JP2011249212A - Relay drive circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relay drive circuit capable of greatly reducing current consumption according to a usage method by accelerating a starting speed without being accompanied with largeness and an increase in cost.SOLUTION: A current/voltage control element is provided, which energizes a drive coil to supply current/voltage that exceeds a rated value of the relay from a rising edge of a drive power supply to the drive coil of the relay for performing opening/closing control of a movable contact, and operates or controls so as to make a return to current/voltage within rating of the relay after the predetermined time elapses. The current/voltage control element is a power supply circuit including a constant current diode, a constant voltage diode and a voltage control function.

Description

  The present invention relates to a relay drive circuit, and more particularly, to a relay drive circuit capable of reducing the rise time of an electromagnetic relay and controlling current consumption.

A mechanical relay circuit that energizes an electromagnetic coil and opens and closes a contact by its magnetic force is used in various situations where a semiconductor switch cannot be substituted. For example, although not limited to this example, a mechanical contact switching system is preferable as a switching means between a transmission / reception circuit and an antenna of a PressTalk wireless transceiver for various reasons, and a relay circuit is usually used. Specifically, a relay circuit is inserted between the radio transceiver and the antenna, and the relay switch is turned on / off each time transmission / reception is repeated, so that either the transmission unit output terminal or the reception unit input terminal In many cases, it is configured to switch and connect antennas.
However, as is well known in electromagnetic relays, when a drive voltage is applied to an electromagnetic coil, the rise of the current flowing through the drive coil is dull due to the effect of the coil inductance, causing a delay in starting the relay. Here, this delay time is referred to as relay activation time or rise time.

Hereinafter, the starting operation will be described using an example of the conventional relay drive circuit shown in FIG.
In FIG. 10, K101 is an electromagnetic relay (hereinafter simply referred to as "relay"), and a voltage is supplied from the power supply voltage line Vcc to one end of a drive coil (included in the relay K101), and the other end of the drive coil is In addition to grounding (grounding) via the relay driver transistor (relay driving transistor) TR101, an ammeter 102 is inserted between the driving coil of the relay K101 and TR101 to measure the operating current and voltage waveform, and voltage observation is performed. Point 103 is set.
Further, the switch SW101 on the right side of FIG. 10 is a movable contact of the relay K101, and is grounded via a resistor R101 in order to measure its starting operation (contact opening / closing), and at the connection point between the SW101 and the resistor R101. A voltage observation point 104 is set.
The state of relay activation will be described with reference to FIG. 11 showing the voltage / current waveforms at the observation points shown in FIG. 10 and the relationship between them.

FIG. 11A shows a signal applied to the base B of the relay drive transistor TR101, which is a transistor drive signal for turning on / off the relay K101. In actual operation of the wireless transceiver, generally the transmission time is relatively short, and most of the time is spent on reception. Therefore, during the transmission while operating (pressing) the press talk switch attached to the microphone or the like. Then, a current is passed through the base B of the relay drive transistor TR101 to turn on the transistor switch. In addition, the relay drive system includes a single stable relay that allows current to flow continuously when the relay is on and a latching relay that energizes when the relay is turned on and off. The case of relay will be described.
When a “high” voltage signal is applied to the base of the relay drive transistor TR101 (NPN transistor) and a base current flows from the base B to the emitter E, the transistor is turned on (conductive), as shown in FIG. The drive current shown in FIG. 11C flows through the ammeter 102 due to the voltage applied to the drive coil of the relay K101. As described above, when a rectangular wave voltage is applied to the drive coil, the current rise becomes dull due to a transient phenomenon caused by time constants such as inductance and stray capacitance of the drive coil. As a result, as shown in FIG. 11 (d), the relay contact operates with a delay of t time (relay activation time) from the voltage applied to the drive coil. The relay drive time t includes the operation time of the mechanical part.

