DE2159760B2 - ELECTRONIC THRESHOLD SWITCH - Google Patents
ELECTRONIC THRESHOLD SWITCHInfo
- Publication number
- DE2159760B2 DE2159760B2 DE19712159760 DE2159760A DE2159760B2 DE 2159760 B2 DE2159760 B2 DE 2159760B2 DE 19712159760 DE19712159760 DE 19712159760 DE 2159760 A DE2159760 A DE 2159760A DE 2159760 B2 DE2159760 B2 DE 2159760B2
- Authority
- DE
- Germany
- Prior art keywords
- semiconductor light
- threshold switch
- emitting diode
- transistor
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
- H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
- H03K3/26—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback
- H03K3/28—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback
- H03K3/281—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator
- H03K3/286—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of bipolar transistors with internal or external positive feedback using means other than a transformer for feedback using at least two transistors so coupled that the input of one is derived from the output of another, e.g. multivibrator bistable
- H03K3/2893—Bistables with hysteresis, e.g. Schmitt trigger
- H03K3/2897—Bistables with hysteresis, e.g. Schmitt trigger with an input circuit of differential configuration
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
- H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
- H03K3/027—Generators characterised by the type of circuit or by the means used for producing pulses by the use of logic circuits, with internal or external positive feedback
- H03K3/037—Bistable circuits
- H03K3/0377—Bistables with hysteresis, e.g. Schmitt trigger
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
- H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
- H03K3/42—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of opto-electronic devices, i.e. light-emitting and photoelectric devices electrically- or optically-coupled
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Electronic Switches (AREA)
- Measurement Of Current Or Voltage (AREA)
- Led Devices (AREA)
Description
Für viele Anwendungen, z. B. zur Kontrolle der Batteriespannung in Kameras, Tonbandgeräten, tragbaren Rundfunk- und Fernsehgeräten etc. werden Schwellwertschalter benötigt, bei denen das Leuchten eines lichtemittierenden Bauelements (Glühlampe oder Leuchtdiode), das Überschreiten einer vorgegebenen Schwelle anzeigt.For many applications, e.g. B. to control the battery voltage in cameras, tape recorders, portable Radio and television sets, etc., threshold switches are required in which the lights of a light-emitting component (incandescent lamp or light-emitting diode), the crossing of a indicated threshold.
Die Fig. 1 der Zeichnung zeigt ein hierzu geeignetes und bekanntes Schaltungsprinzip. Der Schwellwertschalter 1 weist die beiden Eingänge A und B auf, die beispielsweise die Eingänge ei.ies Differenzverstärkers sein können, von denen der Eingang B an die von der Z-Diode D gebildete Referenzspannungsquelle angeschlossen ist, während dem Eingang A eine der zu überwachenden Spannung proportionale Steuerspannung zugeführt wird. Überschreitet die Steuerspannung die Referenzspannung, so leuchtet die Glühlampe L auf. Anstelle der Glühlampe kann auch eine Halbleiter-Leuchtdiode verwendet werden.Fig. 1 of the drawing shows a suitable and known circuit principle. The threshold switch 1 has the two inputs A and B , which can, for example, be the inputs of a differential amplifier, of which the input B is connected to the reference voltage source formed by the Zener diode D , while the input A is one of the voltage to be monitored proportional control voltage is supplied. If the control voltage exceeds the reference voltage, the light bulb L lights up. A semiconductor light-emitting diode can also be used instead of the incandescent lamp.
Die Erfindung betrifft somit einen elektronischen Schwellwertschalter mit Anzeige des Schaltzustandes durch Halbleiter-Leuchtdioden und mit einer den Schwellwert bestimmenden Referenzspannungsquelle.The invention thus relates to an electronic threshold switch with a display of the switching state by means of semiconductor light-emitting diodes and with a reference voltage source that determines the threshold value.
Bei niedrigen Batteriespannungen unter 6 V und bei dem derzeit allgemein üblichen und erstrebten Aufbau als integrierte Halbleiterschaltung besteht das Problem, daß kein geeignetes Referenzbauelement mit ausreichend geringem Temperaturkoeffizienten für den Schwellwertschalter zur Verfügung steht. Die Erfindung löst dieses Problem und beseitigt die geschilderten Nachteile dadurch, daß die an der zur Anzeige dienenden Halbleiter-Leuchtdiode in Flußrichtung abfallende Spannung als Referenzspannung dien!.. Hierbei ist es vorteilhaft, die Halbleiter-Leuchtdiode über einen Vorwiderstand am spannungsführenden Pol der Versorgungsspannungsquellc anzuschließen.At low battery voltages below 6 V and at the currently common and desirable Construction as an integrated semiconductor circuit has the problem that no suitable reference component with a sufficiently low temperature coefficient for the threshold switch stands. The invention solves this problem and eliminates the disadvantages outlined in that the on the semiconductor light-emitting diode used for display purposes, the voltage dropping in the flow direction as the reference voltage dien! .. Here it is advantageous to connect the semiconductor light-emitting diode to the to connect the live pole of the supply voltage source.
