Current Regulator Circuit

Yippee! I successfully remembered my training as an electrical engineering student, and built a current regulating circuit to guarantee constant illumination from an LED under varying supply voltages.

(application: RC car headlights)

I won't bore you with a circuit schematic ;-) but it involves two LEDs each having a Vf of 2.0 V and an If of 20ma, a 75 ohm resistor, and a 10k resistor (though it probably oughta be 1k). The resistor values need to be adjusted for the Vbe of the 2n3904 transistor (~0.75 V under these conditions), but the goal is to guarantee 20ma through the LED on the top, for a Vs of 4 to 6V.

Quick Drying Random Things

Ever need something dried quickly, but can't microwave it, stick it in the oven, or put it in the clothes dryer? Try this!

Just tape a hair dryer into the opening of a PAPER grocery bag, put the thing to dry inside, and partially tape it shut. Turn on the hair dryer, and wait a couple of minutes. Whala!!