Computer fan speed control device

• US 5,990,582 A
• Filed: 10/01/1997
• Issued: 11/23/1999
• Est. Priority Date: 05/13/1997
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micro Electronics Incorporated
• Inventors: Amdahl, Carlton G., Smith, Dennis H., Henderson, Michael G.
• Primary Examiner(s): Paladini, Albert W.
• Application Number:
  US08/942,447
• Time in Patent Office: 783 Days
• Field of Search: 307/116, 307/126, 307/130, 388/823, 388/840, 388/841, 236/DIG. 9
• US Class Current: 307/139
• CPC Class Codes: F04D 29/601 specially adapted for elastic fluid pumps
• CPC Class Codes: G06F 11/0748 in a remote unit communicating with a single-box computer node experiencing an error/fault remote testing G06F11/2294
• CPC Class Codes: G06F 11/0772 Means for error signaling, e.g. using interrupts, exception flags, dedicated error registers
• CPC Class Codes: G06F 11/0793 Remedial or corrective actions recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40
• CPC Class Codes: G06F 11/2294 by remote test
• CPC Class Codes: G06F 11/3058 Monitoring arrangements for monitoring environmental properties or parameters of the computing system or of the computing system component, e.g. monitoring of power, currents, temperature, humidity, position, vibrations thermal management in cooling arrangements of a computing system G06F1/206
• CPC Class Codes: G06F 11/328 Computer systems status display G06F11/327 takes precedence
• CPC Class Codes: G06F 11/3466 Performance evaluation by tracing or monitoring
• CPC Class Codes: G06F 11/3476 Data logging G06F11/14, G06F11/2205 take precedence
• CPC Class Codes: G06F 11/3495 for systems
• CPC Class Codes: G06F 13/4027 using bus bridges G06F13/4022 takes precedence
• CPC Class Codes: G06F 13/4081 Live connection to bus, e.g. hot-plugging current or voltage limitation during live insertion H02H9/004
• CPC Class Codes: G06F 21/305 by remotely controlling device operation
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06F 2201/86 Event-based monitoring
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 9/4411 Configuring for operating with peripheral devices; Loading of device drivers
• CPC Class Codes: H04L 12/12 Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: H04L 41/0213 Standardised network management protocols, e.g. simple network management protocol [SNMP]
• CPC Class Codes: H04L 41/12 : Discovery or management of network topologies
• CPC Class Codes: H04L 41/22 : comprising specially adapted graphical user interfaces [GUI]
• CPC Class Codes: H04L 49/90 : Buffering arrangements
• CPC Class Codes: H04L 67/1001 : for accessing one among a plurality of replicated servers
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A cooling system for cooling components of a computer is provided. The cooling system includes a DC fan which operates at a speed which is substantially proportional to the voltage that is applied to the fan. A zener diode voltage divider is connected in series between a voltage source and a first input of the fan. The second input of the fan is connected to a reference voltage source. A switch is also connected in series between the voltage source and the first voltage input of the fan so as to be connected in parallel with the zener diode voltage divider. When the switch is in a first position, the voltage produced by the voltage source is applied directly to the fan allowing the fan to operate at a first speed. When the switch is in a second position, the voltage from the voltage source is applied to the first input of the fan through the zener diode such that the first input of the fan receives a second voltage that is less than the first voltage thereby causing the fan to operate at a second speed. The zener diode voltage divider is substantially current independent such that the voltage drop across the zener diode is substantially independent of the current that is drawn by the fan.

Claims

1. A cooling apparatus for a computer comprising:

a first voltage source providing a first voltage;

a reference voltage source providing a reference voltage;

a fan having a first input and a second input wherein the fan operates at a speed that is related to a voltage that is applied between the first and the second inputs on the fan;

a zener diode voltage divider connected to the first voltage source and to the first input of the fan wherein the second input of the fan is connected to the reference voltage source; and

a switch having a first position and a second position, the switch being connected to the first input of the fan so that when the switch is in a first position, the fan directly receives a first voltage and operates at a first speed and the zener diode voltage divider is shorted and when the switch is in a second position that fan is connected to the first voltage source via the zener diode voltage divider such that the fan receives a second voltage directly from the zener diode voltage divider and operates at a second speed which is less than the first speed.

