Test Equipment Anonymous (TEA) group therapy thread

[AVGresponding]

At long last, a NEW Photonicinduction vid!!!

[ch_scr]

Repaired something today. Left it on the bench to burn in. Checked in a while later, only to find the device turned off, and the power supply in CC mode. Something was strange. Unplugged the device. Supply still in CC, and I realised: it's in CC and shows no current on the meter. Repaired device now on another supply, seems still good. New box on the repair bench 

[Cubdriver]

Repaired something today. Left it on the bench to burn in. Checked in a while later, only to find the device turned off, and the power supply in CC mode. Something was strange. Unplugged the device. Supply still in CC, and I realised: it's in CC and shows no current on the meter. Repaired device now on another supply, seems still good. New box on the repair bench 

A 'graceful' failure, at least - much better than the supply announcing its demise with a heavy cloud of Eau de Allen-Bradley, as one of mine did last summer after shorting a pass transistor when it was left unattended for five minutes after working flawlessly for hours while I was nearby...   

-Pat

[med6753]

Repaired something today. Left it on the bench to burn in. Checked in a while later, only to find the device turned off, and the power supply in CC mode. Something was strange. Unplugged the device. Supply still in CC, and I realised: it's in CC and shows no current on the meter. Repaired device now on another supply, seems still good. New box on the repair bench 

A 'graceful' failure, at least - much better than the supply announcing its demise with a heavy cloud of Eau de Allen-Bradley, as one of mine did last summer after shorting a pass transistor when it was left unattended for five minutes after working flawlessly for hours while I was nearby...   

-Pat

A perfect example of why I never leave anything on the torture rack unattended. I've had failures but luckily no smoke. 

[BU508A]

Murphy is everywhere, especially where you least expect him. 

[Cubdriver]

Repaired something today. Left it on the bench to burn in. Checked in a while later, only to find the device turned off, and the power supply in CC mode. Something was strange. Unplugged the device. Supply still in CC, and I realised: it's in CC and shows no current on the meter. Repaired device now on another supply, seems still good. New box on the repair bench 

A 'graceful' failure, at least - much better than the supply announcing its demise with a heavy cloud of Eau de Allen-Bradley, as one of mine did last summer after shorting a pass transistor when it was left unattended for five minutes after working flawlessly for hours while I was nearby...   

-Pat

A perfect example of why I never leave anything on the torture rack unattended. I've had failures but luckily no smoke. 

I'd built a pair of resistive dummy loads to test a new power supply design for a project at work, and wanted to burn them in and make sure they wouldn't overheat before sending them out to CA.  The first one sat and cooked happily for several hours with me next to it doing other work on the computer.  Hooked number two up and it was cooking merrily away, too.  Got up for less than five minutes to hit the head and get a cup of coffee.  Came back to a cloud of smoke.  God damned Murphy, that Irish bastard!  He had to strike in the few minutes over several hours that I was away.  (And of course to add some salt to the wound it was mid summer so the windows were shut and I had things nicely air conditioned, then had to vent my nice cool air out to get rid of reduce the stench of charred G10 and wirewound resistors.)

-Pat

[Specmaster]

No TEA here today. Had to run errands before it got too hot and now inside domestic stuff such as sweeping, vacuuming (Hoovering), dusting, etc. It's noon here and temp is 90 F (32 C) and rising. Of course the A/C is on and it's a comfortable 75 F (24 C) in here. 

I may jinx myself for saying this but the A/C in the 2004 Honda Civic has NEVER been recharged and still works a treat after 17 years and 192,000 miles (308,994 km).

Either tomorrow or Wednesday I will be diving back into the Type 547. Oculus has provided me with some internal pictures of his functional Type 547. I have a suspicion that there was a prior attempt by a Gorilla to repair my scope and of course screwed it up.     

Thats strange you should mention the AC in the Civic because today I had mine recharged. I thought last week that it was not quite as cold as it once was, so I did some on-line research, and it seems that most cars will leak about 10% of the refrigerant annually and that it is recommended to have it checked and topped every 2 years to keep it at optimum efficiency. Mine has not been touched in 8 years since new, so I thought it might need it doing. It cost £39 at our local Tyre fitters and would have cost £150 at the main dealers. Is it colder now, yes I think it is but in honesty, without checking the before and after temps, I can't be sure. One thing I do know though, I certainly could not go back to having a car with no AC in it now. I'd end up as a big puddle in the footwell 

[mnementh]

From the ALL THE LITTLE FIDDLY-BITS Dept...

