JP3965588B2 - Inductive load controller - Google Patents

Description

  The present invention relates to an inductive load control device, and in particular, is applied to a general inductive load (for example, a motor or a DC motor), can avoid the influence of a spark due to the operation of a switch, and the life of a control contact of a relay switch. The present invention relates to an inductive load control device that can improve reliability and reliability.

  At present, as shown in FIG. 1 (US Pat. No. 6,487,062 B1), a control system for a general commercially available inductive load (for example, a motor or a DC motor) supplies power to a magnetic excitation coil. When this occurs, the metal elastic piece 134 of the relay switch 13 moves from the contact 132 to the contact 133, and the contact 131 and the contact 133 become conductive. At this time, the power of the DC power supply 15 is supplied from the anode end to the relay 11. Power is supplied to the inductive load 10 via the contact 133, the metal elastic piece 134, and the contact 131, and the contact 131a of the relay switch 13a of the relay 12, the metal elastic piece 134a, and the contact 132a are connected. Via the field effect transistor 14 to the DC power supply 15, and at this time, it is also necessary to provide a conduction voltage to the gate terminal of the field effect transistor 14. , And the by controlling the inductive load 10 by conduction voltage, the circuit to flow in the forward direction is formed.

Conversely, when the relay 12 supplies power to the magnetic excitation coil, the metal elastic piece 134a of the relay switch 13a moves from the contact 132a to the contact 133a, and the contact 131a and the contact 133a become conductive. The power of the DC power supply 15 is supplied to the inductive load 10 via the contact 133a of the relay switch 13a of the relay 12, the metal elastic piece 134a, and the contact 131a, and the relay switch 13 of the relay 11 The current flows through the contact 131, the metal elastic piece 134, and the contact 132 to the DC power source 15 via the field effect transistor 14, and at this time, a conduction voltage is provided to the gate terminal of the field effect transistor 14. If the inductive load 10 is controlled by the conduction voltage, a circuit that flows in the opposite direction is formed.

  However, this has the following drawbacks.

(1) In the conventional control method, after a predetermined magnetic excitation voltage is provided to the relay 11 or the relay 12, a control voltage can be provided to the gate terminal of the field effect transistor 14 for the first time. Complexity increases production costs.

(2) Although it is necessary to form a control voltage at the gate terminal of the field effect transistor 14, this control voltage is often generated first because the circuit is affected by the cause of the abnormality. If the magnetic excitation voltage is generated immediately after that, the contact 133 or the contact 133a of the relay 11 or the relay 12 is easily damaged by the instantaneous current generated by driving the inductive load 10.

(3) As shown in FIG. 1, the user needs to add another control system in which the relay 11 and the relay 12 operate before the field effect transistor 14, and the field effect transistor 14 The drive needs to be delayed by parts, but it is difficult to control.

(4) When the relay 11 and the relay 12 operate at the same time, the current that originally flows into the load generates a spark at the contacts of the relay switches 13 and 13a of the relays 11 and 12, and this damages the contacts. easy.

  The main object of the present invention is to provide an inductive load control device that is simpler to control and can reduce manufacturing costs.

  Another object of the present invention is to provide an inductive load control device that can avoid the occurrence of sparks when turning on and off, improve circuit reliability, and improve the service life of components.

Another object of the present invention is to provide an inductive load control device that can effectively protect relay contacts and improve the service life and reliability of the relay contacts.

  In order to achieve the above object, a first invention of the present application is an inductive load control device including a power source, a first control group, a second control group, and an inductive load. The first control group is connected in series with the power source, and includes a relay switch, a relay, and one field effect transistor, and the relay switch has one common contact and one piece. A common spring is connected to a power source, a magnetically controlled strip spring is controlled by the relay and localized to a normal off contact or a normal on contact, and A current-on contact is connected to a gate end of a field-effect transistor, the current-off contact is connected to a drain end of the field-effect transistor, a source end of the field-effect transistor is connected to a power source, and The two control groups are connected in series with the power source and in parallel with the first control group, and are composed of a relay switch, a relay, and one field effect transistor, and the relay switch has one common contact and one piece. A common spring is connected to a power source, a magnetically controlled strip spring is controlled by the relay and localized to a normal off contact or a normal on contact, and An ordinary on contact is connected to a gate end of a field effect transistor, the ordinary off contact is connected to a drain end of the field effect transistor, a source end of the field effect transistor is connected to a power source, and the inductive load is An inductive load control device characterized by connecting a current-off contact of a relay switch of a first control group and a current-off contact of a relay switch of a second control group It is summarized in that it.

