JPS63299521A - Radio reporting device - Google Patents

Abstract

PURPOSE:To improve the frequency stability and to simplify the circuit constitution for reduction of the cost with a radio reporting device, by obtaining a transmission frequency of an (n) multiple (n=2, 3, 4...) from the oscillation frequency of a crystal oscillation circuit serving as a source oscillator in a transmitter without using a frequency converting circuit. CONSTITUTION:A NAND circuit 10 which performs a gate action to transmit the output signal of a crystal oscillation circuit 2 to a switching circuit of the next stage is inserted into the next stage of a pulse data generating circuit 3 when the output pulse data signal of the circuit 3 is kept at H. Then a switching circuit 11 is added to control the ON/OFF states of the oscillating actions of an LC oscillation circuit 12 of the next stage by means of the output signal of the circuit 10. The circuit 12 oscillates at a frequency approximate to the transmission frequency. The oscillation frequency f0 of the circuit 12 is (n) times as much as the oscillation frequency fXT of the circuit 2. Thus the circuit constitution is simplified together with decrease of the number of parts and the cost reduction since no frequency converting circuit is used.

Description

Detailed Description of the Invention [Technical Field 1 of the Invention] The present invention is characterized in that the transmission frequency is n times the source oscillation frequency (n = 2, 3
．． The present invention relates to a wireless notification device having a transmitter configuration of 4...).

[Technical Background of the Invention] As shown in Fig. 3, a wireless notification device receives a security signal based on the output of a sensor, a gas leak detection signal, a fire alarm signal, etc. by radio on the notification device main body side using a wireless transmitter. configured to transmit to the machine.

Conventionally, as technology in this field, patent application No. 60-6
There were those described in No. 7469 and No. 60-67470. Hereinafter, its general configuration will be explained using figures.

FIG. 4 is a block diagram showing an example of the configuration of a transmitter of a conventional wireless notification device. In FIG. 3, and this pulse data generation circuit 3 outputs determined pulse code data upon receiving the notification signal, based on the clock signal of the crystal oscillation circuit 2 as a source oscillation circuit. The switching circuit 4 receives the output pulse data signal from the pulse data generating circuit 3, changes the bias of the next-stage crystal oscillation circuit 5, and controls its oscillation operation on and off. The crystal oscillator circuit 5 operates at an oscillation frequency fX during oscillation according to the control of the switching circuit 4 described above.
The output signal of T
. Note that 9 is a battery that energizes the entire circuit element.

FIG. 5 is a schematic diagram of a receiver corresponding to the transmitter of message ii in FIG. This receiver is constructed and operates in substantially the same manner as a general broadcasting receiver, and is placed close to the main body of the reporting device that provides housing information and the like. In the same figure, 20
is a receiving antenna that receives the radio waves carrying the transfer information from the transmitting antenna 8 and applies them to the high frequency amplification circuit 21, and the amplified signal here is converted into an intermediate frequency signal by the local oscillation circuit 23 and the frequency mixing circuit 22. This signal is amplified by the intermediate frequency amplification circuit 24 and then sent to the AM detection circuit 2.
AM detection is performed through 5. The configuration and operation up to this point are the same as a general receiver. Thereafter, this AM detection signal is shaped into a square wave by the waveform shaping circuit 26 and sent to the pulse data demodulation circuit 27. This pulse data demodulation circuit 27 is configured to compare the input pulse data signal with predetermined pulse data and send an output signal to the output terminal 31 when -M is reached.

Here, the operation of the reporting device configured as described above will be explained.

FIG. 6 shows the operation timing of the transmitter of the above-mentioned conventional device. When the notification signal is not input to the input terminal 1 of the transmitter, that is, when there is no security signal etc. (for example, the input is in the ILJ state), the output of the pulse data generation circuit 3 is in the "H" state, and therefore the output of the switching circuit 4 is in the "H" state. The base of the switching transistor Q becomes high and does not conduct.
Since no bias current is applied to the oscillation transistor 2 of the next-stage crystal oscillation circuit 5, oscillation is stopped. On the other hand, when there is a notification signal input to the input terminal (for example, input "H" state), pulse data is output from the output of the pulse data generation circuit 3.

When this output is in the rlJ state (b in the figure), the crystal oscillation circuit 5
A bias current is passed through the oscillation transistor Q2, and the circuit 5 oscillates at a frequency determined by the crystal resonator XT2 (C in the figure). This oscillation output is frequency-converted by the frequency conversion circuit 6, and the output frequency is T1" fxT2 (n =
= 2.3, .

However, since conventional wireless devices are configured as described above, a frequency conversion circuit is required in the transmitter to convert the oscillation frequency of the crystal oscillation circuit to the transmission frequency, and the circuit is complex and has a large number of parts. Therefore, there were drawbacks such as increased costs.

[Objective of the Invention 1] In view of the above circumstances, the present invention has been developed to increase the oscillation frequency of the crystal oscillation circuit as the source oscillator by n times (n=2.3, .1. ), the purpose of the present invention is to provide a wireless notification device that has high frequency stability, has a simple circuit, and is inexpensive.

1. Summary of the Invention In order to achieve the above object, the present invention provides a wireless reporting device that transmits a security signal based on a sensor output to the reporting device main body using a wireless transmitter at an appropriate transmission frequency. a source oscillation circuit, an oscillation circuit that oscillates at a frequency close to the transmission frequency, a gate means for transmitting the output of the source oscillation circuit to a subsequent stage based on the security signal, and an output signal of the gate means to transmit the output of the source oscillation circuit to the next stage. and a switching means for controlling the on/off operation of the source oscillation circuit.
It is configured to obtain a transmission frequency of n=2.3.4...).