When a relay drive circuit that generates such an operation delay is used in a wireless transceiver, transmission power may be generated before the transmission power amplifier output end of the transmitter is completely connected to the antenna. There is a risk of burning the amplifier. In addition, since the transmission of radio waves is delayed, there is a case where the beginning of the transmission is lost and the head is cut off, and clear communication may be hindered.
Therefore, conventionally, to avoid such problems, measures to realize a relay drive circuit with a fast start-up include selecting and using a relay with a fast start-up speed, and setting the voltage / current value of the relay to the limit of the rated value. There was a method to use it in the enlarged state. That is, when the relay drive voltage is increased, the rise time is also shortened. Normally, the actual relay drive voltage and current value are used at about 80% of the rated value, but if the voltage value is set to a higher voltage value close to the rated voltage value, the relay activation time can be slightly shortened.

JP-A-61-93530

However, the conventional method of selecting and using a relay that has a fast start-up speed is generally expensive, leading to an increase in the cost of the device. For example, when the transmission power of a radio transmitter is large, a relay with excellent relay contact capacity, withstand voltage characteristics, and high frequency characteristics is required, but it is expensive and there are few applicable types and flexibility in selection. It was severely limited.
In addition, as described above in order to avoid an increase in cost, in the method of setting the relay drive current value to the limit of the rated value, there is a risk of impairing the durability of the relay. The amount of heat generated is also large, and it is necessary to add heat dissipation means. In particular, a relay is known to have a lower holding force due to electromagnetic force in a high temperature state, and it is difficult to say that it is an appropriate method of use because the operation may become unstable.
In Patent Document 1, by inserting a parallel circuit of a capacitor having a required capacity and a resistance element in series with the drive coil of the relay, when the power supply voltage is applied to the drive coil, the capacitor becomes fully charged. It has been proposed that a relay is started by a flowing transient current and the current flowing through the relay drive coil is limited by a resistance element after the capacitor is fully charged. This has the effect of reducing the amount of heat generated by the drive coil by reducing the current value after activation of the relay, but does not contribute to the promotion of activation of the relay.
The present invention has been made to solve such problems of the conventional relay drive circuit. The start speed is increased without increasing the size and cost, and the current consumption is greatly increased depending on the method of use. An object of the present invention is to provide a relay drive circuit that can be reduced to a low level.

In order to solve the above problems, a relay drive circuit according to the present invention includes at least a relay that controls opening and closing of a movable contact by energizing a drive coil, and a drive power supply unit that supplies a voltage to the drive coil of the relay And a current / voltage control means arranged in a route for supplying drive current / voltage to the drive coil from the drive power supply means, wherein the drive power supply means supplies a voltage exceeding the rated value of the relay. The current / voltage control means supplies the first open / close switch element and the current / voltage exceeding the rated value of the relay for the required time from the rising edge of the supplied drive current / voltage to the drive coil of the relay. The power supply is operated or controlled to supply a current / voltage within the relay rating to the relay drive coil after the required time has elapsed. / Wherein the voltage is intended to include control elements.
Here, current / voltage means current and / or voltage, and therefore, objects to be controlled include cases of current value, voltage value, and both.
According to this configuration, since the current / voltage exceeding the rated value for the required time from the rising edge of the supplied driving current / voltage is supplied to the relay, the relay is compared with the case of driving with the rated current / voltage. The startup time is reduced. Moreover, since the drive current / voltage shifts to within the rating after the movable contact of the relay is operated, the current application time exceeding the rated value is instantaneous, and the amount of heat generation is small.

In the relay drive circuit according to the present invention, the current / voltage control means includes a constant current diode.
As a result of various experiments, the applicant of the present invention inserts a constant current diode in series with the relay drive coil and applies a drive voltage exceeding the rated value, and the constant current function functions from the rising edge of the drive current / voltage. However, the constant current diode has been found to be in a through (short-circuit) state without current limiting action, and a current exceeding the rated value of the relay is supplied to the relay, and this phenomenon is further utilized. Therefore, without requiring a complicated control circuit, the relay can be activated instantly by applying a current / voltage exceeding the rated value to the rising edge of the relay driving current / voltage by the action of the constant current diode itself. A circuit that can be used is invented.

