Automatic power source turning-off circuit

Abstract

The invention discloses an automatic power source turning-off circuit. The output end of the automatic power source turning-off circuit is connected with a load; when the load works normally, a secondswitch tube and a first switch tube are in saturated on states, a relay works normally, a normally-open contact is closed, and the normal power supply of a power source loop is ensured. A first capacitor is charged through a second switch tube; when the load is disconnected, the second switch tube is turned off; due to the discharge effect of the first capacitor, the first switch will further remain an on state on; only after first delay time passes, the first switch tube is turned off; the relay K1 is turned off; and the entire power source loop is cut off; and therefore, the automatic complete turning off of a power source can be realized. The automatic power source turning-off circuit has the advantages of low cost, simple control and high reliability.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to an automatic power-off circuit. Background technique [0002] In the prior art, people often forget to turn off the power switch when they have finished using the electrical appliances, and when they forget to turn off the power switch, it will not only cause a waste of electric energy, but also have many potential safety hazards, which people do not want Yes, it is absolutely not allowed. Therefore, in order to ensure the safety of electricity use, ensure the safety of the circuit, and save electric energy, many scholars in the prior art have proposed several methods for this technical problem, but the existing methods may have problems with complex circuits or cost. High problems, or low reliability problems, etc., so the effect is not ideal. [0003] Aiming at the current technical problem that the power supply cannot automatically and reliably shut off the total powe...

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