JP2004362944A - Relay driving circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a relay driving circuit capable of holding and switching the contact connection of an electromagnetic relay by setting an input terminal at a prescribed logical level. <P>SOLUTION: In this relay driving circuit 101, if the logical level of an input voltage S10 to the input terminal 11 is suitably switched to a fist or second logical level, a first or second coil driving signal generating circuit 20, 30 outputs a first or second pulse-shaped coil driving signal S13, S23, the first or second driving coil 41, 42 of a two-winding latching type electromagnetic relay 40 is excited, a common contact 40c is automatically connected to a first contact 40a or a second contact 40b, or the common contact 40c can be automatically separated from the first contact 40a or the second contact 40b. Thereby, even if a current is not continuously sent, a contact connected condition can be held constant, and the contact connected condition can be arbitrarily changed when required. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a relay drive circuit, and in particular, connects a first contact of an electromagnetic relay to a common contact when a certain condition is satisfied, and connects a second contact to the common contact when the other condition is satisfied. It relates to a relay drive circuit for switching.
[0002]
[Prior art]
In this type of relay drive circuit, a state where no current flows in the drive coil of the relay is set to a steady state, and, for example, the first contact is connected to a common contact. When a current flows through the drive coil, the connection between the first contact and the common contact is disconnected, and the second contact is connected to the common contact. A relay used in this manner is called a single-stable relay, and a relay used in, for example, an "automatic fire alarm" is known (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. Hei 9-180075
[Problems to be solved by the invention]
In order to maintain the connection between the second contact and the common contact in such a relay, it is necessary to keep the current flowing through the drive coil, so that it consumes a considerable amount of power and has a relationship with the ambient temperature. There is a problem that the life of the relay is shortened. Conventional relay drive circuits need to maintain the connection between the first or second contact and the common contact, and predict in advance which of the first or second contact will continue to be connected to the common contact. As a solution to the problem when it is impossible, a latching relay may be used. In the case of using a latching type relay, the first contact or the second contact can be switched and connected to a common contact by supplying a pulse-shaped coil drive signal having a predetermined time width to the drive coil. After that, since the connection between the contacts can be maintained without applying a coil drive signal, the above-mentioned problem is eliminated.
[0005]
The present invention has been made in order to solve the above-mentioned problem, and it is necessary to maintain the connection between the first or second contact and the common contact, and to perform the connection of the first or second contact. It is impossible to predict in advance which of the two will continue to be connected to the common contact, and to cope with a case where the connection between the first or second contact and the common contact needs to be arbitrarily set during operation. An object of the present invention is to provide a relay drive circuit that can connect the first or second contact of a latching type electromagnetic relay to a common contact by setting the voltage of an input terminal to a predetermined logic level.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a pulse-like first or second coil drive signal from a first or second output terminal according to a change in a logic level of an input voltage applied to an input terminal. And the first or second coil drive signal of the two-winding latching type electromagnetic relay is excited by the output first or second coil drive signal, and the first or second contact of the electromagnetic relay is output. To a common contact, wherein the first set voltage having a logic level corresponding to the logic level of the input voltage applied to the input terminal, and a logic level opposite to the first set voltage A setting voltage generating circuit for generating a second setting voltage, and a first setting voltage, the first setting voltage corresponding to a changing edge at which the first setting voltage changes from the first logic level to the second logic level Then the pulse A first coil drive signal generating circuit for outputting a first coil drive signal of the first and second and connecting a first contact of the electromagnetic relay to a common contact, and a second set voltage. A second pulse driving signal is output in response to a transition edge that changes from the first logic level to the second logic level, and a second contact of the electromagnetic relay is connected to a common contact. And a coil drive signal generation circuit.
[0007]
According to such a configuration, the first or second coil drive signal generation circuit is selected by appropriately selecting the logic level of the input voltage applied to the input terminal of the relay drive circuit to the first or second logic level. Excites a first or second drive coil of a two-winding latching type electromagnetic relay, automatically connects a common contact to the first or second contact, or connects a common contact to the first contact. It can be automatically disconnected from the contact or the second contact. Therefore, it is necessary to maintain the connection between the first or second contact of the electromagnetic relay and the common contact by setting the voltage of the input terminal to a predetermined logic level, and to provide the first or second contact. It is not possible to predict in advance which of the two will continue to be connected to the common contact, and it is necessary to arbitrarily set the connection between the first or second contact and the common contact during operation. It is possible, and the first or second contact of the latching type electromagnetic relay can be freely connected to the common contact.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing a first embodiment of the relay drive circuit of the present invention. FIG. 2 is a truth table corresponding to the operation of the first and second pulse generation integrated circuits shown in FIG. FIG. 3 is an illustration to illustrate how the relay drive circuit shown in FIG. 1 can be used to separate an additional high frequency amplifying unit from a high frequency amplifying section of a wireless communication device. FIG. 4 is a diagram for explaining a state in which the relay drive circuit is mounted, FIG. 4 is a block diagram showing a second embodiment of the relay drive circuit of the present invention, and FIG. FIG. 9 is a diagram for explaining a state in which an additional high-frequency amplification unit is detachably attached to the high-frequency amplification unit of the wireless communication device in order to exemplify the usage.