The relay drive circuit of the present invention is characterized in that a resistor, a thermistor, or a resistor and thermistor circuit network is connected in parallel to the constant current diode.
According to this configuration, it is possible to compensate for fluctuations in the current value accompanying the temperature rise of the constant current diode.

In the relay drive circuit of the present invention, the current / voltage control means includes a constant voltage diode and a second open / close switch element connected in parallel with the constant voltage diode, and the first and second open / close switch elements. By opening and closing each with a control signal shifted by the required time, a current / voltage exceeding the rated value is supplied from the rising edge of the supplied drive current / voltage to the required time relay. It is configured to supply current.
According to this configuration, it is possible to realize a relay drive circuit that functions in the same way by using a constant voltage diode instead of a constant current diode, so that the degree of freedom in design when implementing the present invention is large. Become.

In the relay drive circuit of the present invention, in the invention using the constant voltage diode described above, the current / voltage control means includes a control end of the first on / off switch element and a control end of the second on / off switch element. A signal delay means necessary for supplying a driving current / voltage exceeding the rated value of the required time relay from the rising edge is inserted therebetween.
According to this configuration, since the relay control signal supplied to the control terminal of the first on / off switch is supplied to the control terminal of the second on / off switch with a set delay time, the first on / off switch, It is possible to drive the on / off switch with a desired delay time.

As described above, according to the present invention, the relay drive power supply means has a function capable of supplying a current / voltage exceeding the rated value of the relay, and when the drive current / voltage is supplied to the relay, the relay drive power supply means is slightly increased from the rising edge. By supplying a current / voltage exceeding the rated value of the relay in time (instantaneous), the relay start-up time is shortened, and the relay drive current / voltage is returned to a value within the rated value after the required time has elapsed. It is.
Therefore, it is possible to provide a relay drive circuit that can speed up the start-up speed without increasing the size and cost and can significantly reduce the current consumption depending on the method of use.
In the embodiment, a constant voltage diode, a constant current diode, or an element that functions in the same manner can obtain a stable relay operation even if the power supply voltage fluctuates. In particular, in an in-vehicle electronic device having a large variation in power supply voltage value, the voltage variation of the battery is large, which is useful for providing a stable operation of the relay.

The circuit diagram which shows an example of the relay drive circuit of this invention. 4A and 4B are diagrams for explaining the operation of the relay drive circuit of the present invention. FIG. 4A is a waveform diagram of a base voltage signal of TR1, FIG. (D) is a figure which shows the opening / closing operation | movement of SW1. The circuit diagram which shows the other example of the relay drive circuit of this invention. The circuit diagram which shows the other example of the relay drive circuit of this invention. The relay drive current / voltage characteristic figure which shows the effect which carried out temperature compensation by this invention. The circuit diagram which shows the other example of the relay drive circuit of this invention. 4A and 4B are diagrams for explaining the operation of the relay drive circuit of the present invention. FIG. 4A is a waveform diagram of a base voltage signal of TR1, FIG. (d) is a diagram showing the operation of TR2, (e) is a voltage waveform diagram across the constant current diode, and (f) is a voltage waveform diagram at observation point 3. The circuit diagram which shows the other example of the relay drive circuit of this invention. The circuit diagram which shows the other example of the relay drive circuit of this invention. The circuit diagram which shows the example of the conventional relay drive circuit. FIGS. 8A and 8B are diagrams for explaining the operation of a conventional relay drive circuit, where FIG. 10A is a waveform diagram of a base voltage signal of TR 101, FIG. (Diameter waveform), (d) The figure which shows the switching operation of SW101 of the relay.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a circuit diagram showing an embodiment of a relay drive circuit according to the present invention.
In Figure 1, K1 is an electromagnetic relay (hereinafter simply referred to as "relay"), supplies one drive voltage from the power supply voltage line V _E at the end of the driving coil (included in the relay K1), the other drive coil The end is grounded (grounded) via a relay driver transistor (relay driving transistor: first opening / closing switch element) TR1, and a constant current diode 1 and a compensation resistor R1 are connected between the driving coil of the relay K1 and TR1. Insert a parallel circuit. Further, an ammeter 2 is inserted for current value / voltage observation, and a voltage observation point 3 is set.
A characteristic point in this configuration is that the power supply voltage V _E is set to a value exceeding the rated value of the relay (in this example, twice the rated voltage Vcc), and the constant current diode is connected to the drive coil. This is the point inserted in series. Commonly speaking, the driving voltage of the relay is set to about 80% to 90% of the rated value. However, in the present invention, for example, it is set to about 1.5 to n times the rated value. Here, n times takes into account the allowable current / voltage value of the relay to be used and the amount of heat generated in the time (Td) during which a current / voltage higher than the rated value is energized at the time of start-up based on the present invention. Set as appropriate. That is, if the maximum allowable current / voltage is a relay, the n-fold value can be set large, so that the startup shortening effect can be obtained.

