Found in a 1966 American publication, this circuit generates a 25 MHz rectangular signal for testing flip-flops. Transistors are from the era. No information is given about L1.
This alarm circuit was found in a 1982 publication. It uses components that can still be found...
This circuit has a voltage gain of 30 times and passband of 14 MHz. The circuit is from the 1974...
This High Side sensor with the L1637 was obtained from a Linear Technology 2005 own manual that...