CN2253890Y - Holding tester having transient control circuit - Google Patents

Abstract

The utility model provides a holding tester having a transient control circuit, which comprises a first RC network, a second RC network, a first transistor switch, a second transistor switch, and a limit circuit. The utility model is used for preventing the false triggering of a holding tester when a lamp is extinguished or when other loads are deexcited. The utility model adopts few circuit elements with low cost and avoids the need of special time sequence chips or other complex circuits.

Description

The occupancy detector that contains transient control circuit

The utility model relates to the occupancy detector that contains transient control circuit, and more particularly, relates to detect because the occupancy detector that the vacation that transient signal causes triggers.

Occupancy detector is the device that is used in automatic optical switch and the safety system, is used for lighting lamp or activating other forms of Alarm Display when people or vehicle enter the monitored area.This device is used together with outdoor lighting lamp, for example, lights the passageway when the people goes to the Qianmen, or opens when automobile and to illuminate motorway when near.They are also referred to as detecting intrusion, particularly in security personnel use.

A kind of occupancy detector of common form is passive infrared (PIR) motion detector.This PIR motion detector is used for the people or other hot object enters or during near the visual field of detector, detects the heat of the infrared radiation form of distributing from people or object.When this motion detector detected the suitable thermal pulse characteristic of moving heat sources, it provided a signal of telecommunication with exciting light or other sirens.For electroluminescence, motion detector makes luminous maintenance predetermined time duration usually after detecting motion.Therefore, for example when a people entered the visual field of motion detector, a lamp was lighted, and kept luminous according to user's selection and in the time that is generally 5,10 or 15 minutes.Subsequently, when preset time finished, light extinguished automatically, unless detected further motion.

Yet, when light extinguishes, produced a problem.When lamp extinguished, the unexpected decline of the electric current by lamp can produce extra transient state electrical noise signal in other parts of motion detector circuit.These transient noise signals trigger motion detector sometimes, thereby make lamp luminous again.The infrared radiation that produces when lamp extinguishes also can make infrared radiation be subjected to triggering again.Usually, lamp needs some time to cool off after extinguishing.When lamp cooled off in certain temperature range, the ratio of the infrared radiation that they distribute increased, and this infrared radiation, according to the environment around it, possible passive movement detector directly or by reflection detects.And motion detector can be interpreted as this transient state infrared signal the incident of occupying this moment, thereby lamp is triggered again.

In order to address these problems, the motion detector in past has comprised sequence circuit, time of several seconds so that motion detector is under an embargo after lamp extinguishes.In this time of several seconds, lamp extinguishes fully and cools off, and extra noise signal disappears.Motion detector recovers scanning subsequently, to detect further motion.

In the past, motion detector has comprised special-purpose integrated circuit timing chip or other complicated circuit, temporarily to forbid motion detector or otherwise overcome false triggering problem when lamp extinguishes.For PIR motion detector cheaply, the extra cost of sequential and inhibit circuit is significant, and has increased the price of the motion detector that offers the user.

The utility model provides the occupancy detector that comprises a kind of control circuit, this occupancy detector can prevent that the vacation of when lamp extinguishes (when perhaps other load is de-energized when some) from triggering, it has adopted less low-cost circuit element, and has avoided the needs to special-purpose sequential chip or other more complicated circuit.

Occupancy detector of the present invention comprises the occupancy detector circuit of the object of the visual field that is used for checkout gear.This occupancy detector circuit provides the M signal of the detection of expression object.An output stage receives this M signal, and responds it and a triggering signal that is used for exciter or other loads is provided.One has the feature charging RC network of die-away time, is coupled with this output stage, thereby makes this feature charging can control the duration that output stage is confirmed triggering signal die-away time.That is, the duration that lamp or other loads are encouraged has been controlled in the charging of this feature die-away time.The vacation of occupancy detector triggered when in brief, the utility model had adopted following method to prevent that lamp from extinguishing.From the output signal of occupancy detector circuit, promptly M signal and any triggering signal that may occur by a first transistor switch, and are added on the above-mentioned RC network.Be provided with one and have its oneself feature charging second RC network of die-away time, and this triggering signal is added on this second RC network.When output stage was removed affirmation to triggering signal (thereby remove lamp or other loads excitation), second RC network was discharged by a transistor seconds switch, so that the transistor seconds switch is placed its conducting state.This transistor seconds switch is used to cut off the first transistor switch subsequently in the feature of second RC network is charged die-away time.During this period, first RC network is blocked, thereby can not receive the output of occupancy detector circuit, and this output is then passed through on a return path by the transistor seconds switch.

