Theftproof and alarm device of power transformer

Abstract

The invention discloses a theftproof and alarm device of a power transformer, comprising an alarm circuit, an alarm connected with the alarm circuit and a detection circuit connected with the alarm circuit. The detection circuit comprises a multivibrator circuit, a power supply circuit and a comparison circuit. Both the multivibrator circuit and the comparison circuit are connected with the power supply circuit. The invention has the advantages that no false alarm is generated; the device is capable of guarding against thefts whether the power transformer is electrified or not; the installation is convenient, i.e. the device can be directly mounted on A, B, C, N wire posts at the lower voltage side of the transformer; and the theftproof performance is reliable because a connecting wire of the alarm must be cut when the transformer is stolen.

Description

technical field [0001] The invention belongs to alarm equipment, in particular to an anti-theft alarm device for a power transformer. Background technique [0002] In the state of complete power failure of the transformer, how to realize the anti-theft of the transformer? At present, transformer anti-theft devices on the market mainly adopt the method of winding a sensor with a transformer. When the transformer is stolen, the sensor wound on the transformer is open circuit or short circuit, at this moment, the alarm will send out an alarm signal. However, this design has the following disadvantages: under normal circumstances, because the sensor and the connection itself do not have strong AC current, it is easy to be dismantled and modified, resulting in false alarms; if illegal personnel increase the length of the transformer winding wire in advance, the winding wire on the transformer If the transformer falls off and the transformer is stolen, there will be no alarm; be...

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Problems solved by technology

However, this design has the following disadvantages: under normal circumstances, because the sensor and the connection itself do not have strong AC current, it is easy to be dismantled and modified, resulting in false alarms; if illegal personnel increase the length of the transformer winding wire in advance, the winding wire on the transformer If the transformer falls off and the transformer is stolen, there will be no alarm; because the sensor and the connection wire are exposed to the harsh outdoor environment for a long time, the wire winding on the transformer is easy to age and cause false alarms; because the sensor is wound on the transformer shell, the normal temperature of the transformer is 20 °C ~70°C, the winding is more likely to cause rupture and collide with the transformer shell and cause false alarms; if it is not repaired in time, the internal damage of the alarm will lose the alarm function

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