Industrial Surge Protector Teardown

September 10, 2023 by Al Williams 12 Comments

Surge protectors are a common item in the modern household, but the Meanwell unit that [Big Clive] tears apart was clearly intended for commercial use. In fact, he mentions it was made for outdoor signage. Removing the rear panel didn’t help much — the entire unit was potted in resin — but that didn’t stop [Clive]. Removing the resin revealed only a few components surrounded by a sand-like substance.

There’s no circuit board inside. Components are just wired together before potting. The significant player inside is a metal oxide varistor with a thermal fuse. [Clive] draws out a schematic, which is deceptively simple. The two LEDs are an older style of green LED, and he explains why the choice of LED is important in this application. In typical operation, the LEDs light. If a fuse blows, at least one of the LEDs will extinguish.

Not all useful circuits have to be complicated. This is an excellent example of how a simple but well-constructed design can succeed commercially.

Not all surge protectors are built this well. If you need a refresher on how varistors work, we can help with that.

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Rare Arcade Game Teardown And Mods

September 9, 2023 by Al Williams 7 Comments

[Video Game Esoterica] loves a 1990s video game called Operation Tiger. Apparently, there are only a few of these known to exist in 2023, and he managed to find one of them. Well, it is really just a module so he has to figure out how to give it enough input and output to be actually playable. You can see several videos of his work with the Taito game below.

The board has a lot of ICs and a Power PC to handle the 3D graphics. The graphics seem clunky today, but they were impressive for the time. According to the video, the CPU board was only used for this game. The ROM that holds the software is separate with a mix of mask-programmed memory and EPROMs.

The machine is meant to live in an arcade box. So wiring things like coin selectors, video, speakers, and controllers is a non-trivial exercise. The wiring paid off, though, as the board started up but with no buttons, it wasn’t able to start in the first video. The controls go through a 60-pin connector and he tackles that project in part two.

The next step is to actually update the game software, which is hard but possible. Of course, you can run many of these old games with MAME or, if you prefer, use it to score that primo engineering workstation you used to covet.

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An Unexpected Appearance Of An Iconic Motorola Chip

August 31, 2023 by Maya Posch 24 Comments

Big Clive's reverse-engineered schematic of the USB charger containing the MC34063 IC. — Big Clive’s reverse-engineered schematic of the USB charger containing the MC34063 IC.

Generally when you crack open a cheap car-to-USB charger unit that came with some widget, you do not expect to find anything amazing inside. That’s why it was such a surprise to [Big Clive] when said car USB charger revealed a blast from the past in the form of an MC34063. This is a switching regulator that supports buck, boost and inverting topologies, but perhaps it most notable feature is that it was first produced by Motorola in the early 1980s.

This particular IC is marked as having been produced by ON Semiconductor which means that it’s technically still manufactured by Motorola – with ON Semiconductor being the Phoenix division that was spun off in 1999 – but it’s somewhat remarkable that this particular chip isn’t only produced by ON Semi today, but also by Texas Instruments. Much like the venerable NE555 timer IC and Intel’s 8051 MCU architecture, it would seem that certain chips and designs are simply made to become commodities in the future.

This appears to be the case for the MC34063 as well, which may lack some niceties of more modern ICs, such as built-in thermal protection, and it switches at only up to 100 kHz, but it can be bought for peanuts, has a wide input voltage range of 3 to 40 V, can switch up to 1.5 A and supports multiple common topologies. Often a 100 kHz switching regulator is all you need, in which case it’s handy to have a stack of such commodity chips lying around, plus the MC34063 comes in PDIP packaging as well, which is a boon for prototyping.

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Retro Gadgets: The 1974 Breadboard Project

August 29, 2023 by Al Williams 36 Comments

It is hard to imagine experimenting with electronics without the ubiquitous solderless breadboard. We are sure you have a few within arm’s reach. The little plastic wonders make it easy to throw together a circuit, try it, and then tear it down again. But, surprisingly, breadboards of that type haven’t always been around, and — for a while — they were also an expensive item. Maybe that’s what motivated [R. G. Cooper] to build Slip-n-Clip — his system for quickly building circuits that he published in a 1974 edition of the magazine Elementary Electronics.

