Power supply circuit of subscriber terminal

Abstract

Abstract PURPOSE:To eliminate the need for the operation of a commericial power switch at each transmission and response without large power consumption, by using a CPU supplied with a standby power supply as a control circuit at call incoming and off-hook. CONSTITUTION:A commercial power supply is normally connected to an input of a backup power supply 208 regardless of the switching state of a switch 200 and a relay contact 211, and an operation power is always applied to a CPU210 and a bell signal detection circuit 217 with the power supply 208. Thus, the CPU210 monitors the output of a hook switch 212 and the circuit 217 through a control bus 209 to execute specified control.

Inventors

• 👤 Kunio Nagashima
• 👤 長島　邦雄

Bibliographic Details