DC MOTOR AUTO LIFT

Abstract

A DC motor drive comprises an AC to DC exchange system, a circuit protection system and a motor start system connected to a DC motor. The AC to DC exchange system is connected to an AC power supply and is configured to convert AC power to DC power. The circuit protection system is connected to the AC to DC exchange system. The circuit protection system includes a resistor connected in series with a diode. The motor start system includes a first switch and a second switch. The first switch is connected across the DC motor and the second switch connected in series with the DC motor. When the AC supply is applied to the DC motor drive of the auto lift, the AC to DC exchange system converts the AC power to DC power which starts the DC motor by means of the motor start system.

Claims

1. A DC motor drive for an auto lift, comprising: an AC to DC exchange system connected to an AC power supply and configured to convert AC power to DC power, a circuit protection system having a resistor connected in series with a diode; and a motor start system connected to a DC motor of the auto lift, the motor start system having a first switch and a second switch; whereby the AC to DC exchange system converts the AC power to DC power which starts the DC motor by means of the motor start system and enables the DC motor to operate the auto lift.

2. The DC motor drive of claim 1 wherein the AC power supply is a single phase power supply.

3. The DC motor drive of claim 1 wherein the AC power supply is a three phase power supply.

4. The DC motor drive of claim 1 wherein the AC to DC exchange system is a single phase full wave bridge rectifier.

5. The DC motor drive of claim 1 wherein the AC to DC exchange system is a three phase full wave bridge rectifier.

6. The DC motor drive of claim 1 wherein the circuit protection system protects the DC motor from high currents.

7. The DC motor drive of claim 1 wherein the resistor is a 10 3 W resistor.

8. The DC motor drive of claim 1 wherein the diode is a 6 A 1 kV diode.

9. The DC motor drive of claim 1 wherein the first switch is connected across the DC motor and the second switch is connected in series with the DC motor.

10. The DC motor drive of claim 1 wherein the first switch is a normally open switch.

11. The DC motor drive of claim 1 wherein the second switch is a double pole single throw switch.

12. The DC motor drive of claim 1 wherein the second switch is connected between the circuit protection system and the DC motor.

13. The DC motor drive of claim 1 wherein the second switch is used to start the DC motor.

14. The DC motor drive of claim 1 wherein the AC to DC exchange system provides good starting characteristics and speed regulation characteristics for the DC motor.

15. The DC motor drive of claim 1 wherein the torque of the DC motor is relatively large and has high speed regulation efficiency to achieve smooth and economical speed adjustments.

16. A DC motor drive for an auto lift, comprising: an AC to DC exchange system connected to an AC power supply, the AC to DC exchange system configured to convert AC power to DC power, a circuit protection system connected to the AC to DC exchange system, the circuit protection system having a resistor connected in series with a diode; and a motor start system connected to a DC motor of the auto lift, the motor start system having a first switch and a second switch, the first switch connected across the DC motor and the second switch connected in series with the DC motor; whereby the AC to DC exchange system converts the AC power to DC power which starts the DC motor by means of the motor start system and enables the DC motor to operate the auto lift.

17. The DC motor drive of claim 16 wherein the AC power supply is a single phase power supply.

18. The DC motor drive of claim 16 wherein the AC power supply, is a three phase power supply.

19. The DC motor drive of claim