[0009]
(First Embodiment)
The relay drive circuit 101 shown in FIG. 1 includes a set voltage generation circuit 10, a first coil drive signal generation circuit 20, and a second coil drive signal generation circuit 30, and is a two-winding latching type electromagnetic relay. Switch 40 contact connections. The setting voltage generation circuit 10 includes a resistor R11 having one end connected to the input terminal 11 and the other end connected to the power supply VDD, an inverter 12 having an input end connected to the input terminal 11, and an input end connected to the output terminal of the inverter 12. And an inverter 13 connected to the The input voltage S10 applied to the input terminal 11 is inverted in logic level by the inverter 12, and is output as the first set voltage S11. The first set voltage S11 is further inverted in logic level by the inverter 13 and output as the second set voltage S21.
[0010]
The first coil drive signal generation circuit 20 includes a first pulse generation integrated circuit 21 having a reset terminal RESET connected to an output terminal of the inverter 12, and a first pulse output from an output terminal Q of the pulse generation integrated circuit 21. A first amplifier that amplifies S12 (single pulse), outputs a first coil drive signal S13 from a first drive signal output terminal 29, and excites a first drive coil 41 of the latching type electromagnetic relay 40. 22. In this case, the terminal A of the first pulse generation integrated circuit 21 is connected to the ground via the resistor R21, the terminal B is connected to the power supply VDD via the resistor R22, the terminal CX is connected to the terminal RX_CX via the capacitor C21, and the terminal RX_CX is connected to the terminal RX_CX. They are connected to the power supply VDD via the resistor R23. As described above, when the first drive coil 41 is excited by the first coil drive signal S13, the first contact 40a and the common contact 40c of the electromagnetic relay 40 are connected, and the second contact 40b And the common contact 40c are disconnected.
[0011]
Note that the capacitor C21 and the resistor R23 in the first pulse generation integrated circuit 21 determine the pulse width of the first pulse output S12 and the first coil drive signal S13 output from the output terminal Q. This pulse width PW is set to be sufficiently longer than the response time of the first drive coil 41 of the electromagnetic relay 40. For example, when the capacitor C21 is 0.1 μF and the resistor R23 is 330 kΩ, the pulse width PW is about 33 msec. The operation of the first pulse generation integrated circuit 21 in such a connection state is as shown in the truth table shown in FIG. 2, in which the terminal A has a low logic level and the terminal B has a high logic level. Since it is set to “H”, a predetermined pulse width is output from the output terminal Q in response to the rising edge of the signal applied to the reset terminal RESET, as indicated by the portion marked with “#” in FIG. A first pulse output S12 of positive polarity (and a first coil drive signal S13) is output.
[0012]
The second coil drive signal generation circuit 30 includes a second pulse generation integrated circuit 31 having a reset terminal RESET connected to the output terminal of the inverter 13, and a second pulse generation integrated circuit 31 from the output terminal Q of the pulse generation integrated circuit 31. A second amplifier 32 that amplifies the pulse output S22, outputs a second coil drive signal S23 from a second drive signal output terminal 39, and excites a second drive coil 42 of the latching type electromagnetic relay 40. . In this case, the terminal A of the second pulse generating integrated circuit 31 is connected to the ground via the resistor R31, the terminal B is connected to the power supply VDD via the resistor R32, the terminal CX is connected to the terminal RX_CX via the capacitor C31, and the terminal RX_CX is connected to the terminal RX_CX. Each is connected to the power supply VDD via the resistor R33. As described above, when the second drive coil 42 is excited by the second coil drive signal S23, the second contact 40b and the common contact 40c are connected, and the first contact 40a and the common contact 40c are connected. And is separated.
