This circuit was found in a Popular Electronics from the 90's. The transistors are general-purpose types and the loaded load depends on the voltage and must have a maximum current of 100 mA.
This circuit was obtained in Radio Electronics from the 90s. The integrated circuit is uncommon...
This 4-digit digital clock for hours and minutes with CMOS integrated circuits was found in a 1995...
This circuit is indicated to operation with low intensity sources such as electret microphones and...