This simple low current circuit was found in a Radio Electronics magazine from August 1960. The circuit does not use transistors in regulation, but only zeners directly.
Found in Radio Electronics from the 90s, this circuit uses a thermistor as a sensor that can have...
The scale of this scale uses LEDs, and its accuracy depends on the number of LEDs. We found this...
Found in American documentation from the 90s, this circuit generates sound bursts according to the...