This digital to analog converter circuit was found in the March 1980 Radio Electronics magazine. The power supply should be symmetrical, and the digital controls can be TTL.
This circuit uses a JFET CA3140 operational amplifier to convert a low frequency sinusoidal signal...
This commercial radio for the AM band was sold in Japan in the 1960s. The circuit has an IF of 455...
In the figure we have a simple way to produce tone in a piezoelectric transducer. The frequency depends...