[0013]
Further, the capacitor C31 and the resistor R33 in the above-described second pulse generation integrated circuit 31 are connected to the second pulse output S22 (and the second coil drive signal S23) in the same manner as in the first pulse generation integrated circuit 21. The pulse width PW is determined. Therefore, the operation of the second pulse generation integrated circuit 31 in such a connection state is the same as the operation of the first pulse generation integrated circuit 21, and is applied to the reset terminal RESET of the second pulse generation integrated circuit 31. A second pulse output S22 (second coil drive signal S23) of a positive polarity having a predetermined pulse width is output from the output terminal Q in response to the rising edge of the second set voltage. Note that the first and second pulse generation integrated circuits 21 and 31 can use Dual Retriggerable Monostable Multivibrators, which are known as standard logic ICs. A number to which a unique code is added for each is available.
[0014]
Next, an example of how the above-described relay drive circuit 101 of FIG. 1 is used will be described with reference to FIG. FIG. 3 shows a state in which an additional high-frequency amplification unit is detachably attached to the high-frequency amplification unit of the wireless communication device. The high frequency amplifying unit 201 includes a high frequency amplifying unit 211, the relay drive circuit 101 and the two-winding latching type electromagnetic relay 40 shown in FIG. 1, and an output of the high frequency amplifying unit 211 and a signal from a common terminal 40 c of the electromagnetic relay 40. And a power combiner 213 that combines the signals and outputs the result to the output terminal 113. The high-frequency amplification unit 211 includes an amplifier 211a for amplifying a high-frequency signal applied to the input terminal 111. The additionally mounted high-frequency amplification unit 212 includes an amplifier 212a for amplifying the high-frequency signal applied to the input terminal 112, and a ground. Connection terminal 212b. In this case, it is preferable that both the high-frequency amplification units 211 and 212 are configured to be detachable, and the high-frequency amplification unit 211 is made to have the same configuration as the high-frequency amplification unit 212 so as to facilitate the unification of both manufacturing methods. Thus, the high-frequency amplification unit 211 may include an unused ground connection terminal.
[0015]
In the example of FIG. 3, when the high-frequency amplification unit 212 is not mounted and the high-frequency amplification unit 212 is mounted, the input terminal 11 of the relay drive circuit 101 is connected to the ground via the ground terminal 212b. You. Therefore, the logic level of the input voltage S10 to the input terminal 11 of the relay drive circuit 101 changes from “H” to “L”. In response to this change, the first set voltage S11 rises from "L" to "H", and the second set voltage S21 falls from "H" to "L". As a result, the first coil drive signal S13 is output to the output terminal 29, the first drive coil 41 of the electromagnetic relay 40 is excited, and the first contact 40a is connected to the common contact 40c. Therefore, the power combiner 213 combines the output of the high frequency amplification unit 211 and the output of the high frequency amplification unit 212 and outputs the result to the output terminal 113.
[0016]
As described above, when the high-frequency amplification unit 212 is attached to the high-frequency amplification unit 202 and the high-frequency amplification unit 212 is pulled out from the high-frequency amplifier 202, the input terminal 11 of the relay drive circuit 101 is opened and the power supply voltage is reduced. The potential is raised to VDD. Therefore, the logic level of the input voltage S10 to the input terminal 11 of the relay drive circuit 101 changes from "L" to "H". In response to this change, the first set voltage S11 falls from "H" to "L", and the second set voltage S12 rises from "L" to "H". As a result, the second coil drive signal S13 is output to the second drive signal output terminal 39, the second drive coil 42 of the electromagnetic relay 40 is excited, and the second contact 40b is connected to the common contact 40c. You. Therefore, the line where the amplifier 212a was connected to the power combiner 213 until now is terminated with the characteristic impedance. The reason for terminating in this manner is that if one of the power combiners is opened without terminating with the characteristic impedance, the frequency characteristics of the other power reflection may be disturbed.
[0017]
(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. The relay drive circuit 102 shown in FIG. 4 includes a set voltage generation circuit 50, a first coil drive signal generation circuit 60, a second coil drive signal generation circuit 70, and an addition circuit 80. The contact connection of the line latching type electromagnetic relay 90 is switched. The setting voltage generation circuit 50 has a resistor R51 having one end connected to the input terminal 51 and the other end connected to the power supply VDD, and an input terminal connected to the input terminal 51, and a logic of an input voltage T10 applied to the input terminal 51. An inverter 52 for inverting the level and outputting a first set voltage T11; and an input terminal connected to the output end of the inverter 52, for inverting the logic level of the first set voltage T11 to generate a second set voltage T21. And an inverter 53 for outputting.
