B21126E)
This circuit was taken from an old Popular Electronics. The circuit can have its frequency changed from an external signal. The center frequency is given by C1.
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...