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Home Telephone Exchange Service and Systems Simple Telephone Systems
 
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Simple Telephone Systems

A simple two-way telephone circuit is shown in Fig. 1. This circuit is objectionable because of the losses offered by the unused transmitter and receiver to the direct-current component for the transmitters and to the alternating-current speech component. Transmitters and receivers are often connected in series for interphones such as those used in apartment houses.

Two transmitters and two receivers could be connected in parallel to a line and battery as indicated in Fig. 2. This arrangement will give two-way conversation, but it also is inefficient. Under some conditionsref.2 its use may be more efficient than that of Fig. 1.

Figure 1. A simple series telephone circuit.

Figure 2. A simple parallel telephone circuit.


Home Telephone Exchange Service and Systems Simple Telephone Systems

Last Update: 2011-05-30