This circuit, found in a 1958 magazine, is for reference only, since the components are not easy to find today. The transistors are germanium types and power supply is made by common cells.
This 1967 Electronics World circuit is suitable for frequencies up to 1 MHz. The setting applies...
This circuit was obtained from Maxim documentation. The circuit has 4.5 and 5.5V thresholds for...
This amplifier circuit for instrumentation was found in the manual of the used integrated circuit...