This circuit was found in a 1966 EEE. What it does is it converts the logic levels of 0 V and +4 V into -6 V and +6 V. Some older type transistors can be replaced by modern equivalents.
We found this circuit in an 80's EDN. The circuit makes use of a MAX680, being given a table with...
This high-Q low-pass filter was found in the October 1990 issue of Radio Electronics magazine. The...
Found in an Elektor from the 90s, this circuit triggers a Sonalert-type buzzer when the sensor is...