This circuit was found in a Popular Electronics from the 90's. The CMOS integrated circuit used is not very common nowadays. The range depends on the infrared LEDs. R7 can be changed.
Published in 1988 in Hands-On Electronics, this circuit converts the 12 V of a battery into 120 V...
This 10 mA microammeter circuit can measure currents of 50 uA. The circuit is from a publication from the...
This receiver was found in an article in Electronics Now magazine in March 1994. The coils are...