CPC H05K 7/20209 (2013.01) [F04D 27/004 (2013.01); F04D 27/008 (2013.01); G06F 1/3206 (2013.01)] | 10 Claims |
1. A fan control device with power saving mode and startup setting, comprising:
a control chip, the control chip at least including:
a main control circuit configured to control a speed of the fan through receiving an external voltage level, the external voltage level determined by an external voltage divider coupled to a power source;
a protection control module configured to receive an input voltage corresponding to ambient temperature for sending an alarm signal to the main control circuit while a detected ambient temperature being higher than a preset temperature; and
a sleep mode control module electrically coupled to an externally adjustable voltage threshold circuit, the externally adjustable voltage threshold circuit comprising the power source, a first resistor with one end of the first resistor coupled to the power source, a second resistor with one end of the second resistor coupled in series to the other end of the first resistor, a ground coupled to the other end of the second resistor, and a capacitor being configured to coupled in parallel to the first resistor;
wherein the sleep mode control module compares an input voltage threshold from the externally adjustable voltage threshold circuit and the input voltage detected by the protection control module, and sends a control signal to the main control circuit depended on comparing results of the sleep mode control module for controlling operation modes of the fan.
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