| 摘要 |
Embodiments of the present invention provide a power supply circuit and a telephone system, which are used to resolve a problem of high energy consumption of an existing telephone system for which power is supplied by using a telephone line of a single-circuit power supply type. The circuit includes: a control circuit, configured to output a control signal according to a voltage output by a primary charge clamping circuit and a preset voltage; a switch circuit, configured to be switched between switch-on and switch-off according to the control signal output by the control circuit; a charge and discharge circuit, configured to: when the switch circuit is switched on, acquire energy via the switch circuit, and store the energy; and when the switch circuit is switched off, inject energy into the primary charge clamping circuit and a secondary charge clamping circuit separately by releasing the stored energy; the primary charge clamping circuit, configured to output a voltage signal; and the secondary charge clamping circuit, configured to output at least one voltage signal, where when the power supply circuit is in a steady state, the voltage output by the primary charge clamping circuit is not equal to a voltage output by the secondary charge clamping circuit. |
