JPH0742106U - Load drive - Google Patents

Abstract

(57) [Summary] [Purpose] A self-holding solenoid with different suction pulse voltage and return pulse voltage can be driven using a bridge driver IC. A parallel connection circuit of a diode D and a resistor R is connected in a connection passage between a self-holding solenoid 1 and an output terminal OUT1 of a bridge driver IC2. Input terminal IN
When the control signals of "H" and "L" are given to 1 and IN2, "H" level is generated at the output terminal OUT1 and "L" signal is generated at OUT2, and the current flows through the route of OUT1 → D → 1 → OUT2. A pulse voltage of 12 V is applied to the self-holding solenoid 1. When control signals of "L" and "H" are given to IN1 and IN2, signals of "L" and "H" are generated at OUT1 and OUT2, current flows through the route of OUT2 → 1 → R → OUT1 and self-holding A pulse voltage of 6 V is applied to the mold solenoid 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a load drive device suitable for use in driving a load such as a self-holding type solenoid having different suction pulse voltage and return pulse voltage.

[0002]

[Prior art]

 FIG. 2 shows an example of a drive circuit for a conventional self-holding solenoid. In the figure, 1 is a self-holding solenoid, Tr1 to Tr4 are transistors, and the self-holding solenoid 1 and transistors Tr1 to Tr4 are connected in the form of an H bridge. That is, the collector of the transistor Tr1 and the collector of the transistor Tr2 are connected via a resistor r (connection point P1), the collector of the transistor Tr3 and the collector of the transistor Tr4 are connected (connection point P2), and the connection point P1 is connected. The self-holding solenoid 1 is connected to the connection point P 2.

In this drive circuit, the on / off state of the transistors Tr1 to Tr4 is controlled by a control signal from a CPU (not shown). That is, as the first input condition, if a control signal of "L" level is given to the transistor Tr1 and "H" level is given to the transistor Tr4, both the transistors Tr1 and Tr4 are turned on, and the self-holding solenoid 1 is directed in the direction A in the figure. And a pulse voltage (suction pulse voltage) of 12 V (Vcc) is applied to the self-holding solenoid 1. This causes the self-holding solenoid 1 to perform a suction operation. On the other hand, if a control signal of “L” level is given to the transistor Tr3 and a control signal of “H” level is given to the transistor Tr2 as the second input situation, both the transistors Tr3 and Tr2 are turned on, and the self-holding solenoid 1 is turned on. A current flows in the direction B in the figure, and a pulse voltage (return pulse voltage) of about 6 V divided by the resistance r is applied to the self-holding solenoid 1. This causes the self-holding solenoid 1 to return.

[0004]

However, according to such a conventional drive circuit, a protection circuit or the like for preventing the transistors Tr1 (Tr3) and Tr2 (Tr4) from being turned on at the same time is provided. If this is added, the circuit becomes complicated and the circuit scale becomes large. As a solution to this problem, it is conceivable to use a commercially available bridge driver IC with a built-in protection circuit. However, in this type of bridge driver IC, four transistors are already packaged in the form of an H-bridge, so that the resistor r cannot be connected in the form as shown in FIG. Therefore, in the past, the drive of the self-holding solenoid 1 using the bridge driver IC has been postponed.

The present invention has been made to solve such a problem, and an object thereof is to use a bridge driver IC to load a self-holding solenoid or the like having different suction pulse voltage and return pulse voltage. The object is to provide a load drive device that can be driven by the following methods.

[0006]

[Means for Solving the Problems]

 In order to achieve such an object, the present invention sets the first output terminal to the “H” level and the second output terminal to the “L” level according to the first input status, and the second input status. Connect the first output terminal to the “L” level and the second output terminal to the “H” level according to the above, and the drive circuit and the first output terminal and the second output terminal of this drive circuit. And a parallel connection circuit of a diode and a resistor connected in a connection path between the load and the first output terminal of the drive circuit.

[0007]

[Action]

 Therefore, according to the present invention, if the first output terminal of the drive circuit becomes the “H” level and the second output terminal becomes the “L” level according to the first input situation, the first output terminal → diode Current flows in the route of (resistance) → load → second output terminal, the first output terminal of the drive circuit is at "L" level and the second output terminal is at "H" level depending on the second input situation. Then, a current flows through the path of the second output terminal → load → resistance (diode) → first output terminal.