[0018]
The first coil drive signal generation circuit 60 includes a first pulse generation integrated circuit 61 having a reset terminal RESET connected to an output terminal of the inverter 52, and a first pulse generation integrated circuit 61 output from an output terminal Q of the pulse generation integrated circuit 61. A first amplifier 62 that amplifies the pulse output T12 and outputs a first coil drive signal T13 from a first output terminal 69. In this case, the terminal A of the first pulse generation integrated circuit 61 is connected to the ground via the resistor R61, the terminal B is connected to the power supply VDD via the resistor R62, the terminal CX is connected to the terminals RX and CX via the capacitor C61, and the terminal RX and CX are connected to the power supply VDD via the resistor R63. The operation of the first pulse generation integrated circuit 61 in such a connection state performs the same operation as that of the first pulse generation integrated circuit 21 shown in FIG. That is, the first pulse output T12 of positive polarity is output in response to the rising edge of the signal applied to the reset terminal RESET.
04/10
[0019]
The second coil drive signal generation circuit 70 includes a second pulse generation integrated circuit 71 having a reset terminal RESET connected to an output terminal of the inverter 53, and a second pulse output from the output terminal Q of the pulse generation integrated circuit 71. A second amplifier 72 that amplifies T22, inverts the logic, and outputs a second coil drive signal T23 from a second output terminal 79. In this case, the second pulse generation integrated circuit 71 has the same function as the first pulse generation integrated circuit 61, but the second amplifier 72 has the resistors R74 and R74 so as to invert and amplify the second pulse output T22. The bias by R75 and R76 is given.
[0020]
The adder circuit 80 supplies the amplifier 81 biased by the resistors R83 and R84 and the first and second coil drive signals T13 and T23 from the first and second output terminals to the input terminal of the amplifier 81. It has resistors R81 and R82. In this case, it goes without saying that the first and second coil drive signals T13 and T23 from the first and second output terminals 69 and 79 do not occur at the same time but only one of them. When the input voltage T10 at the input terminal 51 changes from “H” to “L”, the adding circuit 80 receives the first coil drive signal T13 of the positive polarity from the first output terminal 69, A coil drive signal TDV is output to excite the drive coil 91 of the electromagnetic relay 90. When the drive coil 91 is driven by the positive coil drive signal TDV, the first contact 90a and the common contact 90c are connected, and the second contact 90b and the common contact 40c are disconnected. When the input voltage T10 at the input terminal 51 changes from “L” to “H”, the addition circuit 80 receives the negative second coil drive signal T23 from the second output terminal 79 and outputs the output terminal 89. Outputs a negative coil drive signal TDV to excite the drive coil 91 of the electromagnetic relay 90. When the drive coil 91 is driven by the negative coil drive signal TDV, the second contact 90b and the common contact 90c are connected, and the first contact 90a and the common contact 40c are disconnected.
[0021]
Next, an example of how the above-described relay drive circuit of FIG. 4 is used will be described with reference to FIG. FIG. 5 shows a state in which an additional high-frequency amplification unit is detachably attached to the high-frequency amplification unit of the wireless communication device, as in the example of FIG. The high-frequency amplifying unit 202 includes a high-frequency amplifying unit 211, the relay drive circuit 102 and the single-winding latching-type electromagnetic relay 90 shown in FIG. And a power combiner 213 that combines the signals and outputs the result to the output terminal 113. This high-frequency amplifier 202 is the same as that of FIG. 3 except that a one-winding latching type electromagnetic relay 90 and a relay driving circuit 102 are used instead of the two-winding latching type electromagnetic relay 40 and the relay driving circuit 101. Can serve the purpose.
[0022]
In the example of FIG. 5, when the high-frequency amplification unit 212 is mounted on the high-frequency amplification unit 202 when the high-frequency amplification unit 212 is not mounted, the input terminal 51 of the relay drive circuit 102 is connected via the ground terminal 212b. Connected to ground. Therefore, the logic level of the input voltage T10 to the input terminal 51 of the relay drive circuit 102 changes from “H” to “L”. In response to this change, the first set voltage T11 rises from "L" to "H", and the second set voltage T21 falls from "H" to "L". As a result, a positive coil drive signal TDV is output from the output terminal 89 of the adder circuit 80, the drive coil 91 of the electromagnetic relay 90 is excited, and the first contact 90a is connected to the common contact 90c. Therefore, the power combiner 213 combines the output of the high frequency amplification unit 211 and the output of the high frequency amplification unit 212 and outputs the result to the output terminal 113.
