INDICATING CIRCUIT FOR INDICATING ROTATION SPEED OF A FAN AND ELECTRONIC DEVICE USING THE INDICATING CIRCUIT

摘要

An indicating circuit for indicating the rotation speed of a fan includes a rotation speed indicating module connected to the fan and receiving rotation speed signals from the fan. The indicating circuit includes a switch and a light emitting element. If the received signal is a high level signal, the switch is turned on, and the light emitting element emits light. If the reeived signal is a low level signal, the switch is turned off, and the light emitting element does not emit light.

主权项

1. An indicating circuit for indicating a rotation speed of a fan of an electronic device, the indicating circuit comprising:
a rotation indicating module connected to the fan via a connector, and the rotation indicating module receiving rotation speed signals from the fan via the connector, wherein the received rotation speed signals are pulse voltage signals, and the frequency of the rotation speed signals is in proportion to the rotation speed of the fan; the rotation indicating module comprising a light emitting element and a switch connected in series between a voltage supply terminal and ground; when a received rotation speed signal is a high level voltage signal, the switch is turned on, and the voltage supply terminal supply power to the light emitting element, thus the light emitting element emits light; and when a received rotation speed signal is a low level voltage signal, the switch is turned off, and the light emitting element does not emit light.