[0008]

【Example】

 Hereinafter, the present invention will be described in detail based on embodiments. FIG. 1 is a diagram showing a drive circuit of a self-holding solenoid which is an embodiment of the present invention. In the figure, 1 is a self-holding solenoid, and 2 is a bridge driver IC. In the bridge driver IC2, four transistors have already been packaged in the form of an H bridge, and a protection circuit is also built in.

The bridge driver IC2 has input terminals IN1 and IN2, output terminals OUT1 and OUT2, and when an “H” level signal is input to the input terminal IN1 and an “L” level signal is input to the IN2, the output terminal OUT1 is output. When a signal of "L" level is generated at the input terminal IN1 and a signal of "H" level is input to the input terminal IN1, an "L" level signal is output to the output terminal OUT1. A "H" level signal is generated at OUT2.

In this drive circuit, the self-holding solenoid 1 is connected between the output terminals OUT1 and OUT2 of the bridge driver IC2, and the self-holding solenoid 1 is connected to the output terminal OUT1 of the bridge driver IC2 in the connection passage. A diode D and a resistor R are connected in parallel.

Next, the operation of this drive circuit will be described. When a control signal of "H" level is applied to the input terminal IN1 and "L" level is applied to IN2 as the first input condition, the bridge driver IC2 causes the output terminal OUT1 to output the "H" level signal and OUT2 to the "L" level signal. Cause As a result, a current flows through the path of the output terminal OUT1 → diode D → self-holding solenoid 1 → output terminal OUT2, and a pulse voltage (suction pulse voltage) of 12 V (Vcc) is applied to the self-holding solenoid 1. This causes the self-holding solenoid 1 to perform a suction operation.

When a control signal of “L” level is applied to the input terminal IN1 and “H” level is applied to IN2 as the second input condition, the bridge driver IC2 causes the output terminal OUT1 to be “L” level and OUT2 to be “H” level. Produces a level signal. As a result, a current flows through the path of the output terminal OUT 2 → the self-holding solenoid 1 → the resistor R → the output terminal OUT 1, and the self-holding solenoid 1 is applied with a pulse voltage (return pulse voltage) of 6 V (Vcc). This causes the self-holding solenoid 1 to return.

In this embodiment, the parallel connection circuit of the diode D and the resistor R is connected in the connection passage between the self-holding solenoid 1 and the output terminal OUT1, but the connection with the output terminal OUT2 is made. They may be connected in the passage, or the diode D may be connected in the opposite direction. Further, the load to be driven is not limited to the self-holding solenoid, but may be an actuator or the like used when opening and closing an automatic door (moves quickly when opening and moves slowly when closing).

[0014]

[Effect of device]

 As is apparent from the above description, according to the present invention, if the first output terminal of the drive circuit becomes the “H” level and the second output terminal becomes the “L” level according to the first input situation. , The first output terminal → diode (resistor) → load → second output terminal, the current flows, the first output terminal of the drive circuit is at the "L" level, the second output terminal according to the second input situation. When the output terminal of is at the “H” level, current flows through the route of the second output terminal → load → resistance (diode) → first output terminal, and the first input status and the second input status With this, different voltage values are applied to the load, and it becomes possible to drive a load such as a self-holding solenoid having different suction pulse voltage and return pulse voltage using the bridge driver IC.

[Brief description of drawings]

FIG. 1 is a diagram showing a drive circuit of a self-holding solenoid according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a drive circuit of a conventional self-holding solenoid.

[Explanation of symbols]

 1 Self-holding solenoid 2 Bridge driver IC IN1, IN2 Input terminal OUT1, OUT2 Output terminal D Diode R Resistance

Claims (1)

[Scope of utility model registration request] 1. A first output terminal is set to an “H” level and a second output terminal is set to an “L” level according to a first input situation,
A drive circuit that sets the first output terminal to the “L” level and the second output terminal to the “H” level according to the second input situation, and the first output terminal and the second output terminal of the drive circuit. And a load connected between the load and a first output terminal of the drive circuit, and a parallel connection circuit of a diode and a resistor connected in a connection path between the load and the first output terminal of the drive circuit. apparatus.