REVERSE POLARITY PROTECTION DEVICE

Abstract

A reverse polarity protection device includes a protection unit, a detection unit, and a control unit electrically connected between a power supply device and a load device. The detection unit is electrically connected to the power supply device for detecting the polarity of an output signal of the power supply device, and the control unit is electrically connected to the detection unit and the protection unit. The detection unit outputs a detection signal to the control unit according to a detection result of the polarity of the output signal. If the detection signal shows that the polarity of the output signal is reverse, the control unit will control the protection unit to form an open circuit between the power supply device and load device to stop transmitting the output signal of the power supply device to the load device and achieve a reverse polarity protection effect of the load device.

Claims

1. A reverse polarity protection device, comprising: a protection unit, electrically coupled between a power supply device and a load device; a detection unit, electrically coupled to the power supply device, for detecting the polarity of an output signal of the power supply device; and a control unit, electrically coupled to the detection unit and the protection unit; wherein if the detection unit detects that the polarity of the output signal is reverse, the control unit will control the protection unit to form an open circuit between the power supply device and the load device.

2. The reverse polarity protection device of claim 1, wherein the protection unit comprises an n-type MOSFET having a source terminal for receiving the output signal, and a drain terminal and a gate terminal respectively and electrically coupled to the load device and the control unit.

3. The reverse polarity protection device of claim 2, wherein the N-type MOSFET has a source terminal and a drain terminal electrically coupled to the control unit.

4. The reverse polarity protection device of claim 1, wherein the protection unit comprises a P-type MOSFET having a source terminal for receiving the output signal, and a drain terminal and a gate terminal respectively and electrically coupled to the load device and the control unit.

5. The reverse polarity protection device of claim 4, wherein the P-type MOSFET has a source terminal and a drain terminal electrically coupled to the control unit.

6. The reverse polarity protection device of claim 1, wherein the detection unit outputs a detection signal to the control unit, so that the control unit will control the protection unit to form a short circuit between the power supply device and the load device if the detection signal is a low level signal, and the control unit will control the protection unit to form an open circuit between the power supply device and the load device if the detection signal is a high level signal.

7. The reverse polarity protection device of claim 1, wherein the detection unit outputs a detection signal to the control unit, so that the control unit will control the protection unit to form a short circuit between the power supply device and the load device if the detection signal is a high level signal, and the control unit will control the protection unit to form an open circuit between the power supply device and the load device if the detection signal is a low level signal.

8. The reverse polarity protection device of claim 1, wherein the output signal is a voltage signal or a current signal.

9. The reverse polarity protection device of claim 1, wherein the load device is one selected from the group consisting of an industrial computer host, a server, a data center host, a desktop computer, a notebook computer, a tablet PC, a smartphone, and a smartwatch.

10. The reverse polarity protection device of claim 1, wherein the protection unit, the detection unit and the control unit are integrated into an integrated circuit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is a schematic circuit block diagram of a foolproof circuit structure as disclosed in R.O.C. Pat. No. M325665;

[0018] FIG. 2 is a schematic circuit block diagram of a reverse polarity protection device of the present invention;

[0019] FIG. 3 is a schematic circuit diagram of a reverse polarity protection device of the present invention;

[0020] FIG. 4 is a flow chart of a method of operating a detection unit and a control unit in accordance with the present invention; and

[0021] FIG. 5 is a schematic circuit diagram of a reverse polarity protection device of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] With reference to FIGS. 2 and 3 for a schematic circuit block diagram and a schematic circuit diagram of a reverse polarity protection device of the present invention respectively, the reverse polarity protection device 1 installed on a circuit comprises a protection unit 11, a detection unit 12 and a control unit 13. Wherein, the protection unit 11 is electrically coupled between a power supply device 2 and a load device 3, and the detection unit 12 is electrically coupled to the power supply device 2 for detecting the polarity of an output signal of the power supply device 2. On the other hand, the control unit 13 is electrically coupled to the detection unit 12 and the protection unit 11. In the present invention, the protection unit 11 comprises an N-type Metal-Oxide-Semiconductor Field-Effect Transistor (N-type MOSFET) QN. In FIG. 3, the N-type MOSFET QN has a source terminal (S) provided for receiving the output signal of the power supply device 2, and the N-type MOSFET QN has a drain terminal (D) and a gate terminal (G) respectively and electrically coupled to the load device 3 and the control unit 13. In addition, the N-type MOSFET QN has a source terminal (S) and a drain terminal (D) respectively and electrically coupled to the control unit 13. The control unit 13 also can self-detect the polarity of the output signal. For example, the control unit 13 compares an electric potential output signal of the source terminal (S) of the N-type MOSFET QN with the electric potential of a common ground to determine the polarity of the output signal. If the polarity of the output signal is correct, then the control unit 13 will drive the N-type MOSFET QN to form a short circuit between the power supply device 2 and the load device 3.

