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- เผยแพร่เมื่อ 16 ส.ค. 2024
- Mystery dumpster teardown time!
With the most amazing mechanical mains power switch you'll ever see!
00:00 - Playing Around
10:00 - Teardown
14:00 - OMG that power switch!
20:40 - PCB Lesson for noobs
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For every electronic hobbyist, throwing away such a beauty is a sin
I've thrown away more interesting stuff.
@@jope4009 barbarian! ;)
No its not. Otherwise we wouldn't find a teardown of it ;)
So true
Hell yeah
We used those in pharma research lab where we might have 20-30 environmental chambers that we needed to track and have permanent record of their temp and humidity for drug approval submissions. The dot matrix allowed you to print the drug number beside the trace and they typically recorded every minute or so. Folded chart paper was preferred because it stored in the paper file folders easier!
Thanks for sharing Sir
Yep, we used the yokogawa recorders, they look suspiciously similar.
These are still very popular in the pharma manufacturing industry for recording multiple temperature probes during steam sterilisation cycles of sterile filling machines.
Pharma manufacturers are audited annually by government regulators. And those auditors love their paper records.
I can 99% guarantee that if it came from a pharma site it will have been replaced with another newer dot matrix printer.
we used something similar in the 90's when we reconditioned & rebuilt diesel marine engines for winches/pumps/generators etc. They were used in gas & oil rig offshore installations & the criteria for acceptance was very tight & we had to produce evidence of temp monitoring for practically every component during the run in process. The units would have to run for in excess of 100 hours at set RPM & every facet of the unit performance had to be demonstrated else it was rejected & rebuilt even if it was brand new. This was a company called ARS limited Loddon, Norfolk UK.
I should add that the unit we used monitored & recorded vibration too & was part of the engines "passport".
for legal reasons back in the 90's companies wouldn't take disks they wanted hard paper copies. Guess it was the same with you, Rubus?
Leave it to Dave to see this wonderful electromechanical marvel and go "Ok that's cool and all, but wait 'till you get a look at the power switch!" :)
I remember this thing.. Used to have one for petroleum cracking. Each lead could tell you the internal temperature of the product at various stages (channels) of the process and it would plot each channel over time.
I haven't seen this mechanical solution on a simple power switch yet. However I do have an old Technics amplifier that uses the same type of ribbon for the input and recording selectors, which makes sense in order to keep cables short and thus noise out.
My old Marantz PM30 does this too for the input selection.
@@DaFritzla The PM66 has the same and I've seen it used elsewhere.
Yeah, seen this principle in audio devices, one had the guide as a part of the front panel and a piece of very flexible plastic went through it.
That was great...Just listened to your interview with Louis Rossmann, oh man, he really has become such a wonderful character - Just like our Dave!
I say that because I've watched him since he started and sort of feel proud for him, watching him grow into the person he is. Very gratifying to see.
We could tell you thought he was a good chap to have on. Was a great Amp Hour.
Thanks for this comment. I'll have to check out that episode now.
I wish I had a dumpster like yours...the only items in my dumpster look like bio-hazard waste.
You read "TC" as "temperature compensation", it's probably "Thermocouple" since it says "KIND" next to it and "K" on the other side.
Yep. THe TC can be changed to mV, and probably to few other things, depending on options in this things (some of them can measure Vrms to 250V, and currents, as well provide currents for things like strain gauges, etc).
I believe the two "B" terminals are for 3-wire RTD's. They have two wires going to one side of the sensor element so the machine can measure the resistance in the lead wires and subtract that from the total resistance. This gives the actual resistance of the sensing element for a more accurate reading.
As in the video, they are definitely thermocouples and not RTD. My guess is the 3rd terminal may be a shielding terminal for noisy industrial environments.
had 256 channel thermocouple scanners that sent an asc data string to process control modules for reactor controls, a supervisory cluster logged the data. The replaced what would have been dozens of strip chart recorders on walls.
Lots of operator screens built around the data
Came here to say this. Many devices have TC/RTD inputs, selectable in software.
@@JernD There are options in software to switch between thermocouples and other things. I am pretty sure it is for 3-wire measurements, or there is input isolation.
@@JernD The TC option as shown in the video will (probably) include an option for RTDs; labeled as RTD or Pt or some such. Worked with a bunch of old school DAQs at work a lot like this. That's almost always what the third terminal is for. Typically these things will just tell you to ground shielding to the negative terminal. I haven't seen many that give shielding it's own spot.
Those steel belts are fairly common in older receivers or audio equipment (input selector, speaker A/B selection...) but don’t know what it’s called
it's like a bowden tube, but flat?
