Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

  I just "accidentally" bought a Solartron 7150 (I was expecting to get overbid).

Please excuse me while I go and build more shelves...   

So, it was you, I was hoping that someone from here got it, I was out shopping and missed it.

[Cerebus]

So, it was you, I was hoping that someone from here got it, I was out shopping and missed it.

It takes some of the pain away knowing that if outbid by a recognised TEAer you can up the level of piss taking of them as partial compensation for your loss. 

The font colour I use is an affectation that I make no apology for

Perhaps, but it's a broad target for some retaliatory piss-taking. 

[bd139]

Set them all to 2n3055's 

Edit: I still really like the HP 6236B design. Almost the same as the Harrison design 30 years before. Almost the same as the Keysight version 30 years after. Thats when you know you got shit right! Also not a whole lot of loop compensation going on so it makes sense:

What I do not understand: why using a PNP power transistor as the series regulator (Q1). What is the advantage? I've learnt years back, that the PNP transistors are not so good spec-wise as the NPN ones. Same is said about the LM78XX vs. LM79XX. Lots of people dislike the 79XX because of their tendency to oscillate.

 

Well it's more I picked a bad example here  . It's a dual rail power supply in this case so there's a matching NPN on the negative rail and the supply is symmetrical and tracking. If you do it this way round it makes the tracking and the reference supplies easier to work with I think. If you look at the block diagram of a more sensible single-rail HP 6284A it has am NPN pass element:



As for the 79xx, I'm not sure why they even exist. You can just two floating 78xx units and not get that pain. Well I can see why they exist really as if you're muntzing and have a mid-tap transformer then it saves a few cents. Such is life. As per the datasheet though as long as you put a decent 25uF+ capacitor across the output it'll be perfectly stable.

Set them all to 2n3055's 

Nah, use a real man's transistor 2SC5200; 250V 17A and current gain that doesn't disappear when you start pushing more than an amp through it.

(Attachment Link)

(Attachment Link)

Edit: I still really like the HP 6236B design. Almost the same as the Harrison design 30 years before. Almost the same as the Keysight version 30 years after. Thats when you know you got shit right! Also not a whole lot of loop compensation going on so it makes sense:

Indeed. I think it's well known here that I'm a fan of HP/Harrison era supplies and their natural HP successors.

That 2SC5200 is a pretty hefty bastard isn't it!

The 2N3055's are easily startled, but soon they'll be back, and in greater numbers.

[WastelandTek]

holy current batman

[BU508A]

That 2SC5200 is a pretty hefty bastard isn't it!

I do like the MJ15003 (NPN) and MJ15004 (PNP) combo.
20A, 140V and a Ptot of 250W. 

The 2N3055's are easily startled, but soon they'll be back, and in greater numbers.

Holy Moly! That's a real 2N3055 grave! 

[Zucca]

chuck norris bed heater

[BU508A]

holy current batman

[McBryce]

That 2SC5200 is a pretty hefty bastard isn't it!

The 2N3055's are easily startled, but soon they'll be back, and in greater numbers.

That would be perfect for comparing thermal cameras when it's running. Must give a crazy picture.

McBryce.

[xrunner]

The 2N3055's are easily startled, but soon they'll be back, and in greater numbers.

Looks like one row was fighting the evil Darth 2N3055 and just disappeared when the time was right. 

[mnementh]

I wanna shine that thing up to a mirror finish with Mother's... then hang it on a wall connected to one 25mm LED that blinks on randomly.

mnem

[bd139]

I reckon you'd be better off with a 25m LED with that array 

[Wolfgang]

That 2SC5200 is a pretty hefty bastard isn't it!

The 2N3055's are easily startled, but soon they'll be back, and in greater numbers.

That would be perfect for comparing thermal cameras when it's running. Must give a crazy picture.

McBryce.

Reminds me of my days at university. A colleage of mine had to develop a motor drive for a hefty DC machine controlled by a novel regulator in an early microcontroller. After every small programming mistake, all the 2N3055 caps would pop off (loud !!) and the poor chap had to replace all of them. 

[mnementh]

*currently brewing tomorrow's iced tea*

You can take the boy out of Texas/New York but you really can't take Texas/New York out of the boy can you? There he is in the Frozen Hell Hole of Hoth in winter and he's still drinking iced tea.

Damn Skippy!!! 

It gets worse... as with my coffee, I tend to like a strong brew. As in letting it steep 3-6 hours or even overnight; like normal people do to compensate for the dilution effect of added ice. But I NEVER pour it over ice... I drink it that way right out of the fridge.

mnem
*twitch... twitch... twitcha-twitch...*

[mnementh]

I wanna shine that thing up to a mirror finish with Mother's... then hang it on a wall connected to one 25mm LED that blinks on randomly.

I reckon you'd be better off with a 25m LED with that array 

*cackle*

That would spoil the joke, but yeah; I imagine that array draws more than enough idle current to light a couple dozen 25mm LEDs. 

mnem
*the Devil's hands are idle playthings*

[AVGresponding]

The font colour I use is an affectation that I make no apology for

Perhaps, but it's a broad target for some retaliatory piss-taking. 

I started using it when I was making guides for guildies for the MMORPG I play; some of them were a bit dyslexic and it seemed to help them read the stuff.
It just kind of became a habit eventually, half the time I don't even use the drop-down menus, just type my own containers...


