This circuit was obtained from an Electronics Now from the 90's. It generates the dial signal and the ring tone, serving for testing as well as for demonstrations.
The circuit shown in figure 1 serves to control a servo motor with a current of up to 200 mA. The...
This is a circuit with a period component that consisted of a voltage reference. The circuit is...
This amplifier, suggested by National Semiconductor (Now Texas Instruments), has high input...