JPH0710473Y2 - Fire sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a fire sensor.

[Prior Art] Some fire sensors detect the magnitude of a fire phenomenon such as smoke, heat, flame, or gas and output a signal corresponding to the detected amount to a receiver or a repeater. Also, the fire sensor
When outputting a signal corresponding to the detected amount as a digital signal, the fire phenomenon detection unit has an A / D conversion circuit for converting an analog signal into a digital signal.

By the way, in the conventional fire sensor, the A / D conversion circuit is always in the ON state because it is necessary to perform the detection at all times. That is, current is always supplied to the A / D conversion circuit. Therefore, there is a problem that the power consumption of the fire sensor is large.

In particular, as the number of lines increases and the number of fire sensors used increases, the power consumption of the entire system becomes very large, and the capacity of the battery for a power failure increases.

As a device for reducing the power consumption of a fire sensor, there is a device described in JP-A-58-223895. In this device, a receiver calls a terminal corresponding to the fire sensor, and a polling address and a self-address are used. When the and are matched, the switch circuit 17 is operated to supply the power supply voltage to the A / D conversion circuit, and thus, the power consumption is lower than that in the case where the power supply voltage is constantly supplied to the A / D conversion circuit. Contribute to savings.

However, in the above conventional example, when the polling address and the self address match, the power supply to the A / D conversion circuit is started and the A / D conversion is completed only after the transmission to the receiver is completed.
Power supply to the conversion circuit ends. Therefore, it is not necessary to perform A / D conversion from the end of the operation of converting the analog signal to the digital signal until the end of the transmission to the receiver, but the power supply to the A / D conversion circuit is performed. However, there is a problem that the power supply during this period is wasted.

[Object of the Invention] The present invention has been made in view of the problems of the above-mentioned conventional device, and an object of the present invention is to provide a fire sensor that can reduce the power consumption in a fire sensor that outputs a digital signal. It is what

[Embodiment of the Invention] FIG. 1 is a block diagram showing an embodiment of the present invention.

The fire sensor 10 includes a transmission / reception circuit 20 for exchanging signals with a receiver or a repeater, an instruction buffer 21 for holding an instruction from the receiver, and an address buffer 22 for holding an address received from the receiver. An address setting circuit 31 for presetting an address for each fire sense 10 and a power supply circuit 32 are provided.

The transmission / reception circuit 20 is an example of a transmission circuit that sends out the digital signal converted by the A / D conversion circuit.

The power supply circuit 32 includes an A / D conversion circuit 6 which will be described later when the address received from the receiver in the comparison circuit 30 matches the address set in the address setting circuit 31.
This circuit supplies power to 0. The address setting circuit 31 is composed of a ROM (Read Only Memory). Of course, another member such as a DIP switch may be used as the address setting circuit 31.

Further, the fire sensor 10 includes a timer 41 and a fire phenomenon detection unit that detects a physical quantity of a fire phenomenon and generates an analog signal output.
40, a hold circuit 50 that holds the analog data from the fire phenomenon detection unit 40, an A / D conversion circuit 60 that converts the analog data held by the hold circuit 50 into digital data, a CPU, etc. And a processing circuit 70 for processing.

The processing circuit 70 has storage means for updating and storing the digital signal output from the A / D conversion circuit 60. Further, the processing circuit 70 starts power supply from the power supply circuit to the A / D converter circuit when the polling address received from the receiver and the self address match, and the digital signal output from the A / D conversion circuit is output. It is an example of the control means for updating and storing the signal in the storage means, and stopping the power supply to the A / D conversion circuit when the updating storage is completed. Further, the processing circuit 70 is also an example of an output unit that reads out the digital signal updated and stored in the storage unit and outputs the digital signal to the transmission circuit.

When the address from the receiver and the address set by the address setting circuit 31 match, the comparison circuit 30 puts the processing circuit 70 into the run state (the operation unit is in the operating state), and both addresses match. If not, the processing circuit 70
Is placed in a wait state (the arithmetic unit is in a standby state).

Next, the operation of the above embodiment will be described.

FIG. 2 is a flow chart showing the reception interrupt operation in the above embodiment.