Yes, in audio equipment is where I encountered one. It was the source selection switch. It had a rotary knob which transfered the motion to the sliding motion of the metal strip. Verry cool switch indeed.
@@pietpaaltjes7419 Agreed, I had a Denon amplifier in a school that I needed to isolate to one source. The other end of the belt thing simply unclipped!
Yup, I've seen them in old Yamaha "Natural sound" stereo amps.
@@jopjopjop The Marantz PM66 amp uses it too.
14:48 I don't remember what they are called, but I've seen almost the same type of transfer belt switch in certain HiFi units / radio tuners.
They used to use them for the multi-pole switches on the front panel, to reduce the amount of wiring around the chassis, and supposedly reduce the noise.
I guess it would be a type of "Bowden cable", but if you search for that, all you'll find are the tubes for 3D printers, or bicycle brakes.
Sylvania have a patent for a "Bowden Wire Switch"...
patents.google.com/patent/US3501975
Here's an example of a vintage amp that uses the same system...
audiokarma.org/forums/index.php?threads/distortion-in-my-denon.724190/#post-9802247
ElectronAsh True! I unfortunately can’t recall what brand, but I remember having seen both power switches and multiple
Position turning knobs that transmit to sliding switch with multiple
Positions.
I also have found this system in Old marantz Amps.
The roller appears to be the door catch.
D'oh, yeah, obviously.
Fun fact: you can average the signal (assuming it's not AC) by cutting it out and weighing it and dividing by the weight of a whole (full scale) piece of the same length. This is how they used to take the mean in the "old days".
The mechanical linkage to the power switch is very common in Japanese hifi components for switching inputs, filters, speakers, and more. Luxman really liked to use those linkages in their products.
back when I was a (late) teenager, I worked in a steelworks (although it dealt with other metals) briefly and we had versions of these things. I used to take the broken ones home to salvage parts from
I read the video description before watching the video: "With the most amazing mechanical mains power switch you'll ever see!" and I thought at first that it was just a very snarky reference to the fact that the power switch was inside the front panel. I was not disappointed when I saw what it was actually referring to though.
I used to use something like that back in the mid 90's, for temp logging on 10 Furnaces. Chart records were needed for QA audit trail purposes.
I'm sure the 19:50 guard ring warrants more than just a brief mention. Maybe for a future episode?
Have wanted to. But need a good experimental practical demo idea.
@@EEVblog Transimpedance something - High gain, huge feedback resistance? Light sensing, for example
18:36 that was nice, just pulled a card from a analog x-ray image processor and it has these LC filters near the DC-DC converter, at first glance I just wondered why the SMD capacitor was elevated. That card also has some really interesting input noise counter-measures, I will make a video about that.
I saw a similar LC filter (if not exactly the sames) in the rather modern design in a computer board from DNA sequencer.
Having everything pull out from the cabinet front means that anything can be replaced while the cabinet remains firmly screwed to a relay rack. If there are long service loops in the rear-panel input wiring, the entire electronics module can be pulled out for servicing without even undoing the wiring. Once it all comes out, you might be able to snap it all together on a table in front of the rack in order to troubleshoot. Slick!
14:57 my vintage Pioneer amplifier has input selector switches like that. Quite clever, I think. The actual switch sits in the back near the RCAs, but you get to twiddle it on the front panel.
Those ribbon switch extenders - all vintage audio gear (technics, marantz etc) uses them to drive input selector (on the back) while operated from the front plate etc.
Is it only me that sees something misaligned in the color ribbon when Dave tried to print something? It was going on the side of the carriage, not underneath it.
10:04 in the video is a very nice closeup of misaligned color tape and 1:48 is how it should look like.
Forget about misaligned... the tape is completely folded to the side where it's painfully stuck between chassis parts.
My early 90s Sony STR-D2020 receiver uses one of those sliding flat enclosed mechanical 'cables' to actuate the speaker selector switch - there's a rotary selector on the front panel and it drives a big enclosed slide switch on a circuit board that's mounted at the rear near the output terminals. It's a four position selector - A+B - Off - A - B
We used a similar box without the strip chart for performance testing of cooling towers. ours had temperature, pressure, humidity, and flow rates. The reason everything came out the front like that was many of them were mounted in portable cases not racks. Be well
That power switch is briliant. Also so flexible to use, makes you more flexible in design too.
Those flexible "belts" used on the switch i have never seen on power switches, but on input-selectors in home audio HiFi amps from the mid 80's. Very smart.