  In the second invention of the present application, the relay switch of the first control group is connected to the anode end of the power source through a common contact, the field effect transistor is N type, and the source end of the N type field effect transistor is the power source. The relay switch of the second control group is connected to the anode end of the power source through a common contact, the field effect transistor is N type, and the source end of the N type field effect transistor is the power source The gist of the present invention is the inductive load control device according to the first aspect of the present invention, characterized in that the inductive load control device is connected to the cathode end of the present invention.

  In the third invention of the present application, the relay switch of the first control group is connected to the cathode end of the power source through a common contact, the field effect transistor is P type, and the source end of the P type field effect transistor is the power source. The relay switch of the second control group is connected to the cathode end of the power source through a common contact, the field effect transistor is P type, and the source end of the P type field effect transistor is the power source The gist of the present invention is the inductive load control device according to the first invention of the present application, characterized in that it is connected to the anode end.

  The gist of the fourth invention of the present application is the inductive load control device according to any one of the first to third inventions of the half-eye, wherein the inductive load is a motor.

The fifth invention of the present application is summarized as the inductive load control device according to the fourth invention of the present application, wherein the motor is applied to a mechanism control device of a linear actuator.

According to the inductive load control device according to the present invention, the control becomes simpler, the manufacturing cost can be reduced, the occurrence of sparks when turning on / off can be avoided, the reliability of the circuit is improved, and the use of parts The service life is improved, the relay contacts are effectively protected, and the service life and reliability of the relay contacts can be improved.

  Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  The first embodiment of the inductive load control device according to the present invention uses an N-type field effect transistor. As shown in FIG. 2, the circuit includes a power supply 20, a resistor 21, and a first control set 30. And a second control set 40 and an inductive load 50 (see FIG. 2).

  The power source 20 is assembled in a circuit and has an anode end 20a and a cathode end 20b.

  The resistor 21 is for detecting current, and is connected in series with the cathode end 20 b of the power supply 20.

  The first control set 30 is connected in series between the anode end 20a of the power source 20 and the resistor 21, and includes a relay switch 31, a relay 32, a single field effect transistor 33, and a diode 34. The field effect transistor 33 is an N type, and the relay switch 31 forms a current-off contact 312 and a current-on contact 313 by one common contact 311 and a piece spring 35, and the common contact 311 is a power source 20. The relay 32 controls the magnetic control strip spring 35, connects the current-on contact 313 to the gate end 33a of the field effect transistor 33, and connects the current-off contact 312 to the field effect transistor 312. Connected to the drain end 33b of the transistor 33, the source end 33c of the field effect transistor 33 is connected to the resistor 21, By connecting common contact 311 and current-off contacts 312 and across diode 34 a respective switch 31, equipped circuits are formed.

  The second control set 40 is connected in series between the anode end 20a of the power source 20 and the resistor 21, and is connected in parallel with the first control set 30, and includes a relay switch 41, a relay 42, and one field effect. The field effect transistor 43 is an N type, and the relay switch 41 includes a common contact 411 and a piece-like spring 45, and a current-off contact 412 and a current-on contact. 413, the common contact 411 is connected to the anode end 20a of the power source 20, the relay 42 controls the magnetic control strip spring 45, and the current-on contact 413 is connected to the gate end of the field effect transistor 43. 43a, the current-off contact 412 is connected to the drain end 43b of the field effect transistor 43, and the field effect transistor 43 Connect the source terminal 43c and the resistor 21, by connecting the common contact 411 and current-off contacts 412 and both ends of the diode 44 each relay switch 41, equipped circuits are formed.

  The inductive load 50 is a motor, and both ends thereof are connected to a current-off contact 312 of the relay switch 31 and a current-off contact 412 of the relay switch 41, and both ends of the inductive load 50 are a diode 34 and a diode 44. It will be in the state of connecting to each.

  A second embodiment of the inductive load control device according to the present invention uses a P-type field effect transistor, and as shown in FIG. 3, its power source 20, resistor 21, first control set 30, The layout of the two control group 40 and the inductive load 50 is the same as that of the first embodiment, and the field effect transistors 33 and 43 are P type, but the first control group 30 and the second control group 40 Therefore, in contrast to the first embodiment, the common contacts 411 and 311 are connected to the resistor 21 in reverse, and the source ends 33c and 43c of the field effect transistors 33 and 43 are also connected. On the contrary, the power source 20 is connected to the anode end 20a.