In F i g. 2 ist die erfindungsgcmäße Lösung gezeigt. Dort ist der Eingang B des Schwellwertschalters 1 mit der Anode der Halbleiter-Leuchtdiode LD verbunden, deren Kathode am Schaltungsnullpunkt angeschlossen ist. Damit dient die in Flußrichtung an der Halbleiter-Leuchtdiode LD abfallende Spannung als Referenzspannung.In Fig. 2 shows the solution according to the invention. There the input B of the threshold switch 1 is connected to the anode of the semiconductor light-emitting diode LD , the cathode of which is connected to the circuit zero point. The voltage drop across the semiconductor light-emitting diode LD in the flow direction thus serves as a reference voltage.
In Serie mit der Halbleiter-Leuchtdiode LD kann der Vorwiderstand R geschaltet sein, der in F i g. 2 gestrichelt gezeichnet ist. Hierdurch wird auch in einem Betriebszustand, in dem die Halbleiter-Leuchtdiode LD nicht mit dem zum Leuchten erforderlichen Strom betrieben wird, ein zum Entstehenlassen der als Referenzspannung dienenden Flußspannung geeigneter Vorstrom durch die Diode geführt. Selbstverständlich ist es auch möglich, den Vorwiderstand R durch eine Stromquelle oder ein geeignetes Bauelement des Schwellwertschalters 1 zu ersetzen, das den erwähnten Vorstrom liefert. The series resistor R can be connected in series with the semiconductor light-emitting diode LD , which is shown in FIG. 2 is drawn in dashed lines. As a result, even in an operating state in which the semiconductor light-emitting diode LD is not operated with the current required for lighting, a bias current suitable for creating the forward voltage serving as reference voltage is passed through the diode. Of course, it is also possible to replace the series resistor R with a current source or a suitable component of the threshold switch 1 which supplies the mentioned bias current.
Die F ig. 3 zeigt eine zur monolithischen Integrierung geeignete Schaltungsanordnung eines Schwellwertschalters, der, wie aus der Figur ersichtlich, aus einem unsymmetrischen Differenzverstärker besteht,The fig. 3 shows a circuit arrangement of a threshold switch suitable for monolithic integration, which, as can be seen from the figure, consists of an asymmetrical differential amplifier,
wobei der Arbeitswiderstand des einen Differenzverstärkertransistors als geschaltete Stromquelle ausgebildet ist.wherein the load resistance of the one differential amplifier transistor is designed as a switched power source.
Im einzelnen bilden die Transistoren 7"I und 72 die beiden Differenzverstärkertransistoren, deren Emitter über den gemeinsamen Emitterwiderstand R1 mit dem Schaltungsnullpunkt verbunden sind. Dem zweiten Differenzverstärkertransistor 72 ist der Transistor 7 3 nach Art einer Darlington-Stufe vorgeschaltet, um eine geringe Temperaturabhängigkeit zu erhalten und der Halbleiter-Leuchtdiode LD so wenig Steuerstrom wie möglich zu entziehen. Der Kollektor des Differenzverstärkertransistors Tl ist direkt mit dem spannungsführenden Pol τ der Versorgungsspannungsquelle Un verbunden.Specifically, the transistors 7 ″ I and 72 form the two differential amplifier transistors, the emitters of which are connected to the circuit zero point via the common emitter resistor R 1 and to withdraw as little control current as possible from the semiconductor light-emitting diode LD . The collector of the differential amplifier transistor Tl is connected directly to the live pole τ of the supply voltage source U n.