Note that the switch SW1 on the right side of FIG. 1 is a movable contact of the relay K1, and a resistor R2 and a voltage observation point 4 are provided between the power supply voltage line to measure the starting operation (opening / closing of the contact). In the actual circuit, the movable contact of the relay is used as a contact of another circuit depending on the purpose. The circuit configuration shown in FIG. 1 is for explaining the operating principle of the present invention, and it is needless to say that the ammeter 2, voltage observation points 3, 4 and the like are not necessary in an actual relay circuit. Absent.
FIG. 1 shows the voltage waveform at each observation point for easy understanding, so that the effect of the present invention can be understood by comparing with the conventional relay circuit explanatory diagram of FIG. The operation of the relay drive circuit of FIG. 1 will be described with reference to FIG.

FIG. 2A shows a driving signal applied to the base B of the relay driving transistor TR1, which is a transistor driving signal for turning on / off the relay K1, and shows a rising edge portion in an enlarged manner. In this example, an NPN transistor is used. However, the present invention is not limited to this, and a PNP transistor, an FET, or the like may be used. When used in an actual radio transceiver, for example, the voltage applied to the base B of the relay drive transistor TR1 is “high” while operating (pressing) a press talk switch added to a microphone or the like. It would be common to use the transistor switch at the level to turn it on.
As described above, when the power supply voltage V _E (V _E = 2Vcc) exceeding the rated value is applied to the relay driving coil and the transistor TR1 is turned on (closed), a current flows through the driving coil of the relay K1. Since the constant current diode 1 is inserted in the current route, a current as shown in FIG. That is, when a pulsed voltage waveform is applied to the constant current diode 1, the rising edge portion instantaneously becomes conductive (at that time, the voltage at both ends becomes small), and then the current gradually decreases and the required time ( After t), a steady state voltage (Vcc) at which a predetermined current value corresponding to the characteristic (constant current characteristic) of the constant current diode 1 flows is obtained.

An example of the use of a constant current diode is generally one connected in series to an LED for the purpose of supplying a constant current to a light emitting diode (LED), but the present applicant has repeated various experiments as already described. As a result, such a phenomenon of the constant current diode 1 was found and used for the relay drive circuit. The reason why such a phenomenon occurs is that the time constant (function of LCR) that combines the inductance (L) of the drive coil, the capacitance (capacitance) of the diode and other stray capacitances, and the resistance (R) of the drive coil, etc. Furthermore, it is considered to be due to the junction characteristics of the diode.
When a constant current diode 1 is inserted in series with the relay and a drive power supply exceeding the rated voltage is supplied, a value exceeding the rated voltage is instantaneously exceeded at the rising edge of the relay drive power supply, for example, 1.5 to 3 times the rated voltage. Since the voltage is applied, the relay activation time t (rise time) is greatly shortened. As a result of various experiments, the applicant of the present application has confirmed that it is shortened by about 20% to 50% compared to the case of driving at the rated voltage (about 80% of the rated value).

