This RF preamplifier for the 450 MHz band was found in an amateur radio documentation from the 1980s. The transistor supports an equivalent operating at the recommended frequency.
With this circuit it is possible to monitor the charge and discharge of a battery. The circuit is...
Found in 90s Radio Electronics, this shield can control high voltage loads in the power grid....
The duration of the output pulse in this circuit depends on C. This capacitor can have values in...