  The gate terminals 33a and 43a of the N-type field effect transistors 33 and 43 according to the present invention are connected to the current-on contact 313 of the relay switch 31 and the current-on contact 413 of the relay switch 41, respectively. The start signal of the field effect transistors 33 and 43 is controlled, while the second embodiment according to the present invention adopts a P type field effect transistor instead of an N type field effect transistor, as shown in FIG. In addition, the first control group 30 and the second control group 40 are installed in reverse so that the positive voltage starting system of the N type field effect transistor is converted to the negative voltage starting system of the P type field effect transistor. .

  First, the first embodiment will be described. After the coil of the relay 42 of the second control group 40 is excited, the piece spring 45 of the relay switch 41 is moved, that is, the piece spring 45 is moved from the current OFF contact 412 to the current ON contact 413. The common contact 411 and the normally-on contact 413 become conductive, and the power supply 20 supplies a positive voltage to the gate terminal 43a of the N-type field effect transistor 43, so that the drain terminal of the N-type field effect transistor 43 is supplied. 43b and the source end 43c become conductive.

  At this time, the power source 20 flows from the anode end 20a to the common contact 311 of the relay switch 31 of the first control group 30, and the half spring 35 of the relay switch 31 is positioned at the current-off contact 312. In this embodiment, the inductive load 50 is a motor, and the current is supplied from the other end of the inductive load 50 to the second control set 40. Through the drain end 43b of the N-type field effect transistor 43, the current flows through the source end 43c to the resistor 21 for detecting current, and finally returns to the cathode end 20b of the power source 20 to form a current circuit. The inductive load 50 (motor) starts operation in the positive direction.

  Since the present invention effectively configures the current circuit, the passing current can be detected by the resistor 21, and the voltage value is read from both ends of the resistor 21, and the voltage value monitors the amount of current flowing through the load. And the purpose of limiting or controlling the current can be achieved.

  Similarly, after the coil of the relay 32 of the first control set 30 of the first embodiment according to the present invention is excited, the piece spring 35 of the relay switch 31 is moved, that is, the piece spring 35 is normal. The common contact 311 and the normal on contact 313 are brought into conduction, and the power source 20 supplies a positive voltage to the gate terminal 33a of the N-type field effect transistor 33. Then, the drain end 33b and the source end 33c of the N-type field effect transistor 33 become conductive.

  At this time, the power source 20 flows from the anode end 20a to the common contact 411 of the relay switch 41 of the second control group 40, and the half spring 45 of the relay switch 41 is positioned at the normal-off contact 412. Flows into the inductive load 50 in the opposite direction to drive the inductive load 50, and the current flows from the other end of the inductive load 50 to the drain end of the N-type field effect transistor 33 of the first control group 30. The current flows into the resistor 21 for detecting the current via the source end 33c via the source 33b, and finally returns to the cathode end 20b of the power source 20 to form a current circuit. The inductive load 50 (motor) is in the reverse direction. Start driving.

  Next, a second embodiment will be described. After the coil of the relay 42 of the second control group 40 is excited, the piece spring 45 of the relay switch 41 is moved, that is, the piece spring 45 is moved from the current OFF contact 412 to the current ON contact 413. The common contact 411 and the normally-on contact 413 become conductive, and the power supply 20 supplies a negative voltage to the gate terminal 43a of the P-type field effect transistor 43, so that the drain terminal of the P-type field effect transistor 43 43b and the source end 43c become conductive.

  At this time, the power source 20 passes through the P-type field effect transistor 43 of the second control set 40 and flows into the inductive load 50 to drive the inductive load 50. The current passing through the inductive load 50 is The current flows into the resistance 21 for detecting the current via the current-off contact 312 and the common contact 311 of the relay switch 31 of the first control group 30, and finally returns to the power source 20 to form a current circuit, which leads to induction. The load 50 starts to operate in the positive direction.

  Similarly, after the coil of the relay 32 of the first control set 30 according to the present invention is energized, the piece spring 35 of the relay switch 31 is moved, that is, the piece spring 35 is recurrent from the ordinary off contact 312. At this time, the common contact 311 and the recurrent on contact 313 become conductive, and the power supply 20 supplies a negative voltage to the gate terminal 33a of the P-type field effect transistor 33. The drain end 33b and the source end 33c of the type field effect transistor 33 become conductive.

  At this time, the current of the power source 20 passes through the N-type field effect transistor 33 and then drives the inductive load 50 in the reverse direction. The current passing through the inductive load 50 is the current of the second control group 40. The current flows into the resistor 21 for detecting the current via the common contact 411 by the single spring 45 via the off contact 412, and finally returns to the power supply 20 to form a current circuit, thereby forming the inductive load 50. Starts driving in the opposite direction.

  The control principle of the present invention is that a combination of a relay and a field effect transistor allows the on / off of the field effect transistor to avoid the occurrence of a spark, and the relay switch of the other set of relays of the present invention has a normally off configuration. Therefore, damage to the contact due to sparks can be avoided.

