This Japanese radio is from the 60s, presenting excellent sensitivity and an output power of 100mW with 6 V power from ordinary batteries. The circuit is of the superheterodyne type.
This 2001 CMOS digital circuit draws numbers from 00 to 99 and can be expanded. However, it does...
This filter was found in an old publication from 1977. The circuit must use a simple two-voltage source...
This circuit beeps when the sensor is triggered by the opening of the freezer door or other...