Yea,seen them a couple times in old HiFi stuff.I seem to remember seeing one connected to a rotary input selector on the front panel,that then ran down to a multi-position linear slide switch on the PCB. Rotary to linear conversion,Nifty.
@@PhattyMo exactly. I think I've seen that setup in old Pioneer/Technics from the mid 80s
They used to use physical switch cables like that in stereo receivers.
Many many years ago... Dave, how can you missed it? =))
@Sean m I made a comment in the context of the device in the video and deleted it because I realized that you were probably talking about stereo receivers, so here's that answer instead: Probably to reduce the amount of wiring needed considering that many of the switches were likely multi pole switches. Also, audio signals, and especially RF signals would be susceptible to picking up or emitting interference, which would be another reason.
@Sean m The strip is a purely mechanical way of transferring power to a remote switch, so the length of wire is eliminated.
@Sean m For a stereo receiver, it could be very useful for something like an AM/FM switch because you don't need to feed a RF signal all the way to the front panel. When disconnected, the wire would be a long unterminated transmission line stub, with a slightly unspecified length. Extremely bad for that particular use. For an audio signal, assuming two channels that can be routed to two places, you would have 6 wires and 12 points that would need to be soldered manually. Not counting auxiliary control signals. The cost would add up quickly.
Dave " this is an LCD adjust" also Dave " this LCD is rubbish" Well, adjust it then!
30 seconds later. Hello? McFly? 🤣
Yeah, I know - lol -. Being a mech eng I also saw the screws on the bottom straight away - lol -.
It was already optimally adjusted.
@@madmodders Nope, that was me adjusting the exposure on my camera to compensate.
Look like the backlight has failed if it ever had one.
You could reverse engineer that print head and we will have a printed ( Dave's floating head ) version :D
That fancy power button thingy is used in a plie of audio gear from the late seventies and eighties, for starters, my Marantz PM550DC from 1982 has a similar setup for its input selector.
These belt driven switches where used where it was neccesary to keep away mains wiring from sensetiv components. I've seen these in test equipment, for example in an HP 1664A logic analyzer. Also it was common to use these switches in high-end audio appliances. Therefore it was possible to keep wiring of your input selection rotary switch short, gaining low losses and high signal to noise ratio.
Well that mechanic power switch is basically a bowden cable
Came here to make sure someone posted this. I remember the term from the bowden tube on 3D printers.
@@JWH3 Bowden cables pull, Morse cables are bidirectional.
@@fluffyfloof9267 Stranded-core Bowden cables are typically only used to pull, but solid-core Bowden cables exist and are absolutely bidirectional - at least I certainly hope they are or every aircraft I've ever flown has had its throttle open by magic when I push the knob forward!
I used a Yokogawa Mult Point recorder which did have individual pens with a digital print head back in the early 90's Extremely valuable in the process industry !! I worked in a cement plant making the product. It was configurable to different type inputs ie temp or mV. Used the chart recorder to monitor timing in the process ie how long it took material to get from one point to another . This is important when making a blend of stone + Gypsum and other materials when setting PID values in the process controllers. Enjoyed the video brought back lots of memories :) Thanks Dave
We had something similar at work for PT100 sensors. It was used there to measure the temperature deviation within the our products over long periods of time.
Considering the date-codes on some of the pcb's, I think the missing memory were SUPPORT RAM from a previous spin. (they could have switched to control chips that, due to a larger amount of internal memory (compared to the control chips from the previous spin), had no need for support ram... but it might still be an optional extra)
Great teardown and that snake flat cable is use on my old early 90s Pioneer A335 amplifier but for source selection, 1 for input and 1 for output 👍
We tested a product at work at one point where the power button was behind a (cheap lockable) cover. Then again it only had I think a single switch outside the cover (it was “industrial”).
If you mount it in the rack you don't ned to unscrew all sensor terminals and take apart your rack (probably with more devices over and under recorder) this way, you can service it just from front side. So I say, its definitely built like that deliberatrely.
Equipment like this is often designed into industrial control systems for recordkeeping. Often regulations still require hardcopy records; my experience is with temperature logging for milk and egg pasteurization. The terminals are pretty standard for industrial controls. As for the difficulty of taking it apart, it's probably a deliberate design choice. The ones I worked with were both locked and sealed by the regulatory inspector during commisioning.
I have a little 8-channel temperature logging K-type interface. It's USB and comes with some pretty nifty software, But this one looks like fun and would stop the lab blowing away in a tornado.
in some manufacturing like medical or implants, the manufacturer have to keep a paper trail of all process, in my previous job we used this to record multiple Owens temperatures and operators use to check the recorder multiple times during operation sometimes a couple of days and write down the temperature in their forms and at the end, all different forms plus master form from the dot-matrix printer would archive for at least 25 years.
