EEVblog #618 - Mailbag - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: May 20, 2014, 02:30:29 pm
content: !Private video

author: TVman
author_rank: Frequent Contributor
timestamp: May 20, 2014, 03:27:26 pm
content: Oh Goody, Another man opening bags.

author: Neverther
author_rank: Regular Contributor
timestamp: May 20, 2014, 04:28:50 pm
content: Gen 1 tube is restricted?Dual gen 0 costs around 90$ here with helmet, HV supply and carry case with spare parts (PNV-57a, I bought one with broken supply from local store and fixed it).There is a load of gen 2+ and 3s on US ebay for hunting and other sports.Europe has old russian cyclops scopes (gen 1) and german Fero 51 surplus for sale.Also, an UK seller has gen 2 philips tubes and australia is not excluded from the list....

author: Zad
author_rank: Super Contributor
timestamp: May 20, 2014, 05:07:15 pm
content: Those oldschool UV-erasable PIC micros are great for educational tools, showing people what is inside a chip. Top tip: I don't have a fancy microscope, so I popped one on my flatbed scanner.

author: SeanB
author_rank: Super Contributor
timestamp: May 20, 2014, 06:57:23 pm
content: I was fixing those today. The transformer is 56VAC open circuit, but drops to 2V with the element. the timer is really simple, a half wave rectifier, a 4u7 capacitor and then a power resistor to drop 300V to drive the relay with 24V. The timing is set with a RC delay, with the 220k pot on the front providing the dalay along with a 47k resistor ( minimum time setting value) and a capacitor ( 10uF or 22uF depending on what they found), with a 6V8 zener diode driving the base of a NPN transistor that then drives the gate of a SCR ( CR02M on the originals, but I replace them with C106D when needed) that fires to short out the relay coil. LED is in series with the relay coil.Most common failures are the relay burning a contact, and shorting to the coil cooking pretty much everything. I also add a VDR to tame the spike across the contacts as they open. Mechanically the elements burn the ends, and then you need new end pieces. The switches also burn out, but are easy to replace. I have enough of these at work, and keep a lot of spare parts for them.

author: rsjsouza
author_rank: Super Contributor
timestamp: May 21, 2014, 05:15:59 pm
content: Great video. The TMS320 simply refers to all of TI's DSPs and the TMS320C5x development kit you have was very popular in its day. TI had published an entire set of assembly source files for a v.34 modem (here.The messaging gadget seems quite clunky nowadays but, in technological terms, 2005 is "a century ago". The wireless world back then was very fragmented in solutions and the path to the smartphones was not yet clear for the consumer market (mostly Treos and Blackberrys for the corporate crowd...) - not to mention the charges for GSM/GPRS wireless data were astronomical at theoretically 114kbps, but far from it in practice.That perhaps explains why a portable device with Wi-Fi at astounding 11Mbps (and free of charges) was an interesting idea... In the same year Palm released their Lifedrive with Wi-fi only (I still have mine), and all smartphones supported only SMS and e-mail...

author: mozzwald
author_rank: Newbie
timestamp: May 22, 2014, 04:14:15 pm
content: The Zipit Z2 is an older device, but it's quite versatile since it's been hacked and can run a full Linux distro. There's still a good community around the Zipit which I am a part of. Here's a little info about it:Made by Aeronix / Zipit WirelessPXA270 CPU 312mHz, can be overclocked to 520mHzMarvell 802.11b/g Wifi1230mAh LI batteryWM8750BG Wolfson Audio chip8MB NOR FlashRear port is a Hirose connector with USB, Audio, GPIO, Pwr, i2c, Pinout:http://bealecorner.org/best/measure/z2/z2-connector-pinout-2011.txtMini SD Slot on front (can be used with micro sd and adapter)Test points for jtag and uartLinux distros available: OpenWRT, IZ2JFFS (based on the stock/builtin linux), Arch, DebianThere's a bunch of info on my sitehttp://mozzwald.comand I have a page of links to other info athttps://mozzwald.com/node/171. Hop on irc.freenode.net channel #zipit if you have questions.