This circuit was obtained in an Electronics Now from the 90s. The circuit uses operational amplifiers from the time and the indicator is of the Sonalert type with internal oscillator.
This circuit was obtained from a 1967 General Electric manual. The circuit uses components of the time,...
This circuit uses an amplifier from National Semiconductor, uncommon nowadays. The numbers in...
This circuit is powered by the source of the equipment under analyze. We found this configuration in a 1974...