This circuit was found in 1980s Radio Electronics. The circuit includes the power supply. The ICL8038 circuit was very common at the time in this type of application.
This circuit was found in a 1967 American documentation. The switching diode (tunnel) used is an...
This circuit was found in a 1975 documentation. Operational amplifiers must have a symmetrical source and...
The diagram shown was found in a 1975 active filter manual. The tuned frequency range depends on...