So... the last few days, I've been pressing the boundaries of WAF and Type 2 JENGA; the FatBike has been up on tables in the LR  (poor wife & kids on the far end of the couch to be able to watch TV around the damned thing, me cussing whenever I dusted a knuckle or burned myself grinding/soldering/friction-ed against something that was turning... we all know the drill )  for all the "little fiddly-bits" tinkering needed to make a "Fitzall eBike Motor Kit" actually fit.

I bought this kit after the 26" wheel & hub motor kit turned out to be wholly unsuitable; the weight of that thing is just ridiculous for a bike one intends to actually pedal most of the time. My interest is just to have something that can get my fat ass home if my bum knee decides it has had enough for the day and locks up on me. 

Fortunately the project is mostly done now and the beast back on the floor; a little Widlarizing blunt-force metal bracket rehabilitation here, a new 10mm thick 3DP sprocket spacer there, add a fistful of washers and we're at the point of actually starting to put things together.


   

First up, I had to completely dismantle the gearbox on this motor unit; as it came the power wires exited the motor in exactly the wrong direction, and of course, I needed the ~180mm difference that rotating the motor assembly on the casting represented. That did give me a good excuse to peek inside & take a pic for all y'alls... actually, for CAD$130, this motor and gearbox (plus it came with speed controller and throttle assembly) is quite a lot of precision manufacturing for very little money. Gear ratio is approximately 10:1 ; motor is rated ~3300RPM@36V with final output ~330RPM.

Those of you with a keen eye will notice there's something a bit funny aboot the sprocket here; it is actually a one-way sprocket meant to go on the wheel of a fixie, with a special hub to mount it to a keyed shaft. This is actually what makes this kit worth every penny; it means that you never have the pedals turning under motor power like with some kits, nor do you have the motor dragging on you when pedaling. All in a nice tidy little package that weighs ~2kg with the mounting plate.


   

With the motor/gearbox finally all back together, it was time to address the problem-child sprocket; the kit also comes with a sprocket, but it is one of those horrible "sandwich the spokes between plates and bits of belted rubber" things to be able to go on as many different bikes as possible. The same manufacturer also makes a gear meant to bolt to the hub under your disc brakes; as I have exactly that kind of wheels, I sprung the CAD$15 to get that too. Problem was... it is pretty cheaply made and full of burrs and a bit too thick and none of the chains I had wanted to ride properly on it.    So a little Dremel abuse followed by painstakingly hand-deburring every fucking tooth on the sprocket, and now we have a sprocket that runs gravity-feed smooth. 


   

Once it all came together, and with several trial/error fittings to get the stack of washers on the axle right for the required brake rotor offset, sprocket alignment is pretty close. Not perfect, but good enough for a trial ride to see if this iteration is going to serve. If it works and the chain doesn't grind under load, I'll order hub adapter kits (they are available in 3mm & 5mm widths) to get machined aluminum in place of that 3DP spacer and washers. Then, I can adjust the motor angle by placing a few washers between the casting and the mounting plate.

Of course, there's always the parts you buy but you DON'T use that wind up left over... fortunately, I was able to "steal of a deal" on most of my extra bits on crazy clearance sale items from Amazon & Wally World. I found some 24V/500W speed controls being blown out on Wally World for CAD$11 each; they were supposed to come with thumb throttles but only one did.  The sprocket I used was on half-price too; part of why I didn't mind having all this left over. Total extra expenditure above the $130 kit was ~CAD$35. I'm pretty sure I could blow it all out pretty quick on Kijiji, except I think I wanna revisit the scooter... 

The 24V kit with thumb throttle wound up paired to the 36V-rated motor above, as my first trial is going to be with one of my 6S Kobalt Drill/Impact Driver batteries, and I need to match the ESC's LVC to the battery. I'm hoping that underdriving the motor will keep the current draw within the limits of the BMS in the pack even carting me around; I've drawn almost 20A from one of these before when powering my LiPo charger in motor test mode. 



With the thumb-throttle, ESC and battery in the bag, the whole thing adds less than 5kg to the bike. I think that's a more than fair tradeoff for my intended purpose.



mnem

[mnementh]

Repaired something today. Left it on the bench to burn in. Checked in a while later, only to find the device turned off, and the power supply in CC mode. Something was strange. Unplugged the device. Supply still in CC, and I realised: it's in CC and shows no current on the meter. Repaired device now on another supply, seems still good. New box on the repair bench 

A 'graceful' failure, at least - much better than the supply announcing its demise with a heavy cloud of Eau de Allen-Bradley, as one of mine did last summer after shorting a pass transistor when it was left unattended for five minutes after working flawlessly for hours while I was nearby...   