Re power switch: Bowden cable, even if it's not a cable. Not that uncommon in other applications.
Similar flat actuations are used in weaving machines, moving the gripper holding the weft into the shed.
The power switch seems to work the same way as the brake & gear cables on a bicycle. A flexible push-pull mechanism tightly constrained by a flexible housing.
That kind of front access layer cake design is common for rackmout/panel mount equipment.
The power switch connection is like a cable/rod hybrid, the flexibility of a cable but able to work in compression like a rod
Truly appreciate you don’t have a single ad on your videos, unlike many other hungry youtubers. .
Reminds me of how older Mitel phone systems were build. Modular and easy to do field replacements on.
The system that remote power switch uses. Is very similar to the teleflex style control cable used in the EC 130 and 145 helicopters. The only difference in the teleflex system. Is that the strip runs in ball bearings. Rather than in a plastic guide.
I love that card/backplane style design. Makes it more maintainable/modular.
Technics SU-V9 amplifer use that type of "snake"-connection for input selector.
Nice dumpster dive. Now Dave can take the temperture on Eevblog and Eevblog2 and log it in real-time!
I have seen that power switch ribbon in some big home stereos over the years because the put the switch back at where the AC mains voltage enters the stereo at the back of the device and also on some stereo mode select switches and speaker switches.
Saw something like this power button on an old Pioneer amplifier. It was used for the input select, which moved in steps and had stops at either end.
Terminals B and B probably for compensation wire for temperature probe
Still waiting on an actual _dumpster_ teardown.
I've seen that kind of mains switch mechanical extension before. Worked on som high-end Japanese HiFi amplifiers and they used that kind of thing for input selection. I meant that the low-level audio input signal path didn't have to go all the way to the front panel and then back again. Keeps the signal noise down. Always loved playing with them, something mesmerising about them. Love yur stuff especially test equipment tear-downs and repirs!
I’ve seen that power button setup before in audio amplifiers/receivers, sometimes used to convert rotary selector switch motion to operate a linear slide switch on the board.
Be sure to check the backup meter to know how much water is in the reactor.
Or knock the meter glass to release the stuck printer head like in "China Syndrome"!
I've just signed up on Utreon as well ... and I've added you as the referrer / person who told me about it ... just as I did with LBRY .... just in case there is some reward or something you can get as a bonus. Appreciate your hard work and great content and awesome sense of humour !! 👍
No referal thing, but thanks.
Some amazing stuff to salvage from this!
I've seen those remote switches on several home stereo products. This thing was designed to be serviced inside a 19" equipment rack. Disconnecting 90 wires to extract it, service it, then reinstall it, reconnect 90 wires to the correct terminals would be expensive.
The spiral thumbnail is awesome
There is one of those steel ribbons in my Kenwood Basic C2 pre-amplifier where it is connected to a rotating selector for the phono cartridge type and impeadence.
Used chart recorders for long term data logging with battery cycle testing. Great for long duration logging as power cuts etching don't wipe your data. Ribbon cartridges then became obsolete so retired them. Very robust and reliable for voltage and temp logging. Digital dataloggers just dont compare for some aplications. The text setup reports took a while to print though.
Who else thought Dave should have turned the LCD Adjust knob the moment he commented on how hard it was to read the LCD screen? At 21:22 there is indication that the encased inductor had its designator on the PCB but the board designer didn't take the packaging in to account and ensure the label would not get hidden under the part.
@ 26:12 That roller mechanism U didn't know what it does early on;...
The metal 2 x screw 90' Angle plate pushes into that to it hold it shut
Keeps track of a lot of things. Could be temp of a freezer that houses medicine or could be for any industrial use that needs a log record for another system.
I had a 1980's Techincs amplifier that had a similar style remote switch for the input selection and a/b speaker selection. but they were a 4 way turn switch that connected to a metal ribbon in a sleeve that went to the actual switches on the back part of the board close to where the switching needed to be done. Good idea as it means the signal paths across the circuit board can be kept as short as possible.
My 1987 Kenwood Basic C2 Preamplifier had the same type of steel/blue plastic sliderbelt inside for selection.
that would make for a slick network / audio rack
The rubber feet were probably to protect it from another device on top. Could be used for IC manufacturing with those temperatures. If you want to track an array of tube furnaces for example. At Uni we had a 5 tube wafer furnace and I could see wanting to track the temperature for a bunch of experiments with one of these.