A kind of occupancy detector of the present utility model comprises: have first RC network that one first feature is charged die-away time, described first RC network and the coupling of described output stage, thereby make the charging of described first feature can control the duration that described output stage is confirmed described triggering signal die-away time, thereby and control the duration that described load is encouraged; Has second feature charging second RC network of die-away time, described second RC network and described output stage are coupled, when described output stage is confirmed described triggering signal, charging, and when removing affirmation to described triggering signal, described output stage discharges; The first transistor switch is used to apply described M signal so that described first RC network is charged; The return path that limits described M signal is to carry out the circuit arrangement of bypass to described output stage; The transistor seconds switch, it is disengaged in described triggering signal and moves when confirming by described second feature charging definite duration of die-away time, is used to turn-off described the first transistor switch and cuts described return path; Thereby when the operation of described transistor seconds switch, be disengaged all transient states and other signals received when confirming in described triggering signal, all be divided to described return path.

Another kind of occupancy detector of the present utility model comprises: have first RC network that one first feature is charged die-away time, described first RC network and the coupling of described output stage, thereby make the charging of described first feature can control the duration that described output stage is confirmed described triggering signal die-away time, thereby and control the duration that described load is encouraged; The first transistor, it has first emitter, first collector electrode and first base stage, and obtains suitable connection receiving described M signal at described first collector electrode and described first base stage, and is connected to described first RC network at described first emitter; First resistor network that links to each other with described first base stage, thus make described first base stage receive the described M signal of the current potential that is lower than described first collector electrode; Transistor seconds, it has second emitter, second collector electrode and second base stage, described second collector electrode obtains suitable connection so that described first base stage is setovered, and further is in series with described first resistor network, and described second emitter is connected to the output of described output stage; Has second feature charging second RC network of die-away time, described second RC network comprises a capacitor and obtains suitable connection to discharge by described second base stage that described capacitor obtains suitable connection to obtain charging when described triggering signal is subjected to confirming; And a diode, it is connected between the public output of described second RC network and described output stage and described second emitter, and this diode is subjected to reverse bias when described second RC network is discharged; Thereby described second RC network is charged when described triggering signal is subjected to confirming and discharge when described triggering signal is disengaged affirmation, second RC network of described discharge is setovered cutting off described the first transistor in described second feature charging duration of die-away time to described transistor seconds, and all obtains shunting by described first resistor network from all signals of described occupancy detector circuit during this period.

A specific embodiment implementing above-mentioned design is described below.According to this embodiment, can utilize two transistors that are used for these two transistor switches, two capacitors, at least one diode and the several resistance that is used for these two RC network to implement, this has all reduced many than the number and the complexity that are used to provide the parts that prevent the false available technology adopting that triggers.

By following description and accompanying drawing to illustrated embodiment, those skilled in the art will have sufficient understanding to other aspects of the present utility model, advantage and novel feature.

Fig. 1 is a schematic diagram, has shown according to control circuit of the present utility model.

Fig. 1 has shown an occupancy detector circuit with the form of block diagram and illustrative circuitry.The occupancy detector circuit of representing with piece 10 integral body detects the appearance of the target object in the visual field of device, and provides expression to detect a M signal that occupies incident on output line 11.An occupancy detector generally includes an output stage, and this output stage receives this M signal and responds it and a triggering signal is provided, to trigger lamp or other loads.In Fig. 1, output stage is provided by amplifier 12; And amplifier 12 in response to the M signal on the line 11, provides a high signal at its output.Triggering signal at the output of amplifier 12 be added to commutation circuit 13, and the latter is added to line voltage distribution on the lamp 14, with exciter.

At this, the character of problem to be solved in the utility model will be considered in more detail.Occupancy detector circuit 10 generally includes one or more detector, and these detectors detect the existence of target object.For example, these detectors can detect the infrared radiation of launching from target (for example the PIR motion detector), perhaps detect sound level or other expressions amount to the intrusion in the zone of occupancy detector monitoring.Incident has taken place to occupy with check independently in this occupancy detector circuit even can comprise some different detectors.Piece 10 also generally includes the signal processing circuit of the primary signal that is used to handle self-detector.The characteristic of expection desirable target picked up signal from the institute monitored area is distinguished or differentiated to this signal processing circuit.For example, a common PIR motion detection circuit has adopted threshold value to differentiate the incident of occupying.This circuit when the heat from target object shines on the PIR detector, is sought the individual pulse that is produced, and subsequently by only the pulse with minimum threshold size being responded, seeks to differentiate unwanted signal.In this way, this circuit region is told the pulse that weak incident infrared radiation produces, and this infrared radiation unlikely be from the mankind or vehicle.In a word, when the occupancy detector circuit is judged when having received appropriate signals, it provides an output signal on online 11, and incident has taken place to occupy in expression.Adopt the occupancy detector circuit of this threshold value authentication technique, the general easier influence that is subjected to false triggering noise problem to be solved in the utility model, because the unexpected decline of line current when lamp extinguishes can produce the noise spike that surpasses threshold level in threshold circuit.