[Embodiments of the invention] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a transmitter of a wireless notification device according to the present invention. In FIG. 1, the same elements as those in FIG. 4 are given the same reference numerals.

The wireless notification device of this embodiment differs from the conventional device shown in FIG.

When the output pulse data signal of this pulse data generation circuit 3 is in the 1) (J state, a gate-operated NAND circuit 10 is inserted that transmits the output signal of the crystal oscillation circuit 2 to the next stage switching circuit 11. A switching circuit 11 that controls on/off of the oscillation operation of the LC oscillation circuit 12 in the next stage is inserted in place of the switching circuit 4 in the conventional case, and the crystal oscillation circuit 5 in the conventional case is inserted in the next stage. Instead, an LC oscillation circuit 12 that oscillates at a frequency near the transmission frequency is inserted.Here, the LC oscillation circuit 12 as a single circuit, that is, when the switching transistor Qs of the switching circuit 11 is in the off state, The oscillation frequency when the oscillation transistor Q of this circuit 12 is normally biased and oscillates continuously is f0
*.

Further, the receiver has exactly the same configuration as the conventional one shown in FIG. 5, and is not shown here.

Next, the operation of the transmitter of the wireless reporting device configured as described above will be explained below with reference to the timing diagram of FIG.

As shown in FIG. 2, when there is no notification signal input to the input terminal 1 (for example, input "L1 state"), the output of the pulse data generation circuit 3 is in the ILJ state, and the output of the NAND circuit 10 is in the "H" state. Therefore, the switching 1-transistor Q5 of the switching circuit 11 is in an on state, and the emitter potential of the oscillation transistor Q6 of the LC oscillation circuit 12 is increased, and it is in a reverse bias state, so that oscillation is not possible. has stopped.

Next, when there is a notification signal input to input terminal 1 (for example, input 1) (J state), the determined pulse data is output from the output of pulse data generation circuit 3 (b in the figure), and the same output is When in IHJ state, crystal oscillator circuit 2 acts as a source oscillator
The oscillation output signal (a in the figure) passes through the NAND circuit 10 and is output in an inverted form (c in the figure). That is, when the output of the pulse data generation circuit 3 (b in the figure) and the output of the crystal oscillation circuit 2 (a in the figure) are both in the IHJ state, the output of the NAND circuit 10 is in the "L" state (c in the figure). , At this time, the switching transistor Q of the switching circuit 11 is turned off, and the oscillation transistor Q of the LC oscillation circuit 12 is normally biased and enters the oscillation state (d in the figure).
.

In the circuit configured as above, the oscillation frequency f0 of the LC oscillation circuit 12 is the oscillation frequency f0 of the crystal oscillation circuit 2.
It oscillates at n times XT (n=2.3.4...).

That is, f, = n'f) (T (4 fo lines), where fo is the oscillation frequency of the LC oscillation circuit 12, fxT is the oscillation frequency of the crystal oscillation circuit 2, and f0* is the oscillation frequency of the LC oscillation circuit 1.
The oscillation frequency of 2 alone is n=2.3.4...

Although the above embodiment uses a crystal oscillator XT as the source oscillator, any other oscillation element such as a ceramic oscillator may be used, and any circuit system may be used. .

Similarly, the circuit system of the LC oscillation circuit 12 may be any circuit system such as CR oscillation.

Similarly, the switching circuit 11 is also connected to the next stage oscillation circuit 1.
Any circuit system may be used as long as it is possible to control on/off of the oscillation.

Furthermore, although the output in this embodiment is a wireless type emitted from an antenna, the same effects as in the above embodiment can be obtained even if the output format is a wired type.

As described above, according to the present invention, the oscillation frequency of the crystal oscillation circuit is multiplied by n (n=2.3.4...) in the transmitter.
Since the structure is configured without a frequency conversion circuit to obtain the transmission frequency of , the circuit is simple and the number of parts is reduced, which has the effect of reducing the cost of the device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the transmitter of the wireless notification device according to the present invention, FIG. 2 is an operation timing diagram of the transmitter of the present invention shown in FIG. 1, and FIG. 4 is a block diagram of a conventional transmitter, FIG. 5 is a block diagram showing a receiver of a conventional wireless notification device, and FIG. 6 is a general diagram of a wireless notification device. 4 is an operation timing diagram of the transmitter of the conventional notification device shown in FIG. 4. FIG. 2... Crystal oscillation circuit 3... Pulse data generation circuit 7... Amplifier circuit 8... Tentenna circuit 9... Battery 10... NAND Circuit 11... Switching circuit 12... Oscillation circuit 25... AM detection circuit 26... Waveform shaping circuit

Claims (1)

[Claims] In a wireless notification device that transmits a security signal based on a sensor output to a notification device main body side using a wireless transmitter at an appropriate transmission frequency, the wireless transmitter includes a source oscillation circuit and an oscillation circuit that oscillates at a frequency close to the transmission frequency. and a gate means for transmitting the output of the source oscillation circuit to a subsequent stage when the security signal is present, and a switching means for controlling the on/off operation of the oscillation circuit at the next stage by the output signal of the gate means, A wireless notification device characterized in that a transmission frequency that is n times (n=2, 3, 4, . . .) the oscillation frequency of the source oscillation circuit is thereby obtained.