Apparatus for controlling cooling device and cooling system
A cooling device controller for controlling a cooling device is provided. The cooling device controller includes: a capacitor for supplying an output voltage through a first terminal; a first switch between a first input terminal and the first terminal of the capacitor; a predetermined reference voltage applied to the first input terminal; a second switch between a second input terminal and the first terminal of the capacitor, wherein a temperature-sensing voltage is applied to the second input terminal, the temperature-sensing voltage varying according to a first sensed temperature; and a switch controller to receive a first voltage waveform having a duty ratio, the duty ratio dependent on a second sensed temperature, wherein the switch controller is operable to turn on and off the first switch and the second switch according to the duty ratio.
1. A cooling device controller for controlling a cooling device for reducing a temperature of a system, the cooling device controller comprising:
a capacitor coupled to an output terminal for supplying an output voltage that depends on temperature;
a first switch between a first input terminal and the output terminal, wherein a predetermined reference voltage is applied to the first input terminal and the capacitor is charged or discharged at the output terminal by the predetermined reference voltage when the first switch is turned on;
a second switch between a second input terminal and the output terminal, wherein a temperature-sensing voltage is applied to the second input terminal and the capacitor is charged or discharged at the output terminal by the temperature-sensing voltage when the second switch is turned on, the temperature-sensing voltage varying according to information for a first sensed temperature; and
a switch controller, operable to receive a first voltage waveform having a pulse width modulation with a duty ratio, the duty ratio dependent on information for a second sensed temperature,
wherein the switch controller is operable to turn on and off the first switch and the second switch based on the first voltage waveform to generate the output voltage that depends on the predetermined reference voltage and the temperature-sensing voltage according to the duty ratio.
2. The cooling device controller of claim 1 , wherein
the switch controller turns on the first switch when the first voltage waveform assumes a first voltage value and turns on the second switch when the first voltage waveform assumes a second voltage value.
3. The cooling device controller of claim 2 , wherein
the duty ratio of the first voltage waveform increases when the second sensed temperature is greater than a reference temperature for stabilizing the system.
4. The cooling device controller of claim 3 , wherein
the temperature-sensing voltage at the second input terminal decreases as the temperature increases, and the maximum of the temperature-sensing voltage is less than the reference voltage.
5. The cooling device controller of claim 3 , wherein
the temperature-sensing voltage at the second input terminal decreases as the temperature increases, and the minimum of the temperature-sensing voltage is greater than the reference voltage.
6. The cooling device controller of claim 5 , wherein
the predetermined reference voltage is a voltage level that corresponds to a ground voltage.
7. The cooling device controller of claim 6 , wherein
the temperature-sensing voltage is applied by a circuit including a thermistor.
8. The cooling device controller of claim 7 , further comprising a buffer for maintaining a buffer voltage level of the temperature-sensing voltage.
9. The cooling device controller of claim 6 , wherein
the output voltage is utilized for controlling the cooling device.
10. The cooling device controller of claim 1 , further comprising at least one of:
a first resistor coupled in series with the first switch between the first input terminal and a first terminal of the capacitor; and
a second resistor coupled in series with the second switch between the second input terminal and the first terminal of the capacitor.
11. The cooling device controller of claim 1 , wherein at least one of the information for the first sensed temperature and the information for the second sensed temperature varies non-linearly with temperature.