2. The cooling apparatus of claim 1, wherein the voltage divider is substantially current independent.

3. The cooling apparatus of claim 1, wherein the first voltage is approximately 12 Volts DC, the reference voltage is 0 volts DC and the change in magnitude between the first input voltage and the second input voltage is approximately 3 volts DC.

4. The cooling apparatus of claim 1, wherein the switch is comprised of an open collector gate, P-channel MOSFET that is connected in series between the first voltage source and the first input of the fan so as to be positioned in parallel with the voltage divider.

5. The cooling apparatus of claim 1, wherein the fan is a two wire DC fan that operates at a speed that is substantially proportional to the input voltage received by the fan.

6. A cooling apparatus for a computer comprising:

a voltage source providing a first voltage;

a fan having an input wherein the fan operates at a speed that is related to the voltage that is received by the fan;

a zener diode voltage divider that is connected to the voltage source and to the input of the fan; and

a switch connected to the fan and the voltage source so that when the switch is in a first position, the fan directly receives the first voltage and operates at a first speed and the zener diode voltage divider is shorted out and when the switch is in a second position the fan receives a second voltage directly from the zener diode voltage divider and operates at a second speed, wherein the first speed is less than the second speed.

7. The cooling apparatus of claim 6, wherein the first voltage is approximately 12 Volts DC, the reference voltage is 0 volts DC and the change in magnitude between the first input voltage and the second input voltage is approximately 3 volts DC.

8. The cooling apparatus of claim 6, wherein the switch is connected in series between the voltage source and the input of the fan so as to be positioned in parallel with the voltage divider.

9. The cooling apparatus of claim 8, wherein the switch is comprised of an open collector gate, P-channel MOSFET.

10. The cooling apparatus of claim 9, wherein the fan is a two wire DC fan that operates at a speed that is substantially proportional to the input voltage received by the fan.

11. A cooling apparatus for a computer comprising:

a voltage source providing a first voltage;

a fan having an input which is adapted to be mounted in a computer wherein the fan operates at a speed that is related to the voltage that is received by the fan;

a zener diode divider that is connected to the voltage source and to the input of the fan; and

a switch connected to the fan and the voltage source so that when the switch is in a first position, the fan directly receives the first input voltage and operates at a first speed and when the switch is in a second position the fan receives a second input voltage directly from the zener diode divider and operates at a second speed, wherein the first speed is less than the second speed wherein the switch is coupled to the zener diode voltage divider so that only one of the first and second voltages is enabled at one time.

12. The cooling apparatus of claim 11, wherein the first voltage is approximately 12 Volts DC, the reference voltage is 0 volts DC and the change in magnitude between the first input voltage and the second input voltage is approximately 3 volts DC.

13. The cooling apparatus of claim 11, wherein the switch is connected in series between the first voltage source and the input of the fan so as to be positioned in parallel with the voltage divider.

14. The cooling apparatus of claim 13, wherein the switch is comprised of an open collector gate, P-channel MOSFET.

15. The cooling apparatus of claim 14, wherein the fan is a two wire DC fan that operates at a speed that is substantially proportional to the input voltage received by the fan.

16. A cooling apparatus for a computer comprising:

a first voltage source providing a first voltage;

a reference voltage source providing a reference voltage;

a fan having a first input and a second input which are adapted to be mounted in a computer wherein the fan operates at a speed that is substantially proportional to the voltage that is applied between the first and the second inputs on the fan;

a zener diode voltage divider connected to the first voltage source and to the first input of the fan wherein the second input of the fan is connected to the reference voltage source; and

a switch connected to the first input of the fan and to the first voltage source so as to be connected in parallel with the zener diode voltage divider so that when the switch is closed, the switch directly applies the first voltage to the first input of the fan and when the switch is open, the first input of the fan receives a second voltage that is less than the first voltage from the zener diode voltage divider such that the speed of operation of the fan upon receiving the second voltage is less than the speed of operation of the fan receiving the first voltage, wherein the fan receives only one of the first and second voltages in the first and second positions of the switch.

17. The cooling apparatus of claim 16, wherein the first voltage is approximately 12 volts DC, the reference voltage is approximately 0 volts DC and the change in magnitude between the first voltage and the second voltage is approximately 3 volts DC.

18. The cooling apparatus of claim 17, wherein the switch is comprised of an open collector gate, P-channel MOSFET that is connected in series between the first voltage source and the first input of the fan so as to be positioned in parallel with the voltage divider.

19. The cooling apparatus of claim 18, wherein the fan is a two wire DC fan.