the Rx's in most cases I am yet to have a set of big ones or the 2 or 4R's come apart (touch wood) this would result in more than a little devastation if it did.

[mnementh]

I double and triple-check the battery connection; it's part of my pit checklist. I take more than reasonable care.

None of that counters the fact they're selling BS. Real-world use proves it again and again; guys try to build race quads with them, the quads fly like shit because they're starved for surge current. You can see the voltage sag in the telemetry & logs. Replace those POS Deans' with XT60s or XT90s and BAM! a completely different beast.

Cheers!

mnem
Still juicy after all these years...

[beanflying]

For that sort of reason my two Trex 600's are running short 6mm Bullets not Deans, XT's are just a pretty wrapper for the bullets . Depending of what sort of measurement you use peaks are 2-3000W+ (so 100-150A) on these depending on the twit on the sticks.

[mnementh]

So, you know I'm right about Deans' being mostly fanboi-ism, but you just had to taunt the dwagon? 

Ehhh... AMASS makes a pretty good XTx0 connector; they listen to their customers and make products they ask for. Lightweight versions, bulkhead versions, anti-ARC versions. And they're all much cheaper than the alleged name brands, which half the time as you say... are knock-offs. I don't mind paying their prices for the "pretty wrapper", since I loathe unshrouded connectors.

The AMASS XT90 Anti-Arc are quite a bit more than that. 4.5mm CNC bullet connectors with a pre-contact that pre-charges the big electrolytic on your ESC(s) through a resistor to eliminate arcing. I've pulled 400A through a 4mm HXT pair through a carbon pile for ~30 seconds; they did get hot but didn't melt. I expect no less from these.

In Other News...

Welp, now we're gonna see just how good my little USB3.0 SD Card reader is. I'm doing a long format on a 32GGB card due to some "Fragmentation Errors" that popped up in the browser FW for this hacked 3DS 208in1 game card.

Looking not too shabby...done in the time it took me to type this post (and add an edit).

mnem
"Draco dormiens nunquam titillandus"

[bd139]

And yet you are wrong     Exposed metal contacts apart from on the chargers which should drop off anyway without a load should never become live or it is being done wrong. The Fake Deans are horrid with high contact pressures (screwdriver job to unplug some) poor plating and don't like much more than 20-30A. Unless you trust a supplier to deliver the real deal in bags these days Deans are most likely fake. 

The XT connectors were not around when we started playing with the early brushless and LiPo's so Deans or 4-6mm bullets is what was used for over 80A. For me Deans are a Legacy and as I have wholesale access to the real deal I am not changing them out anytime soon on my mid powered stuff (30-50+ sets or cells?) .

When I was racing with them there were no fakes. I got rid of all of 'em after a set of Deans' connectors came half-unplugged in the last 3 laps of a race I was winning. The exposed contacts arced across a shock tower, burning it in half and causing a Bruckheimer-esquely spectacular and catastrophic end-over-end (counts varied from 10-16 flips) crash that ended in a small but exciting polycarbonate-body fire. I salvaged about 60% of my best, fastest and favorite 1/10 scale Dirt Oval race car; neither of us were the same after that, nor were my point standings which slipped steadily until I built new from the ground up.

So FUCK Deans', and fuck all the excuses for not flame-decommissioning them as they deserve. 

That’s what happened to me. Connector burned up and ended up slamming the car at around 40mph into the barrier which wrote off most ABS parts on the front of it and the shell. The latter was fortunately rushed and just painted black so no major loss of artwork there!

[beanflying]

Never bothered with racing drones but based on the packs they run peak currents are going maybe get to 100A? Throw 3kg of Trex against the sticks on pitch and watch the needle spike

I am building up a powerplant for one of my big gliders at present 8S @ 80A (peak on the ground will be a bit more) gear drive Brushless so about 2.5kW for 6-10 second bursts. 3.6M (12') of composite going vertical at 150km/hr is about the numbers. as I am getting to old (smart & cunning) to lump around winches and truck batteries and play contests anymore. And no it won't have Deans on it 

And who me taunt a Dwagon 

[mnementh]

Race quads are using power supply designs around a 150A continuous, 200-300A surge current draw platform right now. We're talking 4 motors in the 1-2KW burst range: 2204-2400KVs on the $99 special, 2306-3200KVs on a race build thats running between 4S-6S. Most of the time you aren't actually USING that capacity... it's only in hard punchouts (racing) and really fast corrections where you can actually hit be trying to change speeds against the air pressure you just created. Loading in these circumstances is VERY dynamic... you can actually be worse than a dead short, fighting heavy reverse EMF for a brief time; several hundred milliseconds is common.

The reason these brief times are so critical to flight is not how fast YOU are... but how fast the FC thinks and makes adjustments to do what you ask it to. So yeah... it's weird to see, but 1300-1500mAH packs with 12Ga wires and XT60/XT90s are not uncommon. It's ALL about making the lowest resistance connection so you aren't starved when that FC says "JUMP MOTHERFUCKER!!!" to an ESC. If it's starved, your quad feels sluggish and wobbly. ESPECIALLY flying FPV.

TREX Draws more continuous current, but governed motor; but you're not making drastic changes to motor speed instantaneously like we are. Surge current is our bane, like I said.

mnem
*Currently undercurrent*

[beanflying]

Fairly constant RPM on the head but punch on the current non the less caused by the pitch changes during aerobatics are up there. Throwing 3kg backward and forward like this uses ERGS+ I wish it was me but alas I am a mere mortal unlike Szabo who is a freak this is 6 years ago and a 'test flight' too btw

Most likely 6S 5000mA at the time and would have been near flat at 4minutes.

https://youtu.be/DU8o3djhvSU