-Pat

A perfect example of why I never leave anything on the torture rack unattended. I've had failures but luckily no smoke. 

I'd built a pair of resistive dummy loads to test a new power supply design for a project at work, and wanted to burn them in and make sure they wouldn't overheat before sending them out to CA.  The first one sat and cooked happily for several hours with me next to it doing other work on the computer.  Hooked number two up and it was cooking merrily away, too.  Got up for less than five minutes to hit the head and get a cup of coffee.  Came back to a cloud of smoke.  God damned Murphy, that Irish bastard!  He had to strike in the few minutes over several hours that I was away.  (And of course to add some salt to the wound it was mid summer so the windows were shut and I had things nicely air conditioned, then had to vent my nice cool air out to get rid of reduce the stench of charred G10 and wirewound resistors.)

-Pat

Murphy never sleeps.

mnem
And she has puppies.

[tautech]

Those of you with a keen eye will notice there's something a bit funny aboot the sprocket here; it is actually a one-way sprocket meant to go on the wheel of a fixie, with a special hub to mount it to a keyed shaft. This is actually what makes this kit worth every penny; it means that you never have the pedals turning under motor power like with some kits, nor do you have the motor dragging on you when pedaling. All in a nice tidy little package that weighs ~2kg with the mounting plate.

Called a sprag clutch. 

[mnementh]

Those of you with a keen eye will notice there's something a bit funny aboot the sprocket here; it is actually a one-way sprocket meant to go on the wheel of a fixie, with a special hub to mount it to a keyed shaft. This is actually what makes this kit worth every penny; it means that you never have the pedals turning under motor power like with some kits, nor do you have the motor dragging on you when pedaling. All in a nice tidy little package that weighs ~2kg with the mounting plate.

Called a sprag clutch. 

Naaaahhh... edit: the most common sprag clutch is a roller bearing modified such that in one direction the rollers cam out and jam against the bearing surface and it locks up. We "whirry little flying thing" wingnuts use them in the drive gearing on our model helis.

These are just like any other bicycle gear cluster, with ball bearings and a separate ratchet & pawl mechanism inside. When the wheel freewheels, now I get that ticketa-ticketa-ticketa-ticketa sound in stereo, and I can hear it clearly as the ratchet in the 7-speed gear cluster on the other side operates at a different timbre & frequency from the one on the motor.

mnem
 

[mansaxel]

One thing I do know though, I certainly could not go back to having a car with no AC in it now. I'd end up as a big puddle in the footwell 

Summer 2019, we drove Stockholm-Italy and back. With a broken AC. It is still broken; the clutch needs adjusting. Problem is, the clutch is jammed between the compressor and a bulkhead, below a stack of power steering, alternator, and water pump. Citroên-level of inacessibility.

Noise is acceptable to 135 km/h with all windows open, so that was our Autobahn speed. Record temp was 47° C, parked, in Pisa.

Last week, I bought a new car instead, which has a working AC. It is better. We've had a few days of fantastic summer weather here, but yesterday afternoon there was rain and some thunder, and the rain has kept up overnight.

[Brumby]

... Problem is, the clutch is jammed between the compressor and a bulkhead, below a stack of power steering, alternator, and water pump. Citroên-level of inacessibility.

Sounds like the next level up from Volkswagen inaccessibility.  (I once changed spark plugs on a VW Transporter.)

[beanflying]

Until you have driven a Landrover in an Aussie Summer you don't know about hot in Cars. The Aluminium shell seems to sink all the heat inside and the firewall and gearbox tunnel would burn if touched So mine did spend a lot of time with the roof off but then Sunburn became the issue.

[Saskia]

No comparison to my (ex) Audi. It became so hot that the glas, wheels, gearbox melted ...

[Saskia]

Other news: anyone in need of a B450M ryzen board ? or a mini-ITX / mini-ITX slim board

Before I put in onto evilbay.

[vk6zgo]

Until you have driven a Landrover in an Aussie Summer you don't know about hot in Cars. The Aluminium shell seems to sink all the heat inside and the firewall and gearbox tunnel would burn if touched So mine did spend a lot of time with the roof off but then Sunburn became the issue.

