An Automatic Switching Circuit of Dual Power Supply Controlled by Priority Power Supply

Abstract

The invention discloses an automatic switching circuit for dual power supply controlled by a priority power supply, comprising: a power supply L, a power supply H, a diode D1, a diode D2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, an optical-MOS switch S0, Solid state relay S1 and solid state relay S2. Realize the requirement of reliable work for a long time, without external control signal input, simplify the tedious control circuit; compared with the electromagnetic relay, the present invention does not need an additional coil protection circuit, which improves the inherent reliability; Shorter; at the same time, it is resistant to vibration and shock, has unlimited installation positions, and has good moisture-proof, mildew-proof, and anti-corrosion properties; it has the characteristics of low input power, high sensitivity, good electromagnetic compatibility, low noise and high work efficiency.

Description

technical field [0001] The invention belongs to the technical field of dual power supply switching, and in particular relates to a dual power supply automatic switching circuit controlled by a priority power supply. Background technique [0002] The commonly used power supply switching methods of the dual power supply system mainly include the following types: [0003] (1) Ordinary electromagnetic relay mode: the working principle of ordinary electromagnetic relay is that after the control signal is applied to the coil, the attraction force is generated through the coil and the magnet, and the relay contact is closed to conduct the circuit. When the control signal changes from high to low, the relay contact Spring back into place, breaking the circuit. When there is no independent control signal and only the power supply itself controls the power supply, the power supply also assumes the role of the control signal loaded by the coil. Since the coil of the electromagnetic re...

AI Technical Summary

Problems solved by technology

[0006] However, the difference between solid-state relays and electromagnetic relays is that there is no "single-pole double-throw" function, and the relays with higher power are all normally open functions. Only using the common solid-state relay circuit connection method cannot realize automatic and continuous switching power supply, that is, when two When switching power supplies, one must be disconnected first, and then the other must be closed. Two power supplies cannot exist at the same time.

[0007] The above control methods cannot fully satisfy the power supply switching system that has no external control signal, two power supplies exist at the same time, and there is a long-term power supply demand.

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