JPH0722997Y2 - Inductive load current drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an inductive load current drive device used for current driving an inductive load.

[Prior Art] FIG. 2 shows a configuration of a conventional inductive load current drive device.
In the figure, (1) is a variable current source, (2) is an internal resistance of the variable current source (1), and (3) is an inductive load.
The variable current source (1) is connected between both terminals (4) and (5) of the inductive load (3).

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

The variable current source (1) drives the inductive load (3).

[Problems to be Solved by the Invention] Since the conventional inductive load current drive device is configured as described above, when the inductive load has a specific mechanical resonance frequency, it resonates at that frequency. However, there is a problem that stable driving cannot be performed.

The present invention has been made to solve the above problems, and an object thereof is to provide an inductive load current drive device capable of stably driving an inductive load by suppressing resonance at a specific frequency. And

[Means for Solving the Problems] The inductive load current drive device according to the present invention is an LC series resonance circuit having a resonance frequency equal to the mechanical resonance frequency of the inductive load between both terminals of the inductive load. It is characterized by being connected.

[Action]

According to this invention, the inductive load and the LC series resonance circuit connected between both terminals thereof become a substantially parallel resonance circuit, and the current due to the back electromotive force generated by this parallel resonance circuit increases. However, since the LC series resonance circuit is in a short-circuited state, when viewed from the inductive load side, the coil of the LC series resonance circuit acts as a load, that is, an electromagnetic brake. Therefore, it is possible to reduce the impedance at the resonance point, absorb the counter electromotive force generated between both terminals of the inductive load, and attenuate only the mechanical resonance frequency motion generated in the inductive load. .

[Embodiment of the Invention] An embodiment of the invention will be described below with reference to the drawings.

FIG. 1 shows an example of an inductive load current drive device according to the present invention. The same parts as those of the conventional device are designated by the same reference numerals and the description thereof will be omitted. In the figure, (6) is a coil, and (7) is a capacitor. The coil (6) and the capacitor (7) are connected in series to each other and have a resonance equal to the mechanical resonance frequency of the inductive load (3). Have a frequency
It constitutes an LC series resonance circuit (8), and this LC series resonance circuit (8) has both terminals (4) and (5) of the inductive load (3).
Is connected in between.

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

The inductive load (3) is driven by the variable current source (1). When the inductive load (3) has a specific mechanical resonance frequency, the inductive load (3) vibrates at the mechanical resonance frequency different from the driving of the variable current source (1), and the inductive load (3) vibrates. A back electromotive force of a specific frequency appears between both ends (4) and (5) of (3).

Since the resonance frequency of the LC series resonance circuit (8) is equal to the mechanical resonance frequency of the inductive load (3), this LC
The coil (6) of the series resonant circuit (8) is
It acts as an electromagnetic brake, which lowers the counter electromotive force and damps only vibrations that are movements of the mechanical resonance frequency of the inductive load (3), and as a result, the inductive load (3). The drive is driven stably.

[Advantage of the Invention] As described above, according to the present invention, since the LC series resonance circuit is connected between both terminals of the inductive load, even if the inductive load has a specific mechanical resonance frequency, the It is possible to obtain an inductive load current drive device that can stably drive the inductive load without being driven.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing an example of an inductive load current driving device according to the present invention, and FIG. 2 is an electric circuit diagram showing a conventional inductive load current driving device. (1) ... Current source, (3) ... Inductive load, (4), (5)
… Terminal (8)… LC series resonant circuit. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] 1. An inductive load current drive device comprising an inductive load and a current source connected between both terminals of the inductive load to drive the load, wherein an inductive load current drive device is provided between both terminals of the inductive load. An inductive load current drive device, characterized in that an LC series resonance circuit having a resonance frequency equal to the mechanical resonance frequency of the inductive load is connected.