FIG. 2 (c) shows the drive current waveform flowing through the ammeter 2. As a result, as shown in FIG. 2 (d), the rise time of the movable contact (SW1) of the relay K1 is shortened. It is possible to operate an inexpensive relay with a high-speed operation that exceeds the catalog specification. Although there is a possibility that an irregular current (not shown) is instantaneously generated at the rising edge portion in FIG. 2 (c), there is no problem even if it is ignored in an actual circuit.
As described above, according to the present invention, the driving current is returned to the normal rated value after instantaneously flowing a large current at the time of relay driving to shorten the start-up time, so that driving without increasing current or increasing cost is possible. Rapid start-up control is possible even for relays with small current / voltage ratings.
It is known that the drive current value in the steady state after starting once does not necessarily need to be about 80% of the rated value, and the contact adsorption state can be maintained even with about 30% to 50%. Further, it will be possible to obtain a further power saving effect by setting the necessary minimum holding current according to the rating (value notified from the manufacturer) of each relay.
A resistor R1 connected in parallel to the constant current diode 1 of FIG. 1 is a temperature compensating resistor. That is, the constant current (pinch-off current) value of the constant current diode 1 decreases in a high temperature state, resulting in a decrease in the driving force of the relay. Therefore, the shunt current is energized so that the necessary driving force can be obtained even at the assumed maximum temperature. The resistance value is appropriately set according to the characteristics of the relay and the constant voltage diode 1 to be used.

FIG. 3 is a relay drive circuit showing a modified embodiment of the present invention. In this example, in order to correct the change in the constant current value due to the temperature rise of the constant current diode 1 described above, a temperature compensation resistor connected in parallel to the constant current diode 1 in FIG. 2 is used as a thermistor (thermo sensitive register). It is a replacement. As is well known, a thermistor is a temperature-sensing semiconductor element in which an electrode is attached to a ceramic piece mainly composed of manganese, nickel, etc., and the electrical resistance decreases as the temperature rises (positive (PTC) / negative (NTC)). It is a resistance element having a temperature coefficient.
In the example shown in FIG. 3, the constant current diode 1 is connected in parallel with an NTC thermistor 5 having a negative temperature coefficient, and the resistance value is decreased as the temperature rises, and the current to be shunted is increased. This compensates (compensates) a decrease in current flowing through the current diode 1. The temperature coefficient of the thermistor may be appropriately selected according to the relay to be used, the characteristics of the constant current diode 1, the assumed temperature range, and the like.

Further, FIG. 4 is a circuit diagram showing an example of variations of temperature compensation. By using a thermistor, it is possible to compensate for the current decrease due to the temperature increase of the constant current diode 1, but if the temperature becomes even higher (high temperature) or the power supply voltage becomes abnormally high, a large current will be generated. There is a possibility that the thermistor flow and further the resistance value of the thermistor decreases and the self-heating value increases.
Therefore, as the thermistor 6, a plurality of thermistors are connected in series and parallel to form a thermistor circuit network, and the current amount per thermistor is dispersed and reduced to avoid a thermal runaway state. In addition, a short circuit condition is prevented by inserting a resistor R3 in series with the thermistor network.
Thus, in the present invention, since a value exceeding the rated value is set as the power supply voltage, it is useful in terms of safety design to have means for preventing an excessive current from flowing through the relay.

FIG. 5 is a diagram showing an example in which a rise in relay current / voltage accompanying a temperature rise is compensated by a thermistor and a resistor network.
In addition, it is possible to correct | amend the conduction | electrical_connection current of the constant voltage diode 1 more precisely with respect to a temperature change by using a network with a several thermistor and resistance. Further, the present invention is not limited to this example, and various configurations such as connecting a resistor having a desired value in parallel to the thermistor are possible.
In the above embodiment, a case where a constant current diode is connected in series to the relay drive coil and a drive current / voltage that is equal to or higher than the rated voltage is instantaneously applied to perform high-speed operation that exceeds the specification, In the present invention, the same effect can be obtained by a circuit in which a constant voltage diode and a second switching element are combined instead of the constant current diode.

