JPS6225400A - Storage time measuring apparatus - 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 [Technical alter ego] The present invention relates to an accumulation time measuring device that can accurately and easily measure the accumulation time of an accumulation type photoelectric smoke detector.

[Background technology]

Conventionally, when measuring the accumulation time of a storage-type photoelectric smoke detector whose current consumption increases during the storage period using a smoke sensitivity test device at the installation site, the storage-type photoelectric smoke detector After connecting the sensor washing ammeter in series and turning on the smoke sensitivity test device a, the time from the timing when the above current consumption increases (accumulation start) until the accumulative photoelectric smoke detector operates (accumulation ends) was measured with a stopwatch, etc., and the time was taken as the accumulation time. However, with this conventional method, it is not only difficult to measure the accumulation time accurately due to oversights in the timing of increase in current consumption, lag in the timing of stopwatch operation, etc. If accumulation is interrupted midway through once accumulation starts for some reason, there are problems such as time measurement becomes complicated, and this is not a realistic method for measuring accumulation time at the installation site. There was a point.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide an accumulation time measuring device for an accumulation type photoelectric smoke detector that can easily measure accumulation time even at the installation site. .

[Disclosure of the invention]

The accumulation time measuring device of the present invention includes a current detection resistor connected between a test terminal of a smoke sensitivity test device and a measurement terminal connected to the measurement terminal, and a differential amplifier circuit that differentially amplifies the terminal voltage of the current detection resistor. and two comparison circuits inputting the output voltages of the difference 1 dl amplification circuit, and the comparison circuits operate at different comparison levels,
A pulse generation circuit that generates a pulse of a constant width based on the output of a comparison circuit that has a low comparison level, and a timer circuit that starts timing with the output of the pulse generation circuit, and the timer circuit has a high comparison level. The time measurement is completed based on the output of the comparator circuit and the time is measured.

Embodiment FIG. 3 shows a block circuit diagram of an example of a storage type photoelectric smoke sensor S which is a measurement target of the storage time measuring device M of the present invention. To describe its general structure and operation, it receives voltage supply through a constant voltage circuit VR and a current limiting circuit CL, receives light from a light emitting element (not shown) that emits light intermittently, and accumulates smoke when it detects smoke. When the smoke detection circuit SC that generates the start signal, the switch-J circuit SW provided between the input of the constant voltage circuit VR and the ground, and the accumulation start signal of the smoke detection circuit SC are input, a constant signal is generated. a storage circuit ST that generates a drive signal for driving the switching circuit SW after a storage time of The transistor Tr is turned on for the above accumulation time, and by utilizing the fact that the current consumption T of the accumulation type photoelectric smoke detector S increases to I+Io during the accumulation period, the accumulation state is determined by increasing the current. The aim is to detect the

FIG. 1 shows a block circuit diagram of an accumulation time measuring device M according to an embodiment of the present invention, and a block circuit diagram of a conventionally used smoke sensitivity testing device T. First, the smoke sensitivity test device T is equipped with a DC power supply E and a load relay Ry (
The above constitutes a substitute for the receiver) and the storage type photoelectric smoke detector S are connected in series with test terminals T+ and T2, and the test terminals 'L and T2 are normally equipped with an ammeter. The connection is made, and the time at which accumulation is started is detected by the increase in this current value.Furthermore, the switching circuit SW shown in FIG. The end of accumulation was detected when the resistance of the coil increased to a value determined by the resistance of the coil, and the above-mentioned time interval was measured by a person using a stopwatch or the like to determine the accumulation time. The accumulation time measuring device M of the present invention is a device that can measure the accumulation time naturally accurately and easily, and one embodiment thereof is as shown in FIG. T.I.
, a current detection resistor Rc connected between the measurement terminal Ml and Δ12 connected to T2, a differential amplifier circuit 1 that differentially amplifies the terminal voltage of the current detection resistor Rc, and a differential amplifier circuit 1 that differentially amplifies the terminal voltage of the current detection resistor Rc. It is equipped with two comparison circuits 2 and 3 that receive an output voltage as input, and the comparison circuits 2 and 3 operate at different comparison levels, and the output of comparison circuit 2 having a lower comparison level generates a pulse of a constant width. and a timer circuit 5 that starts time measurement with the output of the pulse generation circuit 4, and the timer circuit 5 ends the time measurement with the output of the comparator circuit 3 having a high comparison level and measures the time. It is configured to do this. In this embodiment, the differential amplifier circuit 1 includes two operational amplifiers Al and A2 to form a two-stage differential amplifier, and an operational amplifier A3 at the output stage.
The comparator circuits 2 and 3 are composed of open collector comparators C1 and C2, and the comparator circuit 2 has a steresis 1-
It is composed of a Rinopul monostable multivibrator MM. Figure 2 shows the bond accumulation time measuring device fffi of this embodiment.
This figure shows the main part of tie 3':) ditisate, and the operation of this embodiment will be explained below based on FIGS. 1 and 2.

