Page 1135 - Basic Electrical Engineering

Figure 17.13 IC 555 timer is used as an astable oscillator

This type of oscillators find many applications like in quartz watch to keep
track of time in AM radio to create a carrier wave for the station, in
computers where a specialized oscillator called a clock serves as a sort of

pacemaker for the microprocessor, in wireless receivers and transmitters, in
cell phones, pagers, in music synthesizers etc.

17.8 IC VOLTAGE REGULATORS OR REGULATOR ICS

A voltage regulator converts a varying input voltage into a constant

‘regulated’ output voltage. Thus, a voltage regulator supplies a constant
voltage at the output regardless of the magnitude of load current supplied. IC
voltage regulators are relatively cheap as compared to regulators designed

using op-amps. IC voltage regulators are available in a variety of output
voltages. The LM 78 xx series of voltage regulators are designed for positive