SU762019A1 - Alarm device - Google Patents

Description

The invention relates to systems • Alarms, intended for alarms and can be used in security and fire alarms.

Known devices for alarm, containing linear cells, including measuring bridges, powered from a constant voltage source with measuring elements-10 m in diagonals, connected by communication lines with the measured resistances placed in protected objects [!].

The disadvantages of the known devices are the possibility of unlocking it without triggering an alarm by switching the resistance measured in the protected object, measured by a bridge, to a constant voltage source outside the protected object, 20 the value of which is equal to the voltage drop on the variable resistance, as well ότ of the source of • direct current does not allow to reduce the power consumed by the device without significant changes in the parameters of the elements forming m stop

The closest technical

essence to the proposed is,.

2

a device for alarming, containing measuring bridges according to the number of monitored objects with sensors in the arms mounted on objects and measuring elements in one diagonal of bridges, pulse generators connected to the trigger inputs connected through an integrator with other diagonals of measuring bridges [2].

The disadvantages of this device include the relatively low reliability of the device, which significantly depends on the magnitude of the response voltage of the measuring element, as well as the impossibility of reducing the power consumption of the bridges without changing their basic parameters.

The purpose of the invention is to increase the reliability of the device and reduce power consumption.

The goal is achieved by the fact that a rectangular pulse generator is installed in the device, connected between the voltage source and other diagonals of the measuring bridges, and the rectangular pulse generator is made on the master pulse generator, binary counter, decoder and switch 762019

To the torus, the output of the master pulse generator is connected to the input of a binary counter, the outputs of which are connected via a decoder to the separate inputs of the switch.

FIG. 1 is a block diagram of an alarm device? in fig. 2 - time diagrams of his work.

The device contains' resistors 1, located in protected objects 2, communication lines 3, measuring bridges 4 with measuring elements 5 included in one of their diagonals, connected by other diagonals to a voltage source b through a generator 7 direct coal pulses consisting of a master oscillator 8 pulses connected to the input of the binary counter 9, the outputs of which through the decoder .10 are connected to the corresponding inputs of the switch 11 and the indicator 12 alarms.

The device works as follows.

In the initial state, the master oscillator 8 generates a continuous sequence of pulses 1C (figure 2). The pulse repetition period from the master generator of the 8 pulses must be longer than the response time of the measuring element 5, but must also provide the time value T _MF (Fig. 2) of the binary counter 9 overflow at least twice the minimum time of the alarm signals from the protected objects

2. The pulses from the output of the master oscillator 8 pulses and (Fig. 2) are counted by a binary counter 9. The decoder 10 of the state of the binary counter 9 with its outputs sequentially controls the corresponding inputs of the switch 11, providing a serial connection of the measuring bridges 4 to the voltage source b for the binary time counter 9 in the corresponding states and _g , i ^ and u ₄ (Fig. 2). When equilibrium measuring bridges 4, the voltages in their diagonals are zero and do not depend on whether or not bridge 4 is connected to voltage source 6.

When an attempt is made to penetrate a protected object 2 and an alarm is received from object 2, the value of resistor 1 Й „ _Ω (Fig. 2) increases (or decreases) and the equilibrium of the corresponding measuring bridge 4 is broken, during the next connection by switch 11 of measuring bridge 4 to source 6 voltage and _d (FIG. 2) corresponding to the diagonal of the measuring bridge 4 to the input of the measuring element 5 is energized and ₅ (FIG. 2) which causes the measuring element at the inlet 5 the alarm which arrives n Ί2 input indicator alarms.

When connecting to line 3 of the external voltage source connection +

(Fig. 2) in order to block the resistor 1 in the diagonal of the corresponding measuring bridge 4 to the input of the measuring element 5, a voltage is applied (Fig. 2), which causes an alarm signal at the output of the measuring element 5. At the time of the next connection of the measuring bridge 4 to the voltage source 6 and ₄ (Fig. 2), in the case of coincidence of the polarity of the voltage falling on the resistor 1 and the voltage connected with the target ⁷ deblocking, the value of ΙΙγ (Fig. 2) at the input of the measuring element 5 decreases .

Powering the device from a rectangular pulse generator significantly reduces the sensitivity requirements of the measuring element and the power consumed by the bridges in the process of constant monitoring of the value of resistor 1, and also makes it difficult to unlock the device by external voltage sources. In addition, the pulsed power supply of measuring bridges 4 creates additional difficulties when trying to unlock a device by changing the parameters of link 3 within certain limits, since the device will react to changes in capacitance and inductance. The implementation of the rectangular pulse generator in the form of a ring switch-distributor connected to the measuring bridges 4 to the voltage source 6 alternately reduces the power requirements and dynamic characteristics of the power supply. Unlocking the device with an external power source is difficult because it requires a square wave generator that operates synchronously with the square wave generator of the device. The timing of the pulses of both generators must match. If these parameters do not match, in the gap between the pulses of the bridge in the controlled circuit there will be a voltage and *, (Fig. 2), and a voltage and ₇ will be applied to the input of the measuring element (Fig. 2).

The voltage at the input of the measuring element 5 has a larger value than in the known device. Therefore, in the proposed device can be applied less sensitive measuring elements.

Claims (2)

Claim 1. A device for alarming, containing measuring bridges, in the arms of which are installed sensors, and in some diagonals measure762019 The body bridges include measuring elements, the outputs of which are connected to an alarm indicator, and a voltage source, distinguish them with the fact that, in order to increase the reliability of the device and reduce power consumption, the device has a square-wave generator connected between the voltage source and other diagonals measuring bridges. 2. Device by π. 1, characterized in that the square wave generator contains a master pulse generator, binary the counter, the decoder and the commutator, the output of the master oscillator is connected to the input of a dual counter, the outputs of which are connected to the separate inputs of the switch through the decoder.