This sound intensity meter was found in a 90s Elektor. The circuit uses an integrated device from the time that is not common today. The indicator is a milliammeter.
Found in Motorola's 1965 manual, this full-wave dimmer controls a load that depends on the used...
The two adding and differentiating circuits with operational amplifiers given below were obtained from...
This sophisticated circuit was found in the November 1978 issue of Radio Electronics magazine. Based on...