[0023] However, the power supply device 2 in a data center generally includes a multiple power output and OR-ing power structure (or a redundant power supply). To prevent the situation that if one of the power supply devices 2 is abnormal, then other power supplies will be affected, the present invention uses the detection unit 12 to notice the control unit 13 to turn on/off the N-type MOSFET QN.

[0024] According to the detection result of the polarity of the output signal, the detection unit 12 outputs a detection signal to the control unit 13 to drive the control unit 13 to turn on/off the N-type MOSFET QN. With reference to FIG. 4 for a flow chart of an operating method of a detection unit and a control unit in accordance with the present invention, after the power supply device 2 provides the output signal (step S1), if the detection unit 12 detects that the polarity of the output signal is normal (step S2), then the detection unit 12 will output the detection signal as a low level signal. The so-called normal polarity of the output signal refers to a potential of the output signal greater than zero. For example, if the output signal is a positive voltage signal or a positive current signal, then the detection unit 12 will compare the output signal with the electric potential of a common ground to determine that the potential level is greater than zero. In the step S3, the control unit 13 will turn on the N-type MOSFET QN if the detection signal is a low level signal, so that the protection unit 11 will form a short circuit between the power supply device 2 and the load device 3, and the output signal of the power supply device 2 will be transmitted to the load device 3.

[0025] On the contrary, if the detection result shows that the polarity of the output signal is reverse (step S2), the detection unit 12 will output the detection signal as a high level signal. In the step S4, the control unit 13 will turn off the N-type MOSFET QN if the detection signal is a high level signal, so that the protection unit 11 will form an open circuit between the power supply device 2 and the load device 3 to block and prevent the output signal of the power supply device 2 from being transmitted to the load device 3 continuously, so as to achieve a reverse polarity protection of the load device 3. It must be emphasized that the detection unit 12 will output a low level signal or a high level signal if the polarity of the output signal is normal or reverse respectively. It is noteworthy that it is not difficult for related engineers to design the detection unit 12 to output a high level signal or a low level signal when the polarity of the output signal is normal or reverse respectively.

[0026] Briefly, if one of the power supplies is abnormal or the polarity of the output signal is reverse, then the detection unit 12 will notice the control unit 13 directly to turn off the N-type MOSFET QN. Therefore, the design of the detection unit 12 provides an additional security mechanism. Even if one of the power outputs of the power supply device 2 is abnormal, the other power output will not be affected. It is noteworthy that the present invention is not limited to the load device 3 of this embodiment only, but any electronic device or electrical apparatus that requires an external power supply device such as an industrial computer host, a server, a data center host, a desktop computer, a notebook computer, a tablet PC, a smartphone, or a smartwatch may be used instead. On the other hand, the protection unit 11, the detection unit 12 and the control unit 13 may be integrated into an integrated circuit (IC) in an application.

[0027] Although FIG. 3 shows that the protection unit 11 includes an n-type MOSFET QN, yet the invention is not limited to the circuit of the protection unit 11 only. With reference to FIG. 5 for a schematic circuit diagram of a reverse polarity protection device of the present invention, the protection unit 11 may comprise a P-type MOSFET QP having a source terminal (S) for receiving the output signal of the power supply device 2, and a drain terminal (D) and a gate terminal (G) respectively and electrically coupled to the load device 3 and the control unit 13. In addition, the P-type MOSFET QN has a source terminal (S) and a drain terminal (D) electrically coupled to the control unit 13.

[0028] While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.