When a data signal composed of an address and an instruction is received from the receiver, the address in the received data is held in the address buffer 22 and a reception interrupt signal is output from the address buffer 22 (S1), the processing circuit 70 becomes the run state (S2), and the address held in the address buffer 22 and the address (self address) set in the address setting circuit 31 are compared in the comparison circuit 30 (S).
3). If the two addresses do not match, the next signal is received (S11, S1).

On the other hand, when both addresses match, the comparison circuit 30 outputs a match signal. When this coincidence signal is generated, the power supply circuit 32 is turned on (S4). Then, the A / D conversion circuit 60 starts conversion of analog data into digital data (S5).

Before the A / D conversion circuit 60 starts the conversion operation, the fire phenomenon detection unit 40 monitors the fire phenomenon and outputs analog data related to the fire phenomenon. This analog data is held in the hold circuit 50. There is. Also, the fire phenomenon detector
Timings of the hold circuit 50 and the hold circuit 50 are controlled by a timer 41.

Then, when the conversion operation from the analog data output from the hold circuit 50 to the digital data is completed, the digital data is read into the processing circuit 70 (S6).

The conversion operation is completed, the digital signal is stored in the storage means in the processing circuit 70, and then the power supply circuit 32 is turned off (S7). As a result, the power to the A / D conversion circuit 60 is cut off. Therefore, power consumption in the A / D conversion circuit 60 is not wastefully consumed when A / D conversion is not required. After the power supply circuit 32 is turned off, the processing circuit 70
Reads command data from the command buffer 21 (S8), and if the command is a digital data request, sends the read digital data to the receiver via the transmission / reception circuit 20 (S10).
Then, the processing circuit 70 automatically enters the wait state (S1
1) Then, wait for the reception interrupt signal.

As described above, the A / D conversion circuit 60 in the called fire sensor 10 is only available when there is a possibility that the receiver calls itself (the fire sensor 10) and the detection output is requested to be returned. Power is turned on.

The fire sensor 10 may be any one that detects smoke, heat, flame, gas or the like, and is not limited to a fire phenomenon.

[Advantages of the Invention] According to the present invention, the power supply to the A / D conversion circuit is stopped when the operation of updating and storing the digital signal output from the A / D conversion circuit is completed. It is not necessary to supply power to the A / D conversion circuit during transmission to the A / D conversion circuit, and the power supply time to the A / D conversion circuit can be reduced, thus reducing the overall power consumption of the fire sensor. It has the effect of being able to.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a flow chart showing the operation of the above embodiment. 10 ... Fire sensor, 30 ... Comparison circuit, 31 ... Address setting circuit, 32 ... Power supply circuit, 60 ... A / D conversion circuit.

Continuation of the front page (56) Reference JP-A-58-223895 (JP, A) JP-A-60-11995 (JP, A) JP-A-59-201193 (JP, A) JP-A-58-22430 (JP , A) Actual development 60-87038 (JP, U) Actual development 54-14628 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A fire phenomenon detection unit for detecting a physical quantity of a fire phenomenon and generating an analog signal output, an A / D conversion circuit for converting the analog signal output into a digital signal, and conversion by this A / D conversion circuit. A fire sensor having a transmission circuit for transmitting the generated digital signal, the fire sensor is provided between the fire phenomenon detection unit and the A / D conversion circuit, and temporarily holds the analog signal output of the fire phenomenon detection unit. A hold circuit; a power supply circuit for supplying operating power to the A / D conversion circuit; an address setting means for setting a self address; a comparison means for comparing the polling address received from the receiver with the self address; When the polling address received from the receiver and the self address are the same, the storage means for updating and storing the digital signal output from the A / D conversion circuit is the above power supply circuit. Then, the power supply to the A / D conversion circuit is started, the digital signal output by the A / D conversion circuit is updated and stored in the storage means, and when the update storage is completed, the digital signal is output to the A / D conversion circuit. CPU provided with control means for stopping power supply of
A fire sensor, comprising: a processing circuit including the above; and an output unit that reads out a digital signal updated and stored in the storage unit and outputs the digital signal to the transmission circuit.