Recent content by juming

Aha! I forgot about the Smithsonian! That's definitely going on the list. And I've no idea where Lichtenburg is... I'm in Johannesburg Thanks for the book suggestion too - I'm buying it now! Cheers.

Hi, I'm looking for suggestions for holiday destinations with a physics flavour. Currently my list includes CERN, FermiLab & somewhere to view the Aurora Borealis... but please offer any suggestions you've been to, heard of, and/or are on your 'bucket list'? I've scoured the web & these...

haha, good question. and somewhere along the lines, a dB is also 20log(something)

berkeman ... Quick Field? i'm an ee student... that's what we used in our field theory and electromagnetic theory courses. www.quickfield.com

... and as an engineering student and having no idea about the market... i don't know what to do, so i thought i'd ask you guys - as i don't have much time! my project has been to create a bluetooth <> zigbee gateway... but in the form of a home automation scheme. at the moment i have it all...

... well said!

danger, yeh... its not specifically tuned... that's just an american website :)

Danger: http://en.wikipedia.org/wiki/X10_(industry_standard ) http://www.smarthomeusa.com/info/x10theory/x10theory/#theory NoTime: I'm basically trying to build an electronic light switch of my own, but I need a DC power source in the light switch, so I'm not after X10 specifically, just the...

Hey, Older homes use a loop-in arrangement where the two wires coming down to a light switch are both live, and the neutral's nowhere near. The X10 "plug n play" switches leak a small current through the light and draw their current from there... I was just wondering, how exactly do they do...

Google says Canuk = Central Association for Nigerians in the UK ... ? :-p

What better time to start than now! :) that's why I was looking for the easiest & smallest solution to quickly bring the AC mains to a 5V DC that I know! :) how about this... is this feasible: If i use a rechargable battery & then somehow inductively couple power from the mains line when it...

haha! yes... laptop thing is a bit too bulky... i'm looking for this to include in a design that will hopefully fit in that small gap in the concrete behind a lightswitch... wait... if you're an american with those woody housey things, let me explain... real houses are built of bricks... its...

Hi there, I'd like to switch 220-250v AC (50/60Hz) to 5 or 3.3v DC as easily and in the physically smallest way possible. Can someone offer advice on this? Do there exist IC's that will just do this for me? I have experience with LSR's but a transformer is too bulky for my needs. Thanks!

RE: berkeman the RFID tag I'm using is the TK5530 by Atmel (they bought out Temic) and the reader IC is the U2270B. The 125kHz low frequency RFID system is usually used for passive tags & small reading distances (8 to 30cm) from the U2270B (reader) datasheet: Features • Carrier Frequency fosc...

after much research & calculation, it seems to me that planar inductors can only be used for inductances in the range of nH to uH, and not mH. For a 1.35 or 1.5mH inductor i would have to use a ferrite core? or can i use an air-core inductor? (for a frequency of 125kHz)