Wyndham in the "Dry" 1967/early '68.

Stepped off the Fokker F27, & the heat "hit me like a wall".
Picked up my stuff & followed the other local PMG Tech to his Series 2 Landrover.

My first experience of these beasts----sliding side windows, & flip out vents under the windscreen were the sum total of ventilation.

Our main place of work was the HF radio receiver site on the massive rocky hill overlooking the old Wyndham town, where I met the Boss, & was told that a "Dept of Supply" Landrover of "my very own" was "on the way" on the Stateship.
The Boss & the other techie had real PMG ones, which were well maintained.

Anyhow, after a couple of days, we were off to Hall's Creek ---- a "short hop" of 370km, on, in those days,  a dirt road, (if you could call it a"road"!)

When it came to my turn to drive, I discovered that the brake & clutch pedals were (scalding hot) bare metal, with nary a spec of rubber to be seen.
As our "dress code" was pretty much "T-shirt, shorts & "thongs"(flip flops), you had to develop tough feet, or learn the art of driving in thongs!

When my LR  ("ZSM381") turned up, it was seriously dire--- the Dept of Supply had been using it for some unspecified job on the beach around Port Hedland, & it was crusty with salt, which had eaten through the "corrosion proof" aluminium bodywork.
When the "Wet" came, the cab leaked like a sieve!

[tautech]

In more other news....tautech is back in the enabling game now stock has finally arrived. 

Those that were following along might remember the radio fix in my SUV a couple weeks back where after removing the front seat to evict the Jap TV/GPS and then leaving the seat out so to be able to fit 245kg 1.835m³ of Siglent goodies and be able to get them home in one trip.
Well absolutely chocker was the SUV with 2 of the 20 boxes needing to be unpacked so to slip their contents into the last remaining spaces.
Just one more scope would've needed to be on my lap but that may have been getting really dodgy as there wasn't much elbow room as it was. 
Some pics attached for your amusement. 

[VK5RC]

Nice stash😁

[beanflying]

Things that make you go Mmmm 

[VK5RC]

I've been enabled, got one of fake nixie clocks, this one uses etched perspex numbers, stacked together with under-lighting by multi colour LED. USB C powered with battery clock cr2032 back up. WAF high👍

[tautech]

Nice stash😁

Yeah I splashed out some before Mar 31 end of year to get the bank balance down. 
30 various scopes, 4 SA's, 4 bench DMM's, 2 E-loads, 6 AWG's, 2 PSU's and a menagerie of other bots and bobs yet some is already spoken for and already must get more ! 
Still got a great stock of SDS2104X Plus now despite some have gone already and some here from the US will be pissed when they can only get stock of the 2ch models. 

But international freight is a real shit fest ATM and anyone thinking of using bulk freight need be prepared for substantial delays. A year ago such stuff was a breeze but not now and it's gunna get worse, much worse ! 

[Cerebus]

Picked up my stuff & followed the other local PMG Tech to his Series 2 Landrover.

My first experience of these beasts----sliding side windows, & flip out vents under the windscreen were the sum total of ventilation.

Not entirely true. There was a fair amount of ventilation through all the shut lines, quite a few of the bodywork seams and quite often through a hole or six in the floor (often deliberately made to allow water to drain away). 

[beanflying]

I've been enabled, got one of fake nixie clocks, this one uses etched perspex numbers, stacked together with under-lighting by multi colour LED. USB C powered with battery clock cr2032 back up. WAF high👍

Can you have a rough check sometime and see if it is based on a 1.5 or 2mm acrylic stack? Sort of on my list to play with a making single digit for a start sometime.

[mnementh]

   In more other news....tautech is back in the enabling game now stock has finally arrived. 

Those that were following along might remember the radio fix in my SUV a couple weeks back where after removing the front seat to evict the Jap TV/GPS and then leaving the seat out so to be able to fit 245kg 1.835m³ of Siglent goodies and be able to get them home in one trip. Well absolutely chocker was the SUV with 2 of the 20 boxes needing to be unpacked so to slip their contents into the last remaining spaces. Just one more scope would've needed to be on my lap but that may have been getting really dodgy as there wasn't much elbow room as it was.  Some pics attached for your amusement. 

Ehhh... just a typical drive to a rack & stack back when I had the ol' PT Cruiser... I'd have to wedge my clipboard between the seat and center console to keep the boxes from sliding over and knocking the shifter out of DRIVE.   

mnem
They took my thumbs.