FIG. 6 shows another example of the relay drive circuit of the present invention. The same circuit components as those already described are denoted by the same reference numerals, and redundant explanations are omitted. This example is different from what has already been described in that a constant voltage diode 7 is connected between the drive coil of the relay K1 and the collector C of the relay driver transistor (relay drive transistor) TR1, which is the first switching element. This is the point where a circuit connected in parallel to the collector C and the emitter E of the transistor switch TR2 which is an open / close element is inserted.
As is well known, a constant voltage diode is called a Zener diode. When a voltage is applied in the opposite direction, a Zener breakdown (avalanche breakdown) occurs at a certain voltage value, and it is constant regardless of the value of the flowing current. Is often used as a voltage reference. When the constant voltage diode having such characteristics is combined with the second switching element as shown in the figure, the constant voltage diode is bypassed (short-circuited) when the switching element is in the closed state, and is fixed only when the switching element is in the open state. The voltage diode will function. In this example, the power supply voltage is set to 24 V, and a Zener voltage (V _Z ) of 12 V, which is half the power supply voltage (V _E ), is selected.
That is, the Zener voltage (V _Z ) = the power supply voltage (V _E ) −the rated voltage (Vcc) of the relay. By setting the control signal delayed in the required time to the base B of the first switch element TR1 and the second switch element TR2 as shown in the figure, the relay drive voltage corresponds to the delay time as shown in the figure. A voltage exceeding the rating (V _E ) is applied only for a period, and after the delay time has elapsed, the voltage is reduced by a Zener voltage (V _Z ) by a constant voltage diode, and the relay is driven by a voltage within the rated value.

FIG. 7 is a signal waveform diagram for explaining the operation of the circuit shown in FIG. FIG. 7A shows a relay drive signal voltage (control signal) applied to the base B of the first opening / closing element TR1, and as shown in FIG. TR1 becomes conductive (closed) and is in a state where current can flow through the relay drive coil. FIG. 7C shows a signal waveform applied to the base B of the second switch element TR2, and this signal delays the signal applied to the base of the first switch element TR1 by a required time (Td). In addition, there is a relationship in which “high” and “low” are reversed. With this signal, the second opening / closing element TR2 performs a short circuit (closed) and an open (open) operation as shown in FIG. When the second switching element TR2 operates as shown in the figure, the voltage across the constant voltage diode 7 becomes as shown in FIG. 7 (e).
That is, the voltage across the constant voltage diode 7 becomes a Zener voltage (12 V in this example) while the first switch element TR1 is in a short circuit (contact) state and the second switch element TR2 is open. .

Further, the first switching element TR1 is a short circuit (contact) state, and, in the second switching element TR2 is short (closed) state, the direct source voltage V _E is applied to the relay drive coil, the The timing is when the voltage observation point 3 (cold side voltage of the relay drive coil) shown in FIG. Therefore, as apparent from comparison between FIGS. 7A and 7F, the base signal waveform of the first switching element TR1 directly exceeds the power supply voltage V _E (constant values) in the delay time Td from the rising portion. Since the voltage is applied to the relay drive coil, its rise is shortened. Note that the magnitude relationship between the waveform of FIG. 7 (f) and the voltage applied to the relay drive coil is reversed.
As described above, the present invention is not limited to a constant current diode, and can also be realized by using a constant voltage diode. Since the constant voltage diode is used as a reference potential, there are many types and the degree of freedom in design is high, which is convenient for realizing the present invention. If the constant current diode of FIG. 1 described above is replaced with a constant voltage diode, if there is one that exhibits the same transient phenomenon as the constant current diode and can perform relay drive promotion operation, connect in parallel. The second open / close switch element would be unnecessary.

