JPS6249966B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic solenoid drive device that applies a current to an electromagnetic coil and uses its magnetomotive force to attract a magnetic body such as a piece of iron, and improves the rise characteristics of the current flowing through the electromagnetic coil. The aim is to improve responsiveness by doing so.

Figure 1 shows a conventionally commonly used electromagnetic solenoid drive circuit, where 1 indicates a drive power source;
2 is a power solenoid electromagnetic coil, 3 is a mechanical switch such as a relay, 4 is a flywheel diode, and 5 is a device that suppresses the back electromotive force generated in the electromagnetic coil 2 when the switch 3 is turned off, and at the same time quickly reduces the current to zero. represents an element or circuit (hereinafter referred to as a circuit) for

In the above configuration, when the switch 3 is closed, a current having a rising characteristic corresponding to the time constant flows through the electromagnetic coil 2, resulting in a steady current.

When the switch 3 is opened from this state, the flywheel current of the electromagnetic coil 2 flows through the diode 4 to the circuit 5 and falls with a time constant determined by the impedance of the electromagnetic coil 2 and the constant of the circuit 5.

The responsiveness of an electromagnetic solenoid is not only affected by the mechanical time constant of the moving part, but also by the responsiveness of the magnetomotive force of the electromagnetic coil, that is, the rise and fall characteristics of the current flowing through the electromagnetic coil. In the conventional drive circuit shown in Figure 1, the time constant of the electromagnetic coil is a factor that determines the rise and fall characteristics of the current, and even the response of the electromagnetic solenoid. was.

This is a particular problem in electromagnetic solenoids that require a relatively large output and also require high responsiveness.

The present invention provides a drive device for improving the above-mentioned conventional drawbacks, and an embodiment thereof will be described below with reference to FIG. 2.

In Fig. 2, 1 is a driving power source, 2 is an electromagnetic coil which is an electromagnetic solenoid, 3 is a second switch connected to one end of the electromagnetic coil 2, 4 is a flywheel diode, and 5 is a voltage charged to a capacitor 7. This element is connected in parallel to the electromagnetic coil 2 via the flywheel diode 4. 6 is a first switch connected to the electromagnetic coil 2 via a first diode 8; one end of 7 is connected to the connection point between the first diode 8 and the first switch 6; This is a capacitor connected to the connection point between the other end of the first diode 8 and the electromagnetic coil 2 . A second diode 9 is connected between the other end of the capacitor 8 and the other end of the first switch 6.

In the above configuration, if the driving electromagnetic 1 is applied with the switches 3 and 6 open, the capacitor 7 will be connected to the electromagnetic coil 2, the diode 8,
A current flows through the diode 9, and the diode 9 is charged with a voltage substantially close to the driving power supply voltage.

When switch 3 and switch 6 are closed in this state, diode 8 and diode 9 are reverse biased and turn off, and as a result, the electromagnetic coil 2 has a form in which the voltages of the driving power supply 1 and the capacitor 7 are added. Join with.

Therefore, a voltage approximately twice as high as the voltage of the driving power source 1 is initially applied to the electromagnetic coil 2, and the current rise characteristics are improved accordingly.

In a steady state, current flows through switch 3 and diode 9 or diode 8 and switch 6.

In this state, if switch 3 and switch 6 are opened, the flywheel current of electromagnetic coil 2 will flow into capacitor 7 if element 5 is not connected, and if element 5 is connected,
Depending on the constant of the element 5, the current flows into the element 5 and the capacitor 7 in a divided manner.

At this time, the capacitor 7 is charged to a voltage determined by the voltage of the driving power source 1, the inductance of the electromagnetic coil 2, the conductance of the capacitor 7, and the constant of the element 5.

Next time, when switches 3 and 6 are closed, the voltages of the driving power supply 1 and the capacitor 7 are added to the electromagnetic coil 2 according to the same operation as described above, and the voltage of the capacitor 7 is equal to its conductance. Since it is possible to make the voltage high by appropriately selecting the voltage, the rise characteristic of the current flowing through the electromagnetic coil 2 can be made sharp accordingly.

After that, repeat the above operation.

FIG. 3 shows an example in which switch 3 and switch 6 in FIG. 2 are configured with transistors, and element 5, which is a shunt circuit for the flywheel current, is omitted. 1 is a driving power source, and 2 is an electromagnetic solenoid. , 3 and 6 are transistors for switching, 7 is a capacitor, 8 and 9 are diodes, and 10 is a resistor for flowing current to the base of transistor 3.

In the above configuration, if the drive power supply 1 is applied to the base of the transistor 6 with no drive signal input, both the transistor 3 and the transistor 6 are in the OFF state, so the capacitor 7
A current flows through the electromagnetic coil 2, diode 8, and diode 9.

At this time, the capacitor 7 is finally connected to the driving power supply 1.
The battery will be charged at a voltage close to that of .

If a driving signal is applied to the base of the transistor 6 in this state, the transistor 6 becomes conductive and the emitter of the transistor 3 becomes a negative potential corresponding to the voltage of the capacitor 7.

As a result, the base of transistor 3 has a resistor 1
Current flows through 0, and transistor 3 also flows at the same time.
It becomes ON state.

This is the same state as in FIG. 2 when switch 3 and switch 6 are both closed, so electromagnetic solenoid 2 is connected to driving power source 1 and capacitor 7.
The voltages are added together, and the current rise characteristics of the electromagnetic solenoid 2 are improved accordingly.

In steady state, current flows through diode 8 and transistor 6.

When the base current of the transistor 6 is cut off, the current that has been flowing through the electromagnetic coil 2 flows into the capacitor 7 through the diode 8 and the diode 9, and becomes zero with a time constant corresponding to the constants of the electromagnetic coil 2 and the capacitor 7. , the capacitor 7 is also charged to a high voltage according to these constants.

The next time a drive signal is applied to the transistor 6, it will perform the same operation as described above, and the voltages of the drive power source 1 and the capacitor 7 will be added to the electromagnetic coil 2, changing the current rise characteristics of the electromagnetic coil 2. It can be made sufficiently sharp.

As described above, according to the present invention, it is possible to improve the current rise characteristics of the electromagnetic coil with a simple circuit configuration without making any changes to the drive power source, etc., and accordingly, the rise characteristics of the electromagnetic coil current can be improved. Responsiveness can also be improved.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventional electromagnetic solenoid drive device, FIG. 2 is a circuit diagram of an electromagnetic solenoid drive device according to an embodiment of the present invention, and FIG. 3 is a circuit diagram of another embodiment of the present invention. be. DESCRIPTION OF SYMBOLS 1... Drive power supply, 2... Electromagnetic solenoid (electromagnetic coil), 3... Second switch, 6... First switch, 7... Capacitor, 8... First diode, 9... Second diode.

Claims (1)

[Scope of Claims] 1. A first switch that supplies current from a driving power source to an electromagnetic solenoid via a first diode, one end of which is connected to a connection point between the first diode and the first switch, and the other end of which is connected to a connection point between the first diode and the first switch. a capacitor connected to the other end of the first diode and the connection point of the electromagnetic solenoid via a second switch; and a second diode connected between the other end of the capacitor and the other end of the first switch. An electromagnetic solenoid drive device characterized by: 2. The electromagnetic solenoid drive device according to claim 1, wherein the first and second switches are constructed of transistors.