The system isn’t really what you would think of as a breadboard today, but it was effective and certainly cheap to build. The biggest problem? It wasn’t something you’d use with DIP ICs. But in the early 1970s, you might not be building very much with ICs, and the ones you used might be in oddball transistor-like packages. Things were strange in the 70s!

A Brief History of Breadboards

In the very old days, people built radios and such on wooden substrates that were actually bread-cutting boards. That’s where the name came from. It was common to draw a diagram with the physical layout you had in mind, glue it to the board, and use it as a guide for building and troubleshooting. Wood was easy to drill and cut. A nail or a thumbtack would make dandy terminals. Probably the last time we saw that done was about a dozen years ago in Make Magazine. Even then, it was only a novelty — few people still build circuits like this, but you can see how [Colin] did it in the video below.

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Turning Soviet Electronics Into A Nixie Tube Clock

August 27, 2023 by Donald Papp 17 Comments

Sometimes you find something that looks really cool but doesn’t work, but that’s an opportunity to give it a new life. That was the case when [Davis DeWitt] got his hands on a weird Soviet-era box with four original Nixie tubes inside. He tears the unit down, shows off the engineering that went into it and explains what it took to give the unit a new life as a clock.

Each digit is housed inside a pluggable unit. If a digit failed, a technician could simply swap it out.

A lot can happen over decades of neglect. That was clear when [Davis] discovered every single bolt had seized in place and had to be carefully drilled out. But Nixie tubes don’t really go bad, so he was hopeful that the process would pay off.

The unit is a modular display of some kind, clearly meant to plug into a larger assembly. Inside the unit, each digit is housed in its own modular plug with a single Nixie tube at the front, a small neon bulb for a decimal point, and a bunch of internal electronics. Bringing up the rear is a card edge connector.

Continues after the break…

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A Guide To Field Stripping Your Voyager Tricorder

August 14, 2023 by Tom Nardi 8 Comments

For the last few years, [Mangy_Dog] has been working on what is easily the most technically and aesthetically impressive Star Trek tricorder prop the world has ever seen. With each new version of the hardware we’ve gotten the occasional peek under the hood or source code walk-through, but these limited presentations have made it somewhat difficult to really appreciate the scale of this undertaking.

But now thanks to this epic hour-long tour of the hardware and software that makes up version 2.5 of his Voyager tricorder, we can finally see just how incredible the engineering that’s gone into this project really is. Every detail has been meticulously considered to deliver a final product that’s not only as visually accurate as possible, but reliable enough to actually carry around. Continue reading “A Guide To Field Stripping Your Voyager Tricorder” →

Portable 1990s POS Will Strain Your Back

August 13, 2023 by Chris Lott 4 Comments

[JR] over at [Tech Throwback] got ahold of an unusual piece of gear recently — a portable Point of Sale (POS) credit card machine from the late 1990s (video, embedded below the break ). Today these machines can be just a small accessory that works in conjunction with your smart phone, but only the most dedicated merchants would lug this behemoth around. The unit is basically a Motorola bag phone, a credit card scanner, a receipt printer, a lead-acid battery, and a couple of PCBs crammed into a custom carrying case

Despite having a lot of documentation, [JR] struggles to find any information on this U.S. Wireless POS-50. He finds that the credit card scanner is an Omron CAT-95 authorization terminal, and the Motorola SCN-2397B phone appears to come from the Soft-PAK series.

He is able to power it up, but can’t do much with is because he is missing the authorization password. But regardless, with the demise of the Advanced Mobile Phone System for over a decade, this 850 MHz band analog phone can’t connect to the network anymore.

If you happen to know anything about this old POS, or used a similar luggable system for accepting credit cards in the 1990s, let us know in the comments below.

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