Found in a Hands-On Electronics from the 90s, this circuit produces the dial tones of an old telephone. The integrated circuit used is uncommon today.
By polarizing the reference with the supply voltage we can use these amplifiers in logic circuits....
The circuit we present was found in an English magazine from 1973. The complementary pair of power...
Found in an American documentation from 1969, this circuit operates at a frequency determined by the...