That type of snake mechanism is common in Radio Control Models where you attach a servo to a flight surface, where you do not have a direct line from the control horn to the flight surface
5:07 Maybe so you can't turn it off accidentally
Nice old unit, I can imagine them in factories monitoring machinery 24/7. Outdated now. If you watch HVACR Videos where they repair air conditoners, you see him placing little wireless temperature, pressure and airflow sensors in various places in the air-con unit, and then looking at all their readings simultaneously on a tablet (talking to all the sensors via bluetooth). Makes diagnosing faults so much easier!
The mechanical remote switch actuator is used in many audio gear, my Kenwood M2 power amp has one for speaker/load selection.
A 1990s Sony hifi amp I had used that same power switch mechanism for the input/output switches. Got slightly misaligned over time so not an ideal choice for switching multiple positions I guess.
The power switch snake is just a flat version of a bicycle brake cable.
14:45 Yes in a Philips 22AH386 from 1978 :) old school Philips audio amplifier.
This made me think of the interesting plotters that Westpak used on their thermal chambers when I went there for some testing. It uses like a round paper card and plots on it as it rotates around.
That 68k board would be a perfect hobbyist board. I know of a guy at our local retro-computing meetup that built a 68k board from scratch that runs an 68k BASIC he programmed into the eprom and has a serial terminal on it. Or potentially uCLinux.
The Sony F410R amplifier also uses a "ribbon" system like the power switch from its "rec out selector" The ribbon looks identical and likely is from the same company.
I misread the title a little and it gave me an idea.
What about, for your 1M subscriber special, tearing apart one of the dumpsters you keep pulling gold out?
On some car tests we used up to 200 channels logging
Apparently you can squirt the ribbon cartridge with WD40 to rejuvenate the ink?
A beautiful piece of kit ... a shame not to find some use for it ... way too good for landfill or scrapping ... Thanks for the tear-down.
My old pioneer amplifier used switches exactly like that for channel and recording input selections
I think I have a such ribbon mechanical switch in an hifi amp as far as I can recall (these thing doesn't need to be serviced often...)
I wish we could have seen the beast print some stuff! I'm totally addicted to dot matrix printer noise.
I can see a few components that I would like to salvage on those boards. Nice find.
I'd say it was from the days when we were transitioning from old electromechanical chart recorders to fully digital data devices. They were doing both paper and computer data gathering because they either didn't have enough memory to save all the data so they just took samples based on a timer, while gathering lots and lots of data on paper to be sure they wouldn't lose their data. We might have used something like that when we were doing EMP testing with nukes in Nevada, USA, because the paper-saved data wouldn't get 'nuked'.
2006 NEC San-ei Instruments, Ltd. was acquired by Nippon Avionics Co, Ltd (Avio). Then changed the trade name of NEC San-ei Instruments, Ltd. to NEC Avio Infrared Technologies Co., Ltd.
Check back next week and the dumpster will have the other parts of the nuclear reactor.
Typical analog/temperature multichannel logger/printer.
We used these in testing activities on cars to record voltages and temperatures on long test drives. Also for test monitoring.
The plot trace is a series of dot traces in multicolour lines. The units we used produced both data records as well as chart traces.
Depending on model thermocoupleall types selectable, or RTD, or alternative analog voltage input ranges.
I have actually seen this type of mechanical connection for the power button twice. It was used for a multi-position input selector switch on an old hifi stereo amplifier I took apart and it was also used in my old gould brand digital oscilloscope. In the oscilloscope it was unfortunately missing and due to me not being able to find something similar, I actually needed to design a push-rod and get it 3d printed in order to get a working switch on my oscilloscope. I have no idea what it would be called, but would be interested in that as well.
Found it, just had to search for san-ei + NEC, and up came this:
www.avio.co.jp/english/company/history.htm
The company was acquired by Nippon Avionics Co. Ltd. in 2006, and the reason the website vanished in 2008 is the company name was changed to NEC Avio Infrared Technologies Co., Ltd. They don't make this sort of thing any more, they make thermal cameras, various micro-joining tools, and radiation-hardened DC-to-DC converters.
Those power switch lines are very common in 00-s Pioneer power amps
the (A+ B- B) terminals are for the PT100 temperature sensor only and other types of sensors use only (A+ B-).
15:02 : yes, both Sony SCD-1 and SCD-777ES SA-CD players (1999) have a remote power switch on the back, right at the AC wiring entrance, and this switch is activated by a metal ribbon. See pages 14 and 15 : www.docs.sony.com/release/SCD1_TWP.pdf
This Kind of blue remot-switch seems to be quite popular in audio equipment (f.o.r. Denon or Marantz amplifiers)