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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/

  • Heh, the Warp-13A was what finally drove me away from PIC and toward ARM/AVR. I bought it because Microchip refused to document their protocol, but it offered a documented protocol, which meant I could use it with open source software. Then new PIC chips came out, and (presumably because it ran out of memory for two protocols), to get support for them, it lost the ability to use the documented protocol. At that point, I gave away all my PIC chips and gear and transitioned to AVR.

  • What is a “shirt-button rectifier”?

  • I must differ with the notion of “selling to the highest bidder”: this information will be sold to EVERYONE who offers money for it, not just the “highest bidder”. As for protecting communication from devices incapable of effective SSL, it is easy enough to dedicate a computer on your local network to proxy SSL connections out over the internet.

  • It would have been handy to route CMout to a pin as well. I think there’s an error in the schematic, which says when mounting in a metal chassis to connect J3 to the chassis with a heavy wire. I think that should read J9.

  • Time: 04:26:32 Combo: 25/50/25

  • Coming from a pinball background, I got used to the Molex “KK” series 0.156" board to wire connectors. They’re cheap, versatile, reliable, durable, and have plenty of options. For my fancy stuff, I used the gold plated pins and gold plated “trifurcon” contacts. For everything else, the ordinary tin ones work fine. For smaller stuff, the ordinary 0.1" square header pins work fine, and there are plenty of options for plugging onto them. Both of these sell the receptacle housings and contacts separately, so you assemble the contacts onto your wires and then put the contacts into the housings, where they lock into place. There are also IDC options available. I was pleased to discover that for board mounted antennæ, the u.FL connectors have become sort of standard. I use ‘em for WiFi, Bluetooth, GPS, cellular, etc. It’s easy to find inexpensive antennæ with those connectors already on them, and there are adapter cables to other common connectors (BNC, SMA, R-SMA, etc.).

  • I’m not Pete, but I’ll point out that I buy Molex 0008580122 contact pins for that situation. They’re gold plated, and Digikey offers them as their part number WM2304-ND and have 5800 in stock for immediate shipment. There’s no minimum quantity either: you can buy a single pin for 54 cents, or 50 for $20.28.

  • Mine’s another tube circuit: a musical Jacob’s ladder. The output of a big beam power tube drives the primary of an oil burner ignition transformer lashed to V-shaped wires. Plug in a guitar, hit a string, and hear it an a zappy arc. All point-to-point wiring with terminal strips, connectors, and tube sockets. view of circuitry

  • 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).