FIG. 8 is a modification of the embodiment described with reference to FIGS. 6 and 7 and shows an example in which a circuit for generating a control signal to be supplied to the first and second switching elements is added. .
In this example, the delay circuit 8 and the inverter circuit (polarity inverting circuit) 9 are provided between the base B of the first switch element TR1 and the base B of the second switch element TR2, thereby providing the first switch. The signal supplied to the element TR1 is configured to invert its height and low and to be transmitted to the base of the second opening / closing element TR2 while being delayed for a required time.
According to this configuration, a necessary control signal is transmitted to the second opening / closing element TR2 only by supplying a drive control signal for starting the relay to the first opening / closing element, which will be described with reference to FIGS. A relay drive circuit can be realized.

FIG. 9 shows another embodiment of the present invention. A voltage / current exceeding the rated voltage is instantaneously generated only at the rising edge of the relay drive signal, and thereafter, the voltage / current within the rating is increased. The voltage control circuit 10 is configured so as to be generated.
That is, the voltage control circuit 10 detects the rising portion of the relay drive signal supplied to the base of the first switching element TR1, generates a drive current / voltage exceeding the rated voltage only for a required time, and supplies it to the relay drive coil. Although detailed description is omitted, it is only necessary to use digital circuit technology so that the voltage observation points 3, 4 and the like have waveforms similar to those already described. As a means for arbitrarily changing the power supply voltage, for example, a power supply circuit using a pulse width modulation method (PWM) can change the power supply voltage relatively easily and at high speed. Similarly to the above, a voltage that is 1.5 to 3 times or more than the rated voltage is instantaneously generated at the start of the relay drive, and the voltage is changed to a voltage within the rated value after the relay is activated.

The present invention can be variously modified without being limited to the examples described above. For example, even if a circuit that functions in the same way using a semiconductor element such as an FET instead of a constant voltage diode or constant current diode is configured, it may exhibit a transient phenomenon as described above when a control voltage is applied. In the same way, it can be used to promote the activation of the relay.
Further, although the single stable relay has been described in the embodiment, it will not be necessary to explain that a driving circuit having a startup promoting effect can be configured similarly for driving of the latching relay.

1 constant current diode, 2 ammeter, 3, 4 observation point, 5, 6 thermistor, 7 constant voltage diode, 8 delay circuit, 9 inverter circuit, 10 voltage control circuit (relay drive current / voltage generation circuit), K1 relay, SW1 relay movable contact (switch), TR1, TR2 switching element, R1, R2, R3 resistor, the power supply voltage exceeding _{V E} rated value, _{V z} Zener voltage

Claims (5)

A relay that controls opening and closing of the movable contact by energizing the drive coil, drive power supply means for supplying a voltage to the drive coil of the relay, and a route for supplying drive current / voltage from the drive power supply means to the drive coil A relay drive circuit including current / voltage control means arranged in
The drive power supply means supplies a voltage exceeding the rated value of the relay, and the current / voltage control means includes a first open / close switch element and a required time from a rising edge of the supplied drive current / voltage. A current / voltage exceeding the rated value of the relay is supplied to the drive coil of the relay, and the current / voltage within the rating of the relay is supplied to the drive coil of the relay after the required time elapses or is controlled. A relay drive circuit comprising a current / voltage control element.   2. The relay drive circuit according to claim 1, wherein the current / voltage control means is constituted by a constant current diode.   3. The relay drive circuit according to claim 2, wherein a resistor, a thermistor, or a circuit network of the resistor and the thermistor is connected in parallel with the constant current diode.   2. The relay drive circuit according to claim 1, wherein the current / voltage control means includes a constant voltage diode and a second open / close switch element connected in parallel with the constant voltage diode, and the first and second open / close switches. By controlling the switch element with a signal shifted in time, a current / voltage exceeding the rated value of the relay for a required time from the rising edge of the supplied drive current / voltage is supplied to the drive coil of the relay, and the required A relay driving circuit configured to operate or control so as to supply a current / voltage within a rating of the relay to a driving coil of the relay after a lapse of time.   5. The relay drive circuit according to claim 4, wherein the current / voltage control means is connected between the control end of the first on / off switch element and the control end of the second on / off switch element for a required time from the rising edge. A relay drive circuit comprising a signal delay means necessary for supplying a drive current / voltage exceeding a rated value.

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