Danish Vintage LRC Meter Reveals Inside

April 14, 2024 by Al Williams 7 Comments

Modern test equipment is great, but there’s something about a big meter with a swinging needle and a mirror for parallax correction that makes a device look like real gear. [Thomas] shows us a Danish LCR meter (or, as it says on the front, an RLC meter). The device passes AC through the component and uses that to determine the value based on the setting of a range switch. It looks to be in great shape and passed some quick tests. Have a look at it in the video below.

An outward inspection shows few surprises, although there is an odd set of terminals on the back labeled DC bias. This allows you to provide a DC voltage in case you have a capacitor that behaves differently when the capacitor has a DC voltage across it. Continue reading “Danish Vintage LRC Meter Reveals Inside” →

Vintage Particle Counter Is A Treasure Trove Of Classic Parts

April 13, 2024 by Dan Maloney 1 Comment

If you need a demonstration of just how far technology has come in the last 40 years, just take a look at this teardown of a 1987 laser particle counter.

Granted, the laser-powered instrument that [Les Wright] scored off of eBay wasn’t exactly aimed at consumers. Rather, this was more likely an instrument installed in cleanrooms to make sure the particulate counts didn’t come out of range. As such, it was built like a battleship in a huge case stuffed with card after card of electronics, along with the attendant pumps and filters needed to draw in samples. But still, the fact that we can put essentially the same functionality into a device that easily fits in the palm of your hand is pretty striking.

[Les] clearly bought this instrument to harvest parts from it, and there’s a ton of other goodness inside, including multiple copies of pretty much every chip from the Z80 family. The analog section has some beautiful Teledyne TP1321 op-amps in TO-99 cans. Everything is in immaculate condition, and obsolete or not, this is an enviable haul of vintage parts, especially the helium-neon laser at its heart, which still works. [Les] promises an in-depth look at that in a follow-up video, but for now, he treats us to a little tour of the optics used to measure particulates by the amount of laser light that’s scattered.

All things considered, [Les] really made out well on this find — much better than his last purchase.

Continue reading “Vintage Particle Counter Is A Treasure Trove Of Classic Parts” →

Teardown Of Two Russian Missile Sensors

January 5, 2024 by Maya Posch 22 Comments

Recently [Michel] received two packages from Ukraine containing some salvaged Russian electronics that once belonged to (presumably) a 9K38 Igla, Vympel R-27 or similar infrared homing missile, as well as a Fiber Optic Gyroscope (FOG) from an unknown missile, though possibly from the Tornado family of MRLSes. The latter uses the Sagnac effect to detect the phase shift between two laser beams being injected into the same fiber when the fiber, and thus the device, are rotating. The advantage of such a gyroscope is that it is effectively solid-state, requiring only some optical components, amplifier stage and as shown here an Altera Cyclone II FPGA to integrate the results.

The 16-channel linear infrared array sensor is more basic, with a matching amplification channel for each optical receiver element, which are fed into a multiplexer IC in a rather remarkable looking ceramic-gold packaged DIP format, with what looks like a 2004 date code (‘0424’). Although both are rather damaged, [Michel] figures that he might be able to restore the FOG to working condition, assuming no crucial and irreplaceable parts are missing. As useful as FOGs are in missiles, they also have countless uses outside of military applications.

Continue reading “Teardown Of Two Russian Missile Sensors” →

The Height Of 1960s Dental Electronic Technology

November 9, 2023 by Jenny List 9 Comments

If you’ve ever been to the dental surgery and found yourself requiring some gum surgery, the chances are you’ll have found your dentist wielding an electronic probe to cauterise the flesh. It’s evidently some form of RF device because you are usually required to hold one of the electrodes while it’s being used, but annoyingly, for an engineer, it’s hardly the time or place to ask how it works. For the curious, then, [Keri Szafir] has the box of tricks behind the probe and is subjecting it to a teardown.