  When one set of relay switches drives and drives the inductive load 50, and the other set of relay switches operate simultaneously, the two sets of field effect transistors are turned on at the same time. The current charged before the load is discharged at the moment when the two field effect transistors are turned on, and there is no actual contact, so the relay contact is protected and the service life is improved. Failure can also be prevented.

  Since both ends of the diodes 34 and 44 according to the present invention are respectively connected to the common contact and the normally-off contact of the relay switch, when the current supply to the relay coil stops, the energy stored in the inductive load 50 is stored. Flows to the power source 20 through the diodes 34 and 44, flows into the common contact of each relay switch, forms a current circuit, and consumes the stored energy. At this time, any one of the relay switches The energy of the contact to be opened is also immediately consumed by the diodes 34 and 44, so that no spark is generated at the common contacts 411 and 311 of the relay switch, and the purpose of protecting the contact is achieved (the principle of reverse rotation) The same).

In the present invention, the field effect transistors 33 and 43 are first activated by the first control group 30 and the second control group 40, and the user activates the field effect transistors after waiting for a delay time after the relay is activated. There is no need to start up, control is simpler and manufacturing costs can be reduced, while the present invention is based on the method of connecting the gate ends of two field effect transistors and the normally-off contacts of two relay switches. When two sets of relays are activated, the current generated by the load flows inside the field-effect transistor, and no spark is generated at the contact of the relay. Therefore, damage due to the spark of the contact can be prevented, and the circuit reliability can be prevented. And service life of parts are improved.

It is the conventional circuit schematic. 1 is a system diagram of a first embodiment according to the present invention. It is a system diagram of the second embodiment according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inductive load 11,12 Relay 13,13a Relay switch 131,131a Common contact 132,132a Current off contact 133,133a Current on contact 134,134a Metal elastic piece 14 Field effect transistor 15 DC power supply 20a Anode end 20b Cathode end 21 resistor 30 first control group 31 relay switch 311 common contact 312 current-off contact 313 current-on contact 32 relay 33 field effect transistor 33a gate end 33b drain end 33c source end 34 diode 35 piece spring 40 second control group 41 relay Switch 411 Common contact 412 Ordinary off contact 413 Ordinary on contact 42 Relay 43 Field effect transistor 43a Gate end 43b Drain end 43c Source end 44 Diode 45 Strip spring 50 Inductive load

Claims (5)

In an inductive load control device including a power source, a first control group, a second control group, and an inductive load,
The power source has an anode end and a cathode end,
The first control group is connected in series with the power source, and includes a relay switch, a relay, and one field effect transistor, and the relay switch includes a common contact and a single spring and a current-off contact. An ordinary on-contact, the common contact is connected to a power source, a magnetically controlled leaf spring is controlled by the relay, and is localized to an ordinary-off contact or an ordinary-on contact, and the ordinary-on-contact is a field effect transistor The current-off contact is connected to the drain end of the field effect transistor, the source end of the field effect transistor is connected to the power source,
The second control group is connected in series with the power source and in parallel with the first control group, and includes a relay switch, a relay, and one field effect transistor, and the relay switch has one common contact. And a half-spring to form a current-off contact and a current-on contact, the common contact is connected to a power source, and the magnetic control piece-shaped spring is controlled by the relay and is localized to a current-off contact or a current-on contact, And the current-on contact is connected to the gate end of a field effect transistor, the current-off contact is connected to the drain end of the field effect transistor, and the source end of the field effect transistor is connected to a power source,
The inductive load is connected to a current-off contact of a relay switch of the first control set and a current-off contact of a relay switch of the second control set,
Inductive load control device.
The relay switch of the first control group is connected to the anode end of the power source at a common contact, the field effect transistor is N type, and the source end of the N type field effect transistor is connected to the cathode end of the power source,
The relay switch of the second control group is connected to the anode end of the power source through a common contact, the field effect transistor is N type, and the source end of the N type field effect transistor is connected to the cathode end of the power source. The inductive load control device according to claim 1.
The relay switch of the first control group is connected to the cathode end of the power source at a common contact, the field effect transistor is P type, and the source end of the P type field effect transistor is connected to the anode end of the power source,
The relay switch of the second control group is connected to the cathode end of the power source through a common contact, the field effect transistor is P type, and the source end of the P type field effect transistor is connected to the anode end of the power source. The inductive load control device according to claim 1.
The inductive load control device according to claim 1, wherein the inductive load is a motor.
  The inductive load control device according to claim 4, wherein the motor is applied to a mechanism control device of a linear actuator.

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