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.
Note the connector on the end of the device. This is an OBD2 diagnostic connector. If your vehicle is a US model (elsewhere?) and model year 1997 or later, it has one within three feet of the driver’s seat, usually under the dashboard.
On this port are +12 volt power, supplied from the engine control module, and several data lines. Newer vehicles likely use a CAN bus that is essentially grand central — everything uses it for communication.
You should simply not mess with this port if you don’t know what you’re. Here are some good reasons why.
A) Possible ECM damage.
The DC power on this port is limited. Short it out and one of two things happen. If you’re lucky, a fuse in the fuse box blows. Your vehicle shuts down immediately and will not restart until it is changed.
If you are not lucky, a circuit trace or internal pico fuse inside the ECM pops. Same as above, but you CAN’T replace it. Your vehicle is BRICKED. It’s possible the fuse protects only the OBD2 PORT power, in which case no diagnostic tools will work on the port until it’s fixed. Engine fault codes can’t be retrieved or cleared, and it will not pass an emissions inspection.
Internal repair to the ECM will be needed which may or may not be possible.
ECM replacement may be an option on older vehicles, but on newer ones and most European ones, you may find you also have to replace other modules that are keyed to the ECM for security (and service resistance) reasons.
B) “who the fuck is really driving?”
Did you see where I said that *everything* depends on that CAN network on newer vehicles? I mean it.
So here’s what can happen if the device were to mess up the CAN communications.
First off, your vehicle will likely shut down immediately or act really weird for a moment before doing so.
Second, you may lose control and crash. Seriously.
On some vehicles, a lot of functions that really shouldn’t be on the network in my opinion are.
Things like control over power brake assist, power steering, throttle….
I should mention how much I love my car’s hydraulic pedal clutch, old school hydraulic power steering, vacuum brake assist*, and manual transmission about now.
Even more worrisome is the thought that the hotspot device may actually be capable of sending and receiving data on the bus. It has metal pins in all the right places, at least.
Recently it was proven that CAN bus access could be used to remotely cause loss of control on a Chrysler vehicle and run it off into a ditch.
Don’t use this shit. ZTE should be fucking ashamed for even making it. It would have been just as easy to make it plug into a lighter socket; many vehicles have extras, some of which have constant power.
* Actually there is an ABS pump, which may still be able to override brake pedal pressure, but nothing can disable the handbrake for the rear wheels… At least there’s that. WTF is with those electric parking brakes?!
Whenever dealing with old electronics, you will always run into some annoying tart who exclaims, “but look at wat its wurf on da eeeeebay!!” and waves an unsold buy it now listing in your face. I’ve written about this previously.
Here’s how to properly wurf.
Skip bathing for a few days, rub the contents of an ashtray all over yourself and breathe through your mouth.
Go to eBay and sign in. Don’t have an eBay account? WTF are you doing wurfing anyway? Repeat step one.
Search for the desired item.
For this example I’m using the Yaesu FT-101 which is a 30 year old HF radio, great for its time but now dated and a pain in the ass to maintain due to dwindling availability of PA tubes.
This is where your truly awful wurfers stop, upon seeing that high unsold buy it now price.
Scroll down. Set condition to used unless the item is brand new in original packaging. Otherwise I’m gonna have to stab you.
See that Show More option? That’s a magic button, pressing it will allow you to attain true wurf.
Tap sold items. This will check completed as well automatically.
You have wurfed. Tap done and view the results:
Yes, you can do the same thing from desktop eBay search, but most wurfing takes place on smartphones now.