The box on her bench isn’t the one you’ll find in your dentist’s toolkit today, but its distant ancestor from the 1960s that integrates multiple functions into a single box. It’s a very period enclosure with typically 1960s-style vacuum tubes and point-to-point wiring. There’s an HF oscillator using a pair of EL81 power pentodes for that electrode you always wished you could ask your dentist about, and unexpectedly, a thyratron, a type of gas-filled switching tube not dissimilar to a thyristor, in a separate circuit for dental pulp testing. We’re not dental experts here at Hackaday, but [Keri] has done the research and explains the device in the video below the break. At one point, she observes that it’s quite a scary machine to be connected to a living person, and we can concur with that.

Her bench has provided a few projects here in the past, including one of her amplifiers. While it might be fun to tear down a more modern version, you are better off asking for old dental burrs.

Continue reading “The Height Of 1960s Dental Electronic Technology” →

Just How Dodgy Are Cheap USB Chargers Anyway?

November 3, 2023 by Dan Maloney 49 Comments

Aside from apparently having both the ability to reproduce on their own and simultaneously never being around when you need one, USB chargers seem innocuous enough. The specs are simple: convert mains voltage to 5 volts, and don’t kill anyone while doing it. Both specs are typically met by most designs, but judging by [DiodeGoneWild]’s latest USB charger teardown, the latter only just barely, and with a whole lot of luck.

The sad state of plug-in USB power supplies is one of [DiodeGoneWild]’s pet gripes, and deservedly so. Most USB chargers cram a lot of electronics into a mighty small volume, and are built to a price point, meaning that something has to give in the design. In the case of the two units he tears apart in the video below, it’s pretty clear where the compromises are. Neither unit met the specs on the label in terms of current supplied and voltage regulation, even the apparently more capable quick charger, which is the first to go under the knife. The PCB within holds some alarming surprises, like the minimal physical isolation between the mains part of the circuit and the low-voltage section, but the real treat is the Schottky diode that gets up to 170°C under full load. Safety tip: when you smell plastic burning, throw the thing out.

The second charger didn’t fare any better; although it didn’t overheat, that’s mainly because it shut itself off before it could deliver a fraction of its rated 1 amp output. The PCB construction was shoddy in the extreme, with a squiggly trace standing in for a proper fuse and a fraction of a millimeter separation between primary and secondary traces. The flyback transformer was a treat, too; who doesn’t want to rely on a whisper-thin layer of cheap lacquer to keep mains voltage out of your phone?

All in all, these designs are horrible, and we have to thank [DiodeGoneWild] for the nightmares we’ll have whenever we plug into one of these things from now on. On the other hand, this was a great introduction to switch-mode power supply designs, and what not to do with our own builds. Continue reading “Just How Dodgy Are Cheap USB Chargers Anyway?” →

Vector Network Analyzer Demo And Teardown

October 18, 2023 by Donald Papp 10 Comments

[Kerry Wong], ever interested in trying out and tearing down electrical devices, demonstrates and examines the SV 6301a Handheld Vector Network Analyzer. He puts the machine through its paces, noting that the 7 inch touchscreen is a pretty nice feature for those whose eyesight isn’t quite what it used to be.

The internals are similar to the nanoVNA-F V3, but not identical.

What’s a Vector Network Analyzer (VNA)? It’s not for testing Ethernet or WiFi. It’s aimed at a more classical type of “network”. The VNA tests and evaluates characteristics of electrical networks, especially as related to RF and microwave.

It provides detailed information about properties across a specified frequency range, making it an indispensable tool for advanced work. Tektronix has a resource page that goes into detail about exactly what kinds of things a VNA is good for.

[Kerry] shows off a few different features and sample tests before pulling the unit apart. In the end, he’s satisfied with the features and performance of the device, especially the large screen and sensible user interface.

After all, not every piece of test equipment does a great job at fulfilling its primary function, like the cheap oscilloscope that was a perhaps a little too cheap.

Continue reading “Vector Network Analyzer Demo And Teardown” →

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…

Continue reading “Turning Soviet Electronics Into A Nixie Tube Clock” →