This Philips circuit of the 70's makes use of components of the time. The DZD40 is an uncommon integrated circuit today.
This limit alarm was found in a 1980s US documentation. Comparators can be equivalent and the...
Found in a RE Experimenter Handbook from the 90s, this circuit is intended for the use of LEDs in...
This circuit is from an American documentation from the 90s. The transistors are of power and must be...