Preparing for renovations of the engineering office here at work. I just got my bench and organized it aaaaand it’s gone– gone to get bigger and better. Oh well. Here, have some random nonsense.
I want to make a little collage of any ICs I find that were made the same week I was born. Some of the Z80 peripheral chips below are close but no cigar. They’re the right quarter, but a few weeks off.
“All mentions of the word ‘chameleon’ should be preceded by five commas. In all other instances, they come and go.” – @FakeAPStylebook
Now this is why you don’t let me play with your model trains. They wind up with gnaw marks.
This one needed to be put on a track where it moves forward when triggered by a sensor, then moves back.
I had two options here:
A) interface to the locomotive’s onboard controls and use extra sensors and aaaaaaaaaaaaaaaa—–
B) simple DC control using relays and diodes
Oh my glob it’s busy in there
The motor has a tachometer sensor – I guess you can really tell it “okay, go scale speed of 79″…
Yaaaaccckkkk. Wire nutted leads go to chassis ground and third rail.
One of the drive motors and the smoke machine
Bro, do you even vape? (I opened it to see what the motor was all about. It’s a fan to propel the smoke upwards.)
One of my favorite Arduino clones, and the relay board. This controls two identical train setups. One relay on each side starts and stops the train, the other sets the direction.
Leftover parts. I removed the extra bits because it’s remarkably hard to get the top back onto the locomotive with all that in there– it kind of barely fit!! I’m keeping the harnesses as intact as possible in case anyone ever wants to reverse the modification.
The way it works: I have each track installed with a gap in its third rail.
At each end of the line is an isolation block to stop the train. Its travel direction is determined by the DC power polarity. That being the case, I used a diode in line with each end section to essentially make it a one way street leading back from where the train just came in. The train will move until it loses power due to the diode being reverse biased, but flipping the polarity will give it power again to move the other way.
Originally I thought I was going to need more relays and other jank until I realized it just didn’t have to be that hard. 🙂
As for the title, no, I’m not just referencing the Principia Discordia again, it’s referring to the Multiple Unit cables used to control a locomotive from the cab of another leading or trailing locomotive, or from a cab car on the opposite end of a passenger train. Prepare to laugh about the fact that the Woodward Governor is basically a mechanical digital to analog converter with pseudo BCD inputs feeding a hydro-mechanical comparator to set the engine fuel rack for a commanded rpm… Cute, right?
These relays contain a diode in series with the 12 volt DC coil.
No, not in parallel (used to stop back emf from shooting out transistors driving the relay coil) — series.
Connect the coil up backwards and nothing happens.
I have never seen this configuration before and no, of course I didn’t notice it *after* wiring four of them backwards then wondering why all four appeared bad.
If the issue had been parallel diodes, my current limited bench supply would have just gone into constant current foldback at like .6 volt and 200mA and thus alerted me to the problem… But it couldn’t be that easy now could it?
Due to the fact that this thing is colossal shit and I feel bad for even recommending its purchase, I am going to classify this as 100% PURE SHITPOST. I feel genuinely bad. The thing does actually work…. SOMEHOW… though the VU meters don’t. Only the first four lights will illuminate. Gee I wonder why? (The fake STMicro chips are the drivers.)
I’d been warned many times that Behringer products are of quite subpar quality, and this had always been my impression as well, but I’d never actually opened one up and seen the horror within. This is FRESH FROM THE FACTORY and it’s got blobs of corroded crap inside. ARGH!! At least… whatever was splodged on the board and initiated said corrosion rinsed away with CRC QD Electronics Cleaner…
As an added bonus, here’s a Funai TV on fire. It’s supposed to be flame retardant, but the only thing that finally stopped it was a blast from the garden hose. Yeah I’m sure it met the specifications it got UL listed under….. if it ever actually was and didn’t just have a UL logo stamped on it in utter fraud. 😉
This ginormous inverted pyramid of piffle is supposed to use a multi track recording of a jazz performance to interactively demonstrate to a visitor how each instrument contributes to the piece.
