Power transformer with DC leakage protection

Abstract

The invention discloses a power transformer with DC leakage protection. The power transformer comprises a shell. The shell is provided with a power input interface therein connected with the commercial power. The power input interface is connected in sequence with a DC change current circuit for converting an AC into a DC, a DC bidirectional leakage detection circuit, a power-off execution circuit, a filter circuit, a main power conversion circuit, and a power output interface connected with an electric appliance. An operation processing circuit for controlling the power-off execution circuitto disconnect when the DC bidirectional leakage detection circuit detects leakage is also connected between the DC bidirectional leakage detection circuit and the power-off execution circuit. The power transformer in the invention can perform leakage detection on positive and negative bidirectional currents of a high-voltage DC inside the power supply and control the power-off circuit to disconnect the power supply when the leakage occurs, thereby improving the safety of use.

Description

[technical field] [0001] The invention relates to a power transformer with DC leakage protection. [Background technique] [0002] In power converters and chargers, AC power is generally converted into DC power through ballast bridges and capacitors as follows figure 1 As mentioned above, as the mobile device charger turns into direct current after AC220 passes through the rectifier bridge and capacitor, this direct current contains a positive pole exceeding +110 volts relative to the ground and a negative pole exceeding -110 volts relative to the ground. When either of these two electrodes When a leakage occurs, the leakage circuit breaker in the commonly used distribution box may not be triggered for protection. This kind of DC leakage is even more dangerous when it touches the human body. [0003] In the existing power converters and chargers, most of their output terminals are independent, and there is only a very small distance between the weak current at the output ter...

AI Technical Summary

Problems solved by technology

[0003] In the existing power converters and chargers, most of their output terminals are independent, and there is only a very small distance between the weak current at the output terminal and the strong current at the input terminal, generally 7mm, and there is no other safety at the output terminal. Protect the circuit, so when the weather changes, water vapor freezes between the weak current and the strong current, or conductive debris, or even small animals crawl in and just fall between the weak current and the strong current, so that the output terminal is directly connected to the input terminal, As a result, the output port may be directly connected to the mains. At this time, when the human body touches the output port, there is a potential safety hazard of electric shock

[0004] On the other hand, existing leakage circuit breakers cannot detect DC leakage well

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