We find this circuit in an Electronic Design of the 90s. The used integrated circuit admits equivalents and next to the diagram are given the formulas for the calculation of the components used.
This circuit incorporates the passive control of the previous circuit and was also found in the...
I found this circuit on a December 1976 Radio Elettronica. The Italian magazine no longer exists, but...
This circuit is like the previous one except that it can be triggered electronically. The circuit is...