The current consumption current IT of the storage type photoelectric smoke detector S flows through the current detection resistor Rc of the storage time measuring device M (the resistance value is approximately the same as the internal resistance of the ammeter)
(abbreviated as ) is extracted as a voltage signal by the differential amplifier 1. The storage type photoelectric smoke detector S mentioned above is
Since it includes a light emitting element of LEDA4 that emits light intermittently with a time period T, the current consumption IT increases during the time period T, and the second
Since the waveform is as shown in Figure (a), the voltage signal described above also has a similar waveform. Now, at time T1, suppose that the smoke detection circuit SC shown in FIG. 3 detects smoke generated for testing (or something that scatters light from a light emitting element), and the storage circuit ST starts to store it. For example, the comparator circuit 2 having a low comparison level operates, and the output changes to low level as shown in FIG. 2(b). The pulse generating circuit 4 operates using the fall of the output of the comparator circuit 2 as an active edge to generate a pulse having a time width τ. At the rising edge of this output pulse, the timer circuit 5 starts measuring time. By the way, the above-mentioned time width τ is set so that the relationship T<τ<2T holds true with the time period T of light emission, and the pulse generation circuit 4 is a monostable multi-channel hybrid circuit (as described above). Since it is composed of an S ibrator MM, once it is triggered, if it is triggered again within the time τ, the output remains constant without changing by the amount of time τ. Therefore, as shown in FIG. 2(c)K, time T
At + + T, the monostable multivibrator MM of the lid couple receives a trigger again, so its output remains at a high level. After that, by the time the accumulation is completed due to smoke reduction, etc. (the comparator circuit 3 is not in operation), the output pulse of the comparator circuit 2 is interrupted, so the retriggering is disabled after a time τ from the second trigger. The output of the monostable multibyte generator M becomes 0-level, and
When the signal falls, the timer circuit 5rri is reset as shown in FIG. 2(e). In other words, the above measurement time is the value when the accumulation is interrupted midway through the accumulation.
It is not the accumulation time value, so it is reset. Next, at time T2, the storage starts again, and this time it is assumed that the storage reaches the end. As mentioned above, the output of the comparator C1 of the comparator circuit 2 changes at time T2, which causes the output of the monostable multi-byte generator MM to become high level, and at this rising edge, the timer circuit 5 is activated. Start operation. Thereafter, the lid couple monostable multivibrator MM receives a trigger every time T (as shown by the broken line in FIG. 2(c)), so its output continues to maintain a high level. Then, at time T3,
When the storage type photoelectric smoke detector S operates (that is, the switching circuit SW in FIG. 3 is turned on) and the consumption current IT increases to the operating current value as shown in FIG. 11/ is operated and its output is the second
The timer circuit 5 changes as shown in FIG. (d) K, and at the falling edge, the timer circuit 5 stops measuring the time and ends the measurement of the accumulation time. Note that after this, the timer circuit 5 is reset after a time τ. As is clear from the above explanation (7), the accumulation time measuring device M of this embodiment has a power consumption of
Since it is taken out as the terminal voltage of the current detection resistor Rc, the accumulation time can be automatically measured without affecting the function of the smoke sensitivity test device T, and the monostable multi-tS generator of the lidrica can be easily measured. By starting and resetting the timer circuit 5 with the output of the MM, if the accumulation is interrupted during the accumulation, this measurement data can be eliminated and the accumulation time determined by correct measurement later can be obtained. At the installation site, the conventional smoke sensitivity measurement test only needs to be performed using the accumulation time measuring device M of the present invention instead of the conventionally used ammeter, and there is no need for a stopwatch, etc., and the test is automatically performed. Accumulation time can be measured accurately and easily.

〔Effect of the invention〕

The accumulation time measuring device of the present invention includes a current detection resistor connected between a test terminal of a smoke sensitivity test device and a measurement terminal connected to the measurement terminal, and a differential amplifier circuit that differentially amplifies the terminal voltage of the current detection resistor. , comprising two comparator circuits inputting the output voltage of the differential amplifier circuit, the comparator circuits operate at different comparison levels, and the output of the comparator circuit having a lower comparison level generates a pulse of a constant width. The present invention includes a pulse generation circuit that generates a pulse, and a timer circuit that starts time measurement using the output of the pulse generation circuit, and that the timer circuit ends the time measurement based on the output of the comparison circuit having a high comparison level and performs time measurement. This feature allows automatic measurement of the accumulation time of accumulation-type photoelectric smoke detectors, which consume more current when accumulation begins, without affecting the functions of conventional smoke sensitivity test equipment. Moreover, it has the advantage that it can be carried out accurately and easily.

[Brief explanation of drawings]

Fig. 1 is a block circuit diagram of an embodiment of the accumulation time measuring device of the present invention, Fig. 2 is a tie-three chart of the main parts of the same as above, and Fig. 3 is an example of an accumulation type photoelectric smoke detector. 1 is a differential amplifier circuit, 2 and 3 are comparison circuits each having a different comparison level, 4 is a pulse generation circuit, and 5 is a timer. It is a circuit. Agent Patent Attorney Ishi 1) Chief Figures 2, 1 and 3 Procedural Amendments (Voluntary) 1 October 26, 1985 Mr. Commissioner of the Japan Patent Office ('1, Indication of Case Wi Japanese 2000 Patent ii fls 164356 No. 2,
Name of the invention Accumulation time measuring device 3, relationship with the case of the person making the amendment Patent applicant address 1048 Kadoma, Kadoma City, Osaka Prefecture Name (58
3) Matsushita Electric Works Co., Ltd. Representative: Sada Fujii 4, Agent postal code: 530 5, Date of amendment order: 6, Invention σ2 increase due to amendment: None 7, Subject of amendment) In the drawings attached to the specification of the present application , Figure 3 is corrected as shown in the attached sheet.

Claims (1)

[Claims] (1) A current detection resistor connected between the test terminal and the measurement terminal connected to the smoke sensitivity test device, a differential amplifier circuit that differentially amplifies the terminal voltage of the current detection resistor, and the differential amplification circuit. A pulse generating circuit comprising two comparison circuits receiving output voltages of the circuits, the comparison circuits operating at different comparison levels, and generating pulses of a constant width by the output of the comparison circuit having a lower comparison level. , and a timer circuit that starts timing with the output of the pulse generation circuit, and the timer circuit finishes timing and measures time with the output of the comparison circuit having a high comparison level. Time measuring device.