Unfortunately it’s implemented very badly. For one thing, if the signage is to be believed, it doesn’t work right at all. When you press a button, the selected instrument is bumped up a couple dB, but it’s by no means noticeably isolated.
Second, check this baby out. This is the speaker system seen at the top of the first picture. Not shown: in the table base is a powered subwoofer that’s not shown on the prints, I have no clue where its audio source comes from, and it was once guilty of having blown out violently, filling the gallery with capaci-funk.
That’s twelve Klipsch 70v driven speakers, each on its own circuit back to the central a/v system, where it has twelve different amplifier channels.
So today the time came to simplify… when two of the 8 channel amplifiers flipped out. The prints at left are next to useless due to countless undocumented emergency repairs over the years.
It’s not looking so great in the rack right now; the cabling will need to be cleaned up. For now it’s kinda one-year-temporary until many of the exhibits using the current system will be decommissioned.
What a mess… At least Jazz Jam was using a TON of still usable amp channels, and it sounds perfectly fine with the inputs and outputs merged.
I made an awful little passive mixer out of 1k resistors and perfboard that shall never be spoken of again. Okay, as my boss says, “Good Enough For Museum Work”. Yaaaaaaaaaggghhhhh
There’s a bright side to this– when those Crown amps die, Crown fixes them. It’s $402 maximum to get the amp back to us fully happy and operational again. A new one runs about $3600, so…. that’s a damn good repair cost.
I’ve been equally happy with the support and service from Crown’s broadcast/rf division. Always a nice company to work with.
Once upon a time, in a computing industry far far away, there were many, many manufacturers of hard disks and other storage devices. Each remained competitive by advancing technologies used in their work, challenging each other to let us store away more and more of our precious bits and bytes while preserving reliability and overall product quality.
(Click below for Castle Thunder, then continue.)
Then, the kingdom was invaded by an evil horde of businessmen hellbent on consolidating every business, putting as many people as they could out of jobs, offshoring, and cheapening everything they could get their hands on. Eventually there were only three manufacturers left, all completely offshored for cheap labor. Innovation into increasing storage densities, reliability, access times, and data transfer rates stopped entirely as there was no longer any need to remain competitive whatsoever – customers simply had no significantly better options. Meanwhile, product quality slipped so badly that the industry began to cut warranties to shift the burden of replacing dead drives entirely to the consumer, occasionally deciding to lengthen them only to cut them short again weeks later. Some vendors even locked away the warranty return process behind a special software utility that issues an RMA code, but only … if it felt like it.
It’s nice to see this is only a fairytale.
(Quite appropriate musical piece by Bob Orilee)
But this is the real world, so it’s nice to see that we don’t have to worry about things like the head stack on a hard drive being connected to the controller board by a dodgy little connector that touches a set of tin plated circuit board pads that corrode away just from things such as plastic fumes. Out here in the real world, the vendors at least give us a couple microns of gold protecting the connectors, right?
The good news…. I have successfully saved a couple of drives by removing the circuit boards and cleaning those pads. The bad news…. on the drive I photographed here, it seems like the firmware may have gotten trashed. Cleaning the pads restored proper servo operation and keeps it from just giving up and spinning down, but it just ain’t workin’. The piss yellow corrosion comes off with a pencil eraser. Drive pictured here is a Western Digital, but I’ve run into the same issues on a Seagate. Interestingly, I’ve never seen the same problems on a Hitachi GST drive. While Hitachi GST is owned by Western Digital, they haven’t had their engineering division cut off yet.
Back in the day I remember when Quantum was bought out by Maxtor… there was a hilarious transition period where you could buy a Quantum Fireball drive with a Maxtor sticker and firmware ID string in it, or a Maxtor DiamondMax drive (still bearing many engineering themes from Miniscribe such as the UPLEVEL numbers and all that) with a Quantum sticker on the lid. Alas, now, there’s no need for those pesky engineering teams, because there’s nobody to compete with. It has truly come full circle— and the circle I refer to is the circular path traced by a flushed turd as it approaches the drain.