Lie Detector Electronic Kit and Circuit Explanation
We’ve had a few emails and posts about folks who wanted to build their own lie detector, here’s one (and how it works) – “The circuit diagram of the Lie Detector is shown above. It consists of three transistors (TR1 to TR3), a capacitor (C1), two lights or LEDs (L1 & L2), five resistors (R1 to R5), and a variable resistor (VR1). Suitable transistors to use are BC547, BC548 or BC549, or any other small NPN transistor. The Lie Detector circuit works based on the fact that a person’s skin resistance changes when they sweat (sweating because they’re lying). Dry skin has a resistance of about 1 million ohms, whereas the resistance of moist skin is reduced by a factor of ten or more.” Link.
Not a bad deal for $49. “MIDISpeak Module – Version 2, The Talking Toy MIDI RetrofitAdds a standard MIDI IN port to your Speak & Spell, Speak & Read, or Speak & Math. Non-English versions also supported. Trigger thousands of sounds–words, word fragments, garbled speech, percussion and bizarre sound effects.” 
William on GoRobotics writes “The popular educational and hobbiest company, Parallax is finally 
In MAKE 04 we featured some great kit gift ideas in the magazine, “Kits for the Holidays”. But we didn’t have room for all the kits we found, so here’s another round for elves with makers on their list. MAKE subscribers can log in and view the full article 
“…Skype has struck a partnership with consumer electronics chain RadioShack. Skype Starter Kit More than 3,000 RadioShack locations nationwide on Monday will begin offering the Skype Starter Kit, which includes the software that enables a customer to use Skype’s free computer-to-computer telephone service, a headset and 30 minutes of Skype’s premium service, with which a user can call a landline or cell phone, company executives said.” [
More soap box derby action – “A lot has changed since the first Soap Box Derby in 1934. More girls are racing, wind-tunnel technology and computer modeling are the norm, and the cars are made mainly of plastic from easy-to-build kits…Over the last decade, Soap Box Derby racing has come barreling back thanks to a blend of tenacity, adaptation, renewed interest from national sponsors – including Nascar – and a yearning for nostalgia.” [
