Listing contents with tag Curiosities:
And now something totally different, related more to electricity than electronics. These electricity meters were commonly installed since 1990s in many households and were used until early 2010s when they were replaced with digital meters. The principle of operation is quite simple: There are two coils: One energizes because there is mains voltage flowing through it all time. The second coil is put in series with energy receivers, so it energizes when current flows through it. If both are energized, it means that there is both voltage and current, and voltage times current equals power. Action of both coils induces eddy currents in a flat aluminum disc, it rotates and spins the counters, like in a peculiar low-power induction motor with 90-degree phase difference made by two coils.
The curent constantly present in voltage coil draws some energy, but it is not integrated to total power consumption.
A neutral wire is connected through a pass-through, while live is passed through coil. Additionally...
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Mera V640 is a multimeter made by Polish Meratronik plant in 1970s. It is an analog meter, able to measure voltages (1.5mV - 1500V), currents (0.15uA - 1.5A) and resistance. With specialized probes it was possible to measure high frequencies and even temperature.
In 1970s Poland started to make international deals, usually with licenses. Some licenses were bought, like from British ICL for their computer designs, German (western) Grundig (tape players), or Japanese Busicom for calculators, but Poland also manufactured their equipment for export. In 1972 the Masteranger 639 multimeter has been made for Conway, a Canadian electronics company, and manufactured purely for export. The design was successful enough that it was also manufactured for British Marconi company as TF 2650. Year later it was also sold in Poland, under V640 name, after some changes in range switch and adding temperature probe.
These times, export and import with eastern block country was very different than typical transaction,...
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Recently I acquired a few power supply units for PCs and I decided to share some knowledge about their quality. Because these units were defective I had to open them, fix if possible, and re-solder wires as they were from some e-junk wjere copper is valuable.
Testing was simple: Load the power supply unit with an old, damaged IDE hard disk, turn it on, check voltages (they should not be well OK, as one old hard disk is not enough to keep regulated line), then load the unit on 5V line with 12V/21W light bulb and check regulation then. Most passed these tests after capacitor repairs.
Let's see the first example: The Tagan TG380-U01. Tagan is known as manufacturer of a good, high-end power supply units, and it looks like they made them really well. The unit is packed with technology, they put large heatsinks and thermal regulator on a separate, small board. Because packing is tight, two fans are pumping air through the unit.
Here is an example how the good power supply unit...
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Some time ago I was looking for an used adjustable power supply unit. Finally I had a possibility to purchase a 300W adjustable (0.1-30V, 10A max) power supply unit for a relatively lower price. The only thing about it was that it was a unit from early 1970s, transformer-based, 25kg of hardware. I finally got it, brought home and decided to restore it.
It is a ZTR-1/71 power suply unit made by Inco in Poland. In 70s and 80s, Inco (Full name: Zaklad Produkcyjny Aparatury Elektronicznej INCO) was known manufacturer of measurement devices, lab equipment and all "special" production e.g. for military, intelligence or security offices (also devices for communication, location of radio stations or radar applications), so I expected quite interesting things inside. It is still possible to get their old catalog on Silesian...
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