Method and circuit for driving piezoelectric motor

Abstract

The invention provides a method for driving a piezoelectric motor, which comprises the following steps: providing a direct current voltage; boosting the direct current voltage; and leading the boosteddirect current voltage to be used for controlling the piezoelectric motor. The invention also provides a circuit for driving the piezoelectric motor, which comprises a direct current power supply, adirect current converter, a switching element topological structure and a control module, wherein the direct current converter is used for boosting the direct current voltage output by the direct current power supply; the switching element topological structure is used for outputting the boosted direct current voltage to the piezoelectric motor in an alternating current way, and comprises a plurality of switching elements respectively connected to a sharing electrode and two discrete electrodes of the piezoelectric motor, and each switching element is provided with a control end; the control module is used for outputting PWM signals to the control ends of the switching elements so as to control the sharing electrode of the piezoelectric motor through the switching elements to form a circuit selectively together with the two discrete electrodes, thereby leading the piezoelectric motor to selectively move along one direction of two reverse directions. The invention simplifies the circuitby adopting less switching elements, thereby improving the reliability of the circuit and lowering the cost.

Description

【Technical field】 [0001] The invention relates to a piezoelectric motor driving method and circuit. 【Background technique】 [0002] Figure 6 Described is a prior art piezoelectric motor drive circuit diagram. The piezoelectric motor 10' can be used in cameras, cameras or video cameras, etc., and it includes a common electrode 14' and two separate electrodes 16', 18'. The drive circuit includes a DC power supply V1, a DC-AC converter connected to the DC power supply V1, and two LC oscillating circuits. DC to AC converters are used to convert DC voltage into AC voltage. The first oscillating circuit composed of inductor L1 and capacitor C1 connects the DC-AC converter to the common electrode 14' and the discrete electrode 16 of the piezoelectric motor, and the second oscillating circuit composed of inductor L2 and capacitor C2 connects the DC-AC converter to the piezoelectric motor. The electric motor has a common electrode 14' and a separate electrode 18', and the two osc...

AI Technical Summary

Problems solved by technology

[0003] In the above prior art, when the working environment of the piezoelectric motor 10' changes, the natural frequency of the piezoelectric motor 10' will change, so that the original quality factor of the oscillating circuit will no longer be different from that of the piezoelectric motor 10'. Therefore, a controller with a complex structure is required to adjust the frequency of the output voltage of the DC-AC converter so that the quality factor of the oscillating circuit best adapts to the changed natural frequency of the piezoelectric motor 10 ′, However, this will increase circuit cost

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