VTO ​​tamper alarm circuit

Abstract

The invention relates to a tamper alarm circuit for a doorphone. The tamper alarm circuit comprises a doorphone or entrance machine circuit, a tamper alarm oscillating circuit and a tamper detection and trigger circuit, wherein a power supply of the doorphone or entrance machine circuit is connected with the tamper alarm oscillating circuit, a call line of the doorphone or entrance machine circuit is connected with the tamper detection and trigger circuit, and the oscillating output of the tamper detection and trigger circuit is connected with the tamper detection and trigger circuit; and the tamper alarm oscillating circuit can generate oscillation when powered by the power supply, the tamper detection and trigger circuit is composed of a single-pole double-throw (SPDT) or double-pole double-throw (DPDT) tamper detection switch, a standby charging circuit and a call drive circuit, and energy storage of the first call can be achieved when tamper detection and call drive are achieved. By means of the tamper circuit scheme which is low in cost, simple and practical, the tamper alarm function of equipment such as doorphones or entrance machines without single chip microcomputers and power supplies usually can be achieved.

Description

technical field [0001] The invention relates to building intercom system equipment, especially for equipment requiring anti-dismantlement alarms such as door machines and stairway machines. Background technique [0002] At present, in the building intercom system, the anti-dismantlement of the door machine or the door machine and other equipment is mainly detected and processed by the single-chip microcomputer, and then the alarm output is output through communication or the ringing of the equipment. , but for devices that do not contain a single-chip microcomputer, the cost is relatively high, and it is basically impossible to implement on devices that usually do not have power supply. [0003] In addition, in the building intercom system, in order to save power and cost of the system, most of the door-to-door or stairway machines are designed with discrete components and usually do not have power supply. Machine or ladder machine power supply, less design with anti-disman...

AI Technical Summary

Problems solved by technology

[0002] At present, in the building intercom system, the anti-dismantlement of the door machine or the door machine and other equipment is mainly detected and processed by the single-chip microcomputer, and then the alarm output is output through communication or the ringing of the equipment. , but for devices that do not contain a single-chip microcomputer, the cost is relatively high, and it is basically impossible to implement on devices that do not usually have power supply

[0003] In addition, in the building intercom system, in order to save power and cost of the system, most of the door-to-door or stairway machines are designed with discrete components and usually have no power supply. Only when there is a customer call or user monitoring, the door-to-door Machine or ladder machine power supply, less designed with anti-dismantle function

In this case, it is difficult to use a general-purpose single-chip microcomputer to solve the anti-dismantlement problem, and the amount of modification is large and the cost is high.

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