This circuit was found in a 90s Popular Electronics. The circuit uses components from that time, intended to receive signals in the range of 150 to 250 kHz.
This alarm circuit was found in the July 1992 Radio Electronics magazine. The circuit uses a small...
Found in a Philips publication from the 1970s, this circuit uses a DO040, which is difficult to obtain...
This simple nicad battery charger uses a current regulator with the LM350. This integrated circuit must be...