Im Kollektor des Differenzverstärkertransistors 71, dessen Basis mit dem Eingang A identisch ist, ist die aus den zu den Transistoren Tl. Tl, Ti komplementären Transistoren 74 und 7" 5 sowie dem Widerstand R'c bestehende geschaltete Stromquelle angeordnet. Die Basis des Transistors 74 und der Kollektor des Transistors 75 sind gemeinsam am Kollektor des Transistors 71 angeschlossen, während die Basis des Transistors 75 und der Emitter des Transistors 74 gemeinsam über den Widerstand R'c am spannungsführenden Pol -+■ der Versorgungsspannungsquelle Up angeschlossen sind, an dem auch der Emitter des Transistors 75 liegt. Der Kollektor des Transistors 74 ist mit der Basis des Transistors 73, der Anode der Halbleiter-Leuchtdiode LD und mit dem versorgungsspannungsfernen Ende des Vorwiderstands R verbunden, welcher gemeinsame Verbindungspunkt mit dem Eingang Zf des Differenzverstärker identisch ist.In the collector of differential amplifier transistor 71, whose base is identical to the input A is arranged consisting of the complementary to the transistors Tl, Tl, Ti transistors 74 and 7 "5 and the resistor R 'c existing switched current source. The base of transistor 74 and the collector of the transistor 75 are connected together to the collector of the transistor 71, while the base of the transistor 75 and the emitter of the transistor 74 are connected together via the resistor R'c to the voltage-carrying pole - + ■ of the supply voltage source Up , to which the Emitter of transistor 75. The collector of transistor 74 is connected to the base of transistor 73, the anode of the semiconductor light-emitting diode LD and to the end of the series resistor R remote from the supply voltage, which common connection point is identical to the input Zf of the differential amplifier.
Die aus den Transistoren 7 4 und 75 gebildete geschaltete Stromquelle wird vom Kollektorstrom des Transistors 71 derart geschaltet, daß über den Kollektor des Transistors 74 der zum Leuchten erforderliche Strom für die Halbleiter-Leuchtdiode LD fließt. Dieser Strom ist durch den Spannungsabfall am Widerstand /?'„ und die Basis-Emitterspannnung des Transistors 75 vorgegeben, so daß dieser Strom als von der Stromquelle eingespeister Konstanlstrom angesehen werden kann.The switched current source formed from the transistors 7 4 and 75 is from the collector current of the Transistor 71 connected in such a way that across the collector of the transistor 74 the current required for lighting for the semiconductor light-emitting diode LD flows. This current is due to the voltage drop across the resistor /? '"And the base emitter voltage of the transistor 75 predetermined, so that this current as a constant current fed in from the current source can be viewed.
Hierzu 2 Blatt ZeichnungenFor this purpose 2 sheets of drawings
Claims (2)
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19712159760 DE2159760C3 (en) | 1971-12-02 | 1971-12-02 | Electronic threshold switch |
| FR7242562A FR2164195A5 (en) | 1971-12-02 | 1972-11-30 | |
| GB5547372A GB1358610A (en) | 1971-12-02 | 1972-12-01 | Electronic threshold switch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19712159760 DE2159760C3 (en) | 1971-12-02 | 1971-12-02 | Electronic threshold switch |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| DE2159760A1 DE2159760A1 (en) | 1973-06-07 |
| DE2159760B2 true DE2159760B2 (en) | 1976-07-08 |
| DE2159760C3 DE2159760C3 (en) | 1979-11-15 |
Family
ID=5826796
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE19712159760 Expired DE2159760C3 (en) | 1971-12-02 | 1971-12-02 | Electronic threshold switch |
Country Status (3)
| Country | Link |
|---|---|
| DE (1) | DE2159760C3 (en) |
| FR (1) | FR2164195A5 (en) |
| GB (1) | GB1358610A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1344794A (en) * | 1972-07-20 | 1974-01-23 | Itt Creed | Isolation equipment for telegraphic apparatus |
| CH639521B (en) * | 1980-05-28 | Ebauches Electroniques Sa | VOLTAGE LEVEL DETECTOR CIRCUIT. | |
| CA1203290A (en) * | 1982-04-28 | 1986-04-15 | Yoshio Shimizu | Signal comparing circuit |
| CN104820126B (en) * | 2015-05-20 | 2017-12-15 | 中国一冶集团有限公司 | Detection and the method and apparatus for suppressing control loop relay induced voltage failure |
-
1971
- 1971-12-02 DE DE19712159760 patent/DE2159760C3/en not_active Expired
-
1972
- 1972-11-30 FR FR7242562A patent/FR2164195A5/fr not_active Expired
- 1972-12-01 GB GB5547372A patent/GB1358610A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB1358610A (en) | 1974-07-03 |
| DE2159760A1 (en) | 1973-06-07 |
| FR2164195A5 (en) | 1973-07-27 |
| DE2159760C3 (en) | 1979-11-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| BF | Willingness to grant licences | ||
| C3 | Grant after two publication steps (3rd publication) | ||
| EHJ | Ceased/non-payment of the annual fee |