In Fig. 1, be used to overcome the circuit of this false triggering problem, be set between occupancy detector circuit 10 and the commutation circuit 13.One first electric capacity 16 and amplifier 12+input 17 links to each other; Reference voltage is added to-input 18 on.Electric capacity 16 has the discharge path by resistor network 19, and resistor network 19 comprises the fixed resistance 21 of connecting with variable resistor 22 in the embodiment in figure 1.Electric capacity 16 and resistor network 19 have formed first RC network, it have the time constant control that is subjected to this RC network, its own feature charges die-away time.Chong Dian electric capacity 16 fully, general+input 17 remain on the current potential greater than the reference potential the on-input 18, and amplifier 12 provides high output signal.As long as the electric charge on the electric capacity 16 makes input 17 be higher than input 18, amplifier 12 just continues to provide high output signal.The discharge rate of electric capacity 16 is determining amplifier 12 that the duration of high output is provided. Resistor network 16 and 19 feature charging die-away time, can be adjusted by regulating variable resistor 22.

One first switching transistor 23 is set between electric capacity 16 and the output line 11.Transistor 23 and output line 11 are linking to each other on 27 at two paths 26.Path 26 is connected to the conducting side of transistor 23 with output line 11, promptly be connected to the collector electrode of npn transistor 23 shown in Figure 1, and path 27 is added to suitable current potential the base stage of transistor 23 by resistance 28.One second capacitor 31 by diode 32, and is connected between the output and ground of amplifier 12, thereby the output signal from amplifier 12 is added on commutation circuit 13 and the capacitor 31.Second switch transistor 33 is coupled to second path 27 from output line 11 with capacitor 31.

In operation, when having occurred on online 11 representing to occupy the pulse of incident, this pulse is added on path 26 and 27.Pulse on path 27 makes transistor 23 conductings, and the pulse on path 26 is charged to electric capacity 16 by transistor 23.This with amplifier 12+voltage at input 17 places, bring up to and be higher than-level of the reference voltage at input 18 places.Amplifier 12 provides a high output subsequently, and the latter encourages 13 pairs of lamps 14 of commutation circuit.Height output from amplifier 12 also makes capacitor 31 charge by diode 32.Simultaneously, electric capacity 16 discharges by resistor network 19.

When lamp 14 extinguished (generally be detecting the last incident that occupies after certain interval, this is determined by the feature charging of resistor network 16,19 at interval die-away time), the output of amplifier 12 descends, this makes 13 pairs of lamps 14 of commutation circuit forbid.Capacitor 31 is subjected to the prevention of diode 32, thereby discharges by the base stage of transistor 33 by the discharge of amplifier 12.In this stage, transistor 33 conductings.A dummy output on that produce in the occupancy detector circuit when lamp 14 extinguishes, online 11 will be shunted by transistor 33 along return path 27 and 27 ', rather than be charged by 23 pairs of electric capacity 16 of transistor.Therefore, false trigger impulse will can not produce high impulse at the output of amplifier 12.Introduced diode 34, leaked and electric capacity 16 is charged from the base current of transistor 33 preventing.Diode 35 adds a voltage drop on path 26, be added in voltage drop on the path 27,27 ' with balance diode 34.Capacitor 31 and resistance 36 have formed one second RC network, and it has the feature charging die-away time of oneself, and this feature charging has been controlled the duration of transistor 33 conductings die-away time, thereby has controlled the duration that prevents that electric capacity 16 is charged.When capacitor 31 discharges into predetermined level when following, transistor 33 turn-offs and gets clogged from the return path of output line 11.Come this moment all transient processes of lamp 14 of self-gravitation all over and done with, and will allow M signal turn-on transistor 23 new on the output line 11 and the aforesaid high signal of generation on the output of amplifier 12.

The utility model compared with prior art a remarkable advantage, it is the reduction significantly of cost, this is owing to having adopted the circuit as among the embodiment of Fig. 1 to realize, this circuit has only two transistors 23 and 33, two electric capacity 16 and 31, resistance 21,22,28 and 36, though and at least one diode 32- diode 34 and 35 be that to carry out more stable operation institute desirable.This has been avoided higher integrated circuit (IC) chip of cost and relevant, suitably the setover needs of required independent circuit block normally.The concrete component value of various resistance, electric capacity, transistor and miscellaneous part shown in Figure 1 depends on concrete application and operating environment.Under the situation of given foregoing circuit scheme and description, the determining of suitable component value, be those skilled in the art can carry out, thereby be described no longer here.

