JPS58101395A - Burglar-proof/disaster prevention alarm - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] This invention relates to a crime prevention/disaster prevention alarm device that performs multi-point detection in a single line by assigning resistors to sensors and issues an alarm based on activated sensors. .

Due to the current diversification of society, it is possible to quickly detect abnormality points such as crime prevention and disaster prevention in buildings, apartments, underground malls, etc., as well as abnormality points in plant equipment, power generation and substations, etc., and to detect abnormal situations with high reliability. There is an increasing need to accurately discover the

Conventionally, various devices have been proposed to meet the above requirements. For example, conventional single-line crime prevention and disaster prevention alarm systems,
- A large number of sensor contacts are connected in parallel to the line, and when any sensor is activated, the alarm device is activated, and it is necessary to check all sensors on one line each time an alarm is issued, so there is a problem in speed. There is also the problem that it is troublesome.

In addition, in order to solve the problem of this - line system, there is a method that allocates one line to each sensor, but this requires a large number of lines and has problems with construction costs, etc., so it is rarely used. do not have. Furthermore, some devices are equipped with a frequency generator etc. that is operated by each sensor, but this requires a frequency discrimination circuit to be installed in addition to a frequency generator for each sensor, which is expensive and may cause malfunction due to radio waves, etc. be.

The present invention was made in view of the above circumstances, and its purpose is to provide a one-line crime prevention/disaster prevention alarm device that is inexpensive and highly reliable.

The present invention will be described below based on embodiments shown in the accompanying drawings.

As shown in the figure, three sensors la, 1b, an IC, and a variable resistor 2 are connected in series, and each sensor 1a, 1b.

Detection resistor 3 ” + 3 bT 3 C for each 1C
The single-line detection means 4 is configured by connecting the following in parallel:
The predetermined current is iiT]! The detection voltage ■ generated in the detection means 4 by energization is detected by the analog-to-digital converter (
The signal is input to an AD converter (hereinafter referred to as an AD converter) 5, and is converted into a binary digital signal. In addition, the above-mentioned sensors la, ib,
The IC opens its contacts in the event of an abnormality.

The AD converter 5 has a detection voltage V and a reference voltage V+.

V2. Nine comparators 5a, 5b, .
Comparators 5a, 5b, . . . generate a high-level comparison signal when the detected voltage is larger than each reference voltage, and convert the inputted detected voltage ■ into a digital signal. Each reference voltage Vl, V2... is connected to 10 reference resistors 7.
a, 7b... are connected in series to a reference voltage generator 8,
This is the voltage generated at each connection point of each reference resistor 7a, 7b, . Note that this AD converter 5 is connected to each sensor 1a.

In the case of detecting only whether or not 1b and 1C are operating, seven comparators are sufficient, but in this embodiment, the detection means 4
Nine comparators are required because the disconnection and two-wire short circuit of the detection means 4 are detected by the voltage generated from the detector.

The code converter 9, which receives the digital signal from the AD converter 5, has one more signal than the number of sensors 1a, lb, and 1c.
Sensor alarm drive units 10a, 10b, 1 emit a large number of signals, and drive alarm devices (not shown) corresponding to the respective sensors la, lb, and ic using these output signals.
0C and a short circuit alarm drive section 11 that drives a two-wire short circuit alarm device (not shown). This code converter 9 is activated when a low-level signal is generated from the comparator 6a of the ADi converter 5, and becomes inactivated when a high-level signal is generated.

10b, 10C and 11 are stopped. Incidentally, when this comparator 6a is emitting a high level signal, it activates a wire breakage alarm drive unit 12 that drives a wire breakage alarm device (1 is not shown).

Note that the variable resistor 2 is for adjusting the detection voltage (2), and may be a fixed resistor. In addition, the above reference resistance 7
If the resistance value of j is k, then the resistor 3b is 4R1, the resistor 3C is 8R1, and the rest are 2R.If n sensors are used as the detection means, the resistance value of the resistor corresponding to each sensor is 2R, 2'R, 23k.

...21, the number of reference resistors is (2"+2), the resistance value of the grounded resistor is k, and the other reference resistors are 2R.Here, the resistor corresponding to each sensor is The resistance value is not limited to the above value, and any resistance corresponding to the sensor can be selected.
The combined resistance value of the combination is made different from the combined resistance value of other combinations, the voltage detected by that combination is stored in the storage device, and the detected voltage is compared with the stored value. Alternatively, a drive unit corresponding to the sensor may be actuated to issue an alarm.

The present invention has the above-mentioned configuration, and its operation will next be explained based on FIG. 2.

FIG. 2 shows the states of sensors la, 1b, 1c, the outputs of comparators 5a, 5b...61 of AD converter 5, and the operating states of drive units 10a, 10b, 10(, 11, 12(7)). In this figure, the drive unit is activated to issue an alarm when the signal is H.

First, all sensors l'a, 1b, lc
If the comparator 51 is not operating, all the contacts are closed, so only the comparator 51 emits a high level signal, and the code converter 8
is in the operating state, and the drive units 10a, 10b, 10C.

11.12 is inactive and no alarm is issued.

Next, when at least one of the sensors la, lb, and lc operates and opens the contact, a signal is emitted corresponding to that sensor, so the drive unit 10a corresponding to the activated sensor,
10b and 10C each issue an alarm, and the point where the abnormality has occurred can be confirmed. Furthermore, if a disconnection occurs in the detection means 4, the detection voltage (■) becomes extremely large and all the comparators 5a, 5b
... emits a high level signal, and the code converter 81i
, the drive unit 12 is activated, and the detection means 4 is alerted to the occurrence of a disconnection. Furthermore, when the detecting means 4 short-circuits two wires, the driving unit 11 activates the alarm device, and the short-circuit abnormality can be confirmed.

As described above, the present invention provides a single-line detection means in which sensors are connected in series and a resistor is connected in parallel to each sensor, and the resistance value of this detection means is detected, thereby inexpensively and reliably. This has the advantage of being able to confirm which sensors are activated.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an example of the present invention, and FIG. 2 is a drawing showing a truth table based on FIG. 1. la, 1b, 1c...sensor, 2...variable resistor,
3... Detection resistor, 4... Detection means, 5... AD converter, 6a. 6b... Comparator, 7a, 7b... Reference resistance, 8...
・Reference pressure generator, 9... code converter, 10a, 10
b, IOC...Sensor alarm drive section, 11...Short circuit alarm drive section, 12...Disconnection alarm drive section.

Claims (1)

[Claims] a single-line detection means in which a plurality of sensors are connected in series, and each sensor is connected in parallel with a resistor having a different resistance value;
It consists of a conversion means that detects the resistance value of this detection means and outputs it as a digital signal, and a signal converter that converts the signal from this conversion means into a signal corresponding to each of the above sensors, and is a combination of resistances arbitrarily combined. A crime prevention/disaster prevention alarm device characterized in that the resistance value is different from the combined resistance value of other combinations, and the alarm device corresponding to each sensor is controlled by the output signal of a code converter.