This double tone generator uses a specific integrated circuit, having been found in a 1977 CMOS Cookbook. The transistors can be the BC548.
Found in American documentation from the 90s, this circuit can be applied to other operational ones. We...
This charger can be used with one to four AA, AAA, C or D cells. The maximum current is given by R...
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...