Above description and accompanying drawing have been announced embodiment of the present utility model.By means of the disclosure, those skilled in the art can be understood that, can adopt various corrections, replacement structure and equivalent to realize advantage of the present utility model.For example, those skilled in the art will recognize, and can adopt other transistor arrangements of the switching function that provides of equal value.In addition, though being the npn transistor and having adopted in this manual and be suitable for the transistorized term of npn here, but this circuit equally also can adopt pnp transistor and field-effect transistor to implement, as those skilled in the art easily understand.Therefore, the utility model is not limited only to foregoing description and explanation, but is limited by appending claims.

Claims (5)

1. one kind contains control circuit and is used to prevent the false occupancy detector that triggers, it provides and has shown the M signal of the detection of target object and comprise that one receives described M signal and responds it and a triggering signal output stage is provided, be used in response to the detection of described target object and a load is encouraged, it is characterized in that: described occupancy detector comprises

Has first RC network that one first feature is charged die-away time, described first RC network and the coupling of described output stage, thereby make the charging of described first feature can control the duration that described output stage is confirmed described triggering signal die-away time, thereby and control the duration that described load is encouraged;

Has second feature charging second RC network of die-away time, described second RC network and described output stage are coupled, when described output stage is confirmed described triggering signal, charging, and when removing affirmation to described triggering signal, described output stage discharges;

The first transistor switch is used to apply described M signal so that described first RC network is charged;

The return path that limits described M signal is to carry out the circuit arrangement of bypass to described output stage;

The transistor seconds switch, it is disengaged in described triggering signal and moves when confirming by described second feature charging definite duration of die-away time, is used to turn-off described the first transistor switch and cuts described return path;

Thereby when the operation of described transistor seconds switch, be disengaged all transient states and other signals received when confirming in described triggering signal, all be divided to described return path.

2. according to the occupancy detector of claim 1, it is characterized in that described first and second transistor switches comprise first and second transistors respectively,

Described transistor seconds is suitably connected, when confirming described the first transistor cut off by the described second feature charging determined duration of die-away time to be disengaged in described triggering signal, and

Described the first transistor obtains suitable connection, when it is not cut off by described transistor seconds described M signal is added to described first RC network.

3. according to the occupancy detector of claim 2, it is characterized in that

Described the first transistor has one first emitter, first collector electrode and one first base stage, described the first transistor obtains suitable connection, to receive described M signal at described first collector electrode and in described first base stage, and link to each other with described first RC network, and be subjected to suitable biasing when described transistor seconds switch is not worked, not make described M signal by described first RC network at described first emitter; And

Described transistor seconds has second emitter, second collector electrode and second base stage, described transistor seconds obtains suitable connection to receive described M signal at described second collector electrode, and be connected to described first base stage of described the first transistor, and be subjected to the suitable biasing of described second RC network and in the duration that described second feature charging is determined die-away time, described M signal be connected to ground in described second base stage at described second collector electrode.

4. according to the occupancy detector of claim 1, it is characterized in that described second RC network comprises a capacitor and a diode, described capacitor is connected to described output stage by described diode, when described triggering signal is identified, to charge, described capacitor further obtains suitable connection, discharges so that described transistor seconds switch is carried out forward bias by described transistor seconds switch when confirming to be disengaged when described triggering signal.

5. one kind comprises the occupancy detector that prevents the false circuit that triggers, provide to show the M signal of the detection of target object and comprise that an output stage-this output stage receives described M signal and responds it and provide a triggering signal with in response to the detection of described target object and a load is encouraged, it is characterized in that: described occupancy detector comprises

Has first RC network that one first feature is charged die-away time, described first RC network and the coupling of described output stage, thereby make the charging of described first feature can control the duration that described output stage is confirmed described triggering signal die-away time, thereby and control the duration that described load is encouraged;

The first transistor, it has first emitter, first collector electrode and first base stage, and obtains suitable connection receiving described M signal at described first collector electrode and described first base stage, and is connected to described first RC network at described first emitter;

First resistor network that links to each other with described first base stage, thus make described first base stage receive the described M signal of the current potential that is lower than described first collector electrode;

Transistor seconds, it has second emitter, second collector electrode and second base stage, described second collector electrode obtains suitable connection so that described first base stage is setovered, and further is in series with described first resistor network, and described second emitter is connected to the output of described output stage;

Has second feature charging second RC network of die-away time, described second RC network comprises a capacitor and obtains suitable connection to discharge by described second base stage that described capacitor obtains suitable connection to obtain charging when described triggering signal is subjected to confirming; And

A diode, it is connected between the public output of described second RC network and described output stage and described second emitter, and this diode is subjected to reverse bias when described second RC network is discharged;

Thereby described second RC network is charged when described triggering signal is subjected to confirming and discharge when described triggering signal is disengaged affirmation, second RC network of described discharge is setovered cutting off described the first transistor in described second feature charging duration of die-away time to described transistor seconds, and all obtains shunting by described first resistor network from all signals of described occupancy detector circuit during this period.

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