Fan speed detection device

Abstract

The invention discloses a fan speed detection device including a metal sheet arranged on blades of a fan, an oscillating circuit module and a logic controller. The oscillating circuit module includesa first oscillating circuit, a second oscillating circuit and a signal processor. The first oscillating circuit includes a first capacitor and an induction ring disposed below vertical projection of blades of the fan. The second oscillating circuit includes a capacitor and a reference ring. The signal processor detects oscillating frequency of the first oscillating circuit and the second oscillating circuit in real time and outputs first oscillating frequency and second oscillating frequency to the logic controller. The logic controller outputs pulse signals according to a comparison result ofthe first oscillating frequency and the second oscillating frequency. The above device does not need to be equipped with a magnetic device and a built-in hall detection device and can realize real time detection of fan speed. The circuit structure is simple, motor material cost is reduced and the cost of a mini-size motor is reduced substantially.

Description

technical field [0001] The invention relates to the technical field of fan speed detection and speed regulation, in particular to a fan speed detection device. Background technique [0002] Now in the field of home appliance applications and industrial control, fans are more and more widely used, ranging from small cooling fans for CPUs to large mine exhaust fans. As a kind of equipment for gas compression and gas transportation, fans must occupy an important role for a considerable period of time. status. At present, the speed measurement and speed regulation schemes of fans on the market mainly use PG motors, which change the speed of fans by controlling the effective voltage. This design is currently widely used, but there are also shortcomings that cannot be solved by the industry: [0003] 1. For closed-loop output, an electronic device HALL detection board must be built into the motor [0004] 2. A magnetic device must be installed around the motor to trigger the hal...

AI Technical Summary

Problems solved by technology

At present, the speed measurement and speed regulation schemes of fans on the market mainly use PG motors, which change the speed of fans by controlling the effective voltage. This design is currently widely used, but there are also shortcomings that cannot be solved by the industry:

[0003] 1. For closed-loop output, an electronic device HALL detection board must be built into the motor

[0004] 2. A magnetic device must be installed around the motor to trigger the hall detection board

[0005] 3. The design of the motor is complex and the cost is high

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