Command detection device

Abstract

This command detection device is equipped with a comparator, a detection state selector, a time detector, and a detection time switcher. The comparator compares a command input which has been input from the outside and a fixed voltage value, and outputs the comparison result as a first output state or a second output state. The detection state selector selects the output state to be enabled from the two output states output by the comparator. The time detector measures the duration of the enabled output state, and switches the control command when the duration reaches a specific set time. The detection time switcher switches the set time of the time detector. In addition, the output state selected and enabled by the detection state selector is switched by means of the control command.

Description

technical field [0001] The present invention relates to a command detection device for driving brushless DC motors used in information equipment such as air conditioners, combustion fan motor-mounted water heaters, air cleaners, copiers, and printers. Background technique [0002] Conventionally, there is a technique in which an analog voltage is applied when a control command is given to a brushless DC motor (hereinafter simply referred to as a motor), and the analog voltage value is converted into a magnitude of speed and torque as a control command. In addition, there is also a technique of comparing the analog voltage value with a fixed voltage value, and using the comparison result as a control command for switching the control state. Here, especially in the case of comparing an analog voltage value with a fixed voltage value, a comparator with hysteresis is used as the comparator of the voltage value to avoid the control command responding to an unintended minute fluct...

AI Technical Summary

Problems solved by technology

As a result, there are problems in that the input range that can be used for command input for other controls is narrowed or the command detection device cannot be used.

[0008] In addition, in the conventional system using resistors and capacitors, fluctuations in control commands caused by slight fluctuations in command input other than command inputs whose fluctuation time is approximately fixed, such as chattering generated at the time of switching, have become a problem.

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