With this circuit it is possible to obtain a higher voltage from a zener diode. The circuit is from a 1970’s EEE. The device used as a constant current source is uncommon today.
This well-known configuration, used in many car radios, is from the Philips Data Book of 1990. The...
With this circuit it is possible to expand the voltage range of a common multimeter, also...
This circuit for very long-time intervals was found in the March 1993 Radio Electronics magazine. Times...