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Voltage Dividers

Communication circuits are often composed of a "chain" of devices and networks that passes electric signals from one device or network to the next. In many instances all the output voltage from one network is not needed by the next, or it may be advisable to make provisions for varying the voltage. Voltage dividers are used to select a fixed portion of an available voltage or to provide a variable voltage. These are often called potentiometers, a term erroneously used.1

An example of the use of a voltage divider is shown in Fig. 1. The voltage divider is a resistor with either fixed or movable contacts,1 In communication the driving circuit often can supply but little energy, and the driven circuit requires but little energy. In such instances the voltage divider would be a high resistance of perhaps

500,000 ohms. In some instances a voltage divider must be of low resistance (such as for terminating a transmission line).

voltage divider
Figure 1. A voltage divider is a resistor with fixed or movable contacts, often used as shown.

Last Update: 2011-05-30