JPS6110818A - Drive circuit of electrostrictive actuator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a drive circuit for an electro-strain actuator.

<Background of the Invention> Electrostrictive actuators are attracting attention because they can easily realize relays that can open and close contacts with low power consumption.

On the other hand, in the case of relays, etc., it is common practice to use neon lamps etc. to indicate their operation, but if they are installed in a place where they cannot be seen visually, the visual display f stage such as the neon lamps is completely useless. Countermeasures to address this issue are awaited.

<First aspect of the invention> The present invention has been made in view of the circumstances described in -1-1f, and an object thereof is to provide a drive circuit for an electrostrictive actuator whose operation can be confirmed even if the actuator is located in a place where it cannot be seen. .

<Configuration and Effects of the Invention> In order to achieve the above objects, the drive circuit according to the present invention has the following features:
It is characterized in that an audible frequency alternating current is superimposed on a direct current and applied to the electrostrictive actuator.

By adopting the above configuration, the electrostrictive actuator is driven by the DC component, and at the same time, an audible sound is generated by the AC component. Therefore, even if it is not visible, the operation can be confirmed by hearing the audible sound as the operation sound.

<Description of Embodiment> An embodiment of the drive circuit according to the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, E is a DC power supply connected between a pair of input terminals I and 1, and OSC is an oscillation circuit that generates an audible frequency alternating current. This oscillation circuit O5C is composed of a blocking oscillator including, for example, an oscillation transformer T1), a bias resistor k of a transistor Q1, a feedback resistor R2, and a capacitor C□. D is a rectifying diode connected to the secondary side of the oscillation transformer T, P is an electrostrictive actuator, and R3 is a discharging resistor of the electrostrictive actuator P. The diode D and the image distortion actuator P constitute means for generating a direct current on which the alternating current from the oscillator O5C is superimposed. C2 is a bypass capacitor connected in parallel to both ends of the power supply E, and is used to smoothly operate the oscillator O5C. SW is a power switch.

Next, the operation of the above configuration will be explained.

When the power switch SW is closed (see Fig. 2 (A+)),
A DC voltage from power source E is input to blocking oscillator O5C. When capacitor C2 is charged and the base of transistor Q is positively biased, the transistor Q
1 of the oscillation transformer T becomes conductive and the collector current increases rapidly.
A pulsed current flows to the secondary side due to the induced voltage from the secondary side. That is, as the transistor Q becomes conductive, the capacitor C□ is discharged, so the transistor q becomes non-conductive, making it difficult for collector current to flow, and by repeating this, alternating current is generated on the secondary side of the oscillation transformer T. It is. This alternating current is set to emit an audible frequency, and this is due to the capacity of the capacitor C□ and the resistor R.
The resistance value of 2 and the oscillation transformer 1 are determined.

The alternating current having the above frequency is rectified by diode D.
It is half-wave rectified and applied to the electrostrictive actuator P, or since the electrostrictive actuator P itself is isometrically a capacitor, it acts as a smoothing effect. That is, as a result, the electrostrictive actuator P is driven by the DC voltage on which the audio frequency ripple V is superimposed, as shown in second [1(B)]. Therefore, the electrostrictive actuator P generates an audible sound in response to the AC component during its operation, and by using this as an operating sound, the operation can be confirmed even in a place where it cannot be seen. .

Furthermore, since the above-mentioned operation sound is emitted, it is also possible to use this as a substitute for an alarm such as a buzzer.

In addition, in the above embodiment, the alternating current component is superimposed during the entire period when the power switch SW is closed, or the timing can be arbitrarily selected, that is, the timing at which the operation sound of the electrostrictive actuator P is generated can be arbitrarily selected. Alternatively, the audible frequency can also be changed arbitrarily.

Furthermore, it goes without saying that the oscillation circuit O8C is not limited to a blocking oscillator.

As described above, the present invention drives an electrostrictive actuator with an audible frequency alternating current or a superimposed direct current voltage, so it is a convenient electrostrictive actuator whose operating state can be confirmed audibly even in a place where it cannot be seen. Therefore, it is possible to provide a drive circuit for the following.

[Brief explanation of the drawing]

FIG. 1C is a circuit diagram showing an embodiment of an electrostrictive actuator drive circuit according to the present invention, and FIG. 2(A) and FB+ are signal waveform diagrams for explaining the operation of the circuit. E...DC flL, D...diode, OSC...
Oscillation circuit, P...actuator, Q...transistor, C1...capacitor, T...oscillation transformer.

Claims (1)

[Claims] (1) Driving an electrostrictive actuator characterized by comprising an oscillation circuit that generates an alternating current of an audible frequency, and means for generating a direct current on which the alternating current from the oscillating circuit is superimposed and applying it to the electrostrictive actuator. circuit.