This circuit was found in a publication by Edelman from 1924. The power comes from the battery and the listening is through a high-impedance headphone.
This timer charges the C1 capacitor with constant current, thus determining the SCR triggering time that...
In the circuit of the figure we used a potentiometer of 1 k ohm. We can use a larger...
Mouser Electronics is offering the new ultra-low power microcontrollers CC26xx SimpleLink ™ for...