Found in a 90’s Popular Electronics, this circuit generates sinusoidal signals with frequency controlled by an input signal. C4, C3 and C1 together with R12 and R3 determine the frequency generated.
The indicated circuit uses an unusual buffer from National Semiconductor. The frequency is given by...
This battery charger is suggested by National and has a switch that turns it off when the battery is...
This circuit reinforces signals in a frequency range between 1500 and 2000 Hz for use in...