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Madbodger

Member Since: January 12, 2008

Country: United States

Profile

Programming Languages

C, Java, XSLT, assembler

Expertise

Vacuum tubes, neon, microcontrollers, electronics

Interests

Neon, reading, building, making

Websites

http://www.vitriol.com/ http://bodger.dreamwidth.org/

  • I’m guessing the antenna comments should go with the RFID reader description, not the tags (I would be surprised but oddly pleased to find a u.FL connector on an RFID tag).

  • Off the top of my head, here are a few advantages to bench supplies over wall warts. They’re better protected, so if you overload them, inadvertently connect them to some other voltage, etc., they’ll usually survive intact: wall warts can be destroyed or blow internal fuses that are annoying to replace. They’re well regulated, whereas wall warts can provide anything from DC to DC that varies with the load (I’ve seen double and triple the rated voltage at light load), half-wave rectified DC (basically pure ripple), or even AC. The grounding on bench power supplies is generally well-defined and explicit: the best ones are floating, so you can tie either the positive or negative output to ground, and “stack” supplies to add voltages or provide intermediate voltages. Similarly, many offer “tracking”, so you can adjust multiple outputs in synchrony (useful if you happen to need equal positive and negative voltages). Here’s a picture of a project that’s getting a lot of use out of a triple-output power supply for circuitry that runs on several different voltages (the little boards hanging from wires in mid-air are additional regulators for yet more voltages).

  • Sources of fog are nice for cosplay, too. Some cosplayers would like to produce huge clouds of billowing fog from a tiny device, and the popularity of vaping and ingenuity of the Chinese have made the hardware much more varied, affordable, and accessible. I have no interest in vaping, but much interest in miniature fog machines and power engineering. At the end of the article, where it refers to DC-DC boost supplies, I immediately thought “point of load buck (not boost) supplies would be the way to go for this sort of low voltage, high current duty.”

  • Have you seen the “flip pin” headers that work better with breadboards than the ordinary square pin ones?

  • In this case, all the mode lamps were run from the same AC supply as the backlights, just switched by another deck on the mode switch. The only ones that are switched electronically are a pair of bulbs that show stereo reception. They seem to be run in series from a 13VDC supply via a resistor, and are switched by an ordinary BJT. I’m guessing Byron replaced them too.

  • All my life, I’ve been at loggerheads with time. I love seeing someone smart and creative attacking my issues with time head-on!

  • I’ve been at this for a very long time, and it’s still fun for me. I still burn components from time to time, and I’m still surprised on a regular basis. I enjoy all of it, and try to learn from each mistake and surprise.

  • I had a heating pad once that I was using as a warmer for a sick pet. The automatic 2-hour shutoff wasn’t a feature I wanted, so I opened the controller, and found well-marked pads for choosing 2 or 10 hour shutoff and to disable it entirely. I documented it on my website, and I’ve actually gotten a couple of emails thanking me for doing so, as other people doing similar things could use the information.

  • Yeah, a half watt is plenty at a reasonable current, but many manufacturers run the neon bulb at way too much current to get more brightness. In those circumstances, the resistor usually burns before the neon bulb dies.

  • “Delete” was also known as “rub out”. It was useful when there was a typo on punched paper tape. Since it was all holes punched (all 1s in binary), punching it on top of any character would replace it with “delete”. It was easy enough to make paper tape readers just ignore any such instances, avoiding the need to repunch a whole tape if one character was mistyped.