This 3-transistor buzzer or buzzer is a classic type found in the July 1998 issue of Electronics Now magazine. The power rating depends on the output transistor.
This circuit was found in a documentation from the 60s. The drive transistor is a power...
With the original transistor of this 1976 circuit, the maximum load current is 15 A, but we can...
When the input voltage is higher than 2/3 of the power supply voltage the green LEDs glows. When...