[0023]
As described above, when the high frequency amplification unit 212 is attached to the high frequency amplification unit 202 and the high frequency amplification unit 212 is pulled out of the high frequency amplification unit 202, the input terminal 51 of the relay drive circuit 102 is opened. The potential is raised to the potential of the power supply voltage VDD. Therefore, the logic level of the input voltage T10 to the input terminal 51 of the relay drive circuit 102 changes from "L" to "H". In response to this change, the first set voltage T11 falls from "H" to "L", and the second set voltage T21 rises from "L" to "H". As a result, the second pulse output T22 of positive polarity is output from the second pulse generation integrated circuit 71, logically inverted by the amplifier 72, and output as the second coil drive signal T23. The addition circuit 80 receives the second coil drive signal T23 from the second coil drive signal generation circuit 70, outputs a negative coil drive signal TDV, and excites the drive coil 91 of the electromagnetic relay 90. By this excitation, the second contact 90b and the common contact 90c are connected, and the first contact 90a and the common contact 90c are disconnected. Note that the description has been made on the assumption that the amplification factors of the amplifiers 22, 32, 62, 72, and 81 shown in FIGS. 1 and 4 are “1”. When it is necessary to set another amplification factor, it goes without saying that it is necessary to set it so as to match the amplification factor.
[0024]
【The invention's effect】
Since the relay drive circuit of the present invention is configured as described above, by appropriately switching the logic level of the input voltage S10 applied to the input terminal 11 to the first or second logic level, the first Alternatively, the second coil drive signal generation circuits 20 and 30 excite the first or second drive coils 41 and 42 of the two-winding latching type electromagnetic relay 40 and change the common contact 40c to the first contact 40a or the second contact. The second contact 40b can be automatically connected, or the common contact 40c can be automatically disconnected from the first contact 40a or the second contact 40b. Therefore, it is necessary to maintain the contact connection of the electromagnetic relay by setting the input terminal to a predetermined logic level, and to predict in advance which of the first or second contact is to be continuously connected to the common contact. If it is not possible, and it is necessary to arbitrarily set the connection between the first or second contact and the common contact during operation, it is possible to respond without continuously supplying current to the electromagnetic relay Thus, the first or second contact of the latching type electromagnetic relay can be freely connected to the common contact.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of a relay drive circuit according to the present invention.
FIG. 2 is a diagram for explaining a truth table corresponding to the operation of the first and second pulse generation integrated circuits shown in FIG. 1;
FIG. 3 shows an additional high-frequency amplification unit detachably mounted on the high-frequency amplification unit of the wireless communication device to illustrate how the relay drive circuit shown in FIG. 1 is used. It is a figure for explaining a state.
FIG. 4 is a block diagram showing a second embodiment of the relay drive circuit of the present invention.
FIG. 5 shows an additional high-frequency amplification unit detachably mounted on the high-frequency amplification unit of the wireless communication device to illustrate how the relay drive circuit shown in FIG. 4 is used; It is a figure for explaining a state.
[Explanation of symbols]
10 Set voltage generation circuits 11, 51 Input terminals 12, 13, 52, 53 Inverters 20, 60 First coil drive signal generation circuits 21, 61 First pulse generation integrated circuits 22, 32, 62, 72, 81 Amplifier 29 , 69 First drive signal output terminal 30, 70 Second coil drive signal generation circuit 31 Second pulse generation integrated circuit 39, 79 Second drive signal output terminal 40 Two-winding latching type electromagnetic relays 40a, 90a One contact 40b, 90b Second contact 40c, 90c Common contact 41 First drive coil 42 First drive coil 80 Addition circuit 90 Single winding latching electromagnetic relay 91 Drive coils 101, 102 Relay drive circuits 201, 202 High frequency amplification units 211 and 212 High frequency amplification unit 213 Power combiner

Claims (1)

A first or second coil drive signal is output from the first or second output terminal in response to a change in the logic level of the input voltage applied to the input terminal, and the output first or second coil drive signal is output. A relay drive circuit for exciting a first or second drive coil of a two-winding latching type electromagnetic relay with a coil drive signal to connect a first contact or a second contact of the electromagnetic relay to a common contact,
A set voltage for generating a first set voltage having a logic level corresponding to the logic level of the input voltage applied to the input terminal, and a second set voltage having a logic level opposite to the first set voltage A generation circuit;
Receiving a first set voltage, outputting a pulse-shaped first coil drive signal in response to a change edge at which the first set voltage changes from the first logic level to the second logic level; A first coil drive signal generation circuit for connecting a first contact of the electromagnetic relay to a common contact;
Receiving a second set voltage, outputting a pulse-shaped second coil drive signal in response to a change edge at which the second set voltage changes from the first logic level to the second logic level; A second coil drive signal generation circuit for connecting a second contact of the electromagnetic relay to a common contact.

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