I once made a DC load out of an old UPS inverter output driver, had about 50 2N3055s on a loooong (they were mounted in a single line!) heatsink.
Had to cut the thing in half to make it practical for mounting in a portable case (we were commissioning theatre lighting systems for the new MAFF (now DEFRA) labs in York) and run some serious airflow to keep it from going thermonuclear, but it was good for around 3kW iirc.


EDIT: Goodbye to Larry Tesler and Heather Couper. Shitty week for the nerds   

[Cerebus]

The 2N3055's are easily startled, but soon they'll be back, and in greater numbers.

I used to use a Studer  A80 16 track 2" tape machine that had several heatsinks that were mini versions of that loaded with 2N3055s for the various motor drives. They were temperamental to say the least - there was a weak point in the tape tension/fast-wind servo design that meant that the servo was prone to lock up if one of the 2N3055s went short circuit. If this failed, when you got to the end of the tape instead of quietly spooling it off and stopping, the left tape hub went into full reverse current and the right tape hub went into full forward. This resulted in the reels cranking themselves up to impressive speeds, and as at this point one reel had ~10-15lb of tape on it, it soon got quite scary in terms of pure angular momentum.

First time it happened in front of me I was on my own just reeling off a tape so that we could put the second half of the session we were mixing onto the machine. The others had gone for coffee. I thought I'd broken the machine and the only way I got it to stop was hitting the master power. I thought the studio manager was going to keel-haul me, I was about 17 at the time. He just shrugged and grabbed the schematics, a Fluke and his tools. 

One of these beasts:

[xrunner]

Updates on my MOSFET order from China dealer - just so you guys know that I'm really sweet. 

China Seller:

Hello my dear friend,

Sorry for trouble again. I feel sorry for it，
Because of the situation of virus in Shenzhen is not good,government need to verify the market and avoid the crowed people，we get info the market will be opened on March 7, then we should could ship them out.but that is the latest infomation.maybe be delayed again.
so could you wait then?
if not,how about we refund you all the money and cancelled the order,
waiting for your reply, thank you and hope your understandin

Me:

No problem, thanks for keeping in touch, just wait until you can ship them.

China Seller:

thank you,
you are the sweetest ~any update,we will let you know~
wish you and your family a happy life and work well.

[bd139]

That's actually cheered me up a bit after spending the entire day fighting Kubnernetes

[nfmax]

That's actually cheered me up a bit after spending the entire day fighting Kubnernetes

Thwack it over the head with the steering oar!

[bd139]

Hahaha . Apparently I can't even spell Kubernetes properly by the end of the day either 

[BU508A]

That's actually cheered me up a bit after spending the entire day fighting Kubnernetes

We've launched VMs, because we wanted to solve the problems with the distributions.
We've launched Container, because we wanted to solve the problems with the VMs.
We've launched Docker, because we wanted to solve the problems with Container.
We've launched Kubernets, because we wanted to solve the problems with Docker.

And now we want to launch Serverless, because we want to spend more money to Amazon. Oh, wait, to solve the problems with Kubernets.

Source (in German):
https://blog.fefe.de/?ts=a0ee2157

And here is a nice deployment diagram:

[AVGresponding]

If the buckets were tradies (blokes/lasses with tools), and everything else was managers, that would be a diagram of how Facilities Management works in local government.

[bd139]

Yes. Local government is full of cronies, slack arses, pension vultures and incompetents from direct experience (sued them). There are a few competent people who somehow manage to elevate themselves to a position to prevent as much damage from the zombie hoards. NHS is the same (out of court settlement there). Most of the good experiences these days are purely luck 

That's actually cheered me up a bit after spending the entire day fighting Kubnernetes

We've launched VMs, because we wanted to solve the problems with the distributions.
We've launched Container, because we wanted to solve the problems with the VMs.
We've launched Docker, because we wanted to solve the problems with Container.
We've launched Kubernets, because we wanted to solve the problems with Docker.

And now we want to launch Serverless, because we want to spend more money to Amazon. Oh, wait, to solve the problems with Kubernets.

Source (in German):
https://blog.fefe.de/?ts=a0ee2157

And here is a nice deployment diagram:

That's probably still more fun that arguing with postfix and dovecot and LDAP from experience which basically involves doing all that via several meta-languages in different config files 

But really it's about Mr Bezos at work:



Also SES (Shitty Email Shit) sucks. Delivery problems galore and you can only unclog it per user by entering something in a captcha encrusted turd of a form.

As for containers, I entirely agree with the concept as long as they are bare metal otherwise all you're doing is hiding the layers of problems you mentioned . Every time someone drags an entire windows install or a linux distribution with them they are morons. Go or .Net Core on top of docker on a bare bones image is pretty nice to work with. Just tell kubernetes to give you 20 of that service and 15 of that service and off it goes and wires itself up. If a node goes down it deals with it automatically rather than having to find an operations dude who doesn't stumble in and blow the entire hypervisor network out while trying to drain the duff nodes from the balancer 

But it's WEEKEND now so fuck it all. Hamfest and a nice countryside walk in the pissing rain on Sunday and another week closer to being able to get a house in the middle of nowhere full of oscilloscopes with a moat around it

[WastelandTek]

If the buckets were tradies (blokes/lasses with tools), and everything else was managers, that would be a diagram of how Facilities Management works in local government.

Looks like we might have to lay off Andre

[med6753]

That 2SC5200 is a pretty hefty bastard isn't it!

I do like the MJ15003 (NPN) and MJ15004 (PNP) combo.
20A, 140V and a Ptot of 250W. 

The 2N3055's are easily startled, but soon they'll be back, and in greater numbers.

Holy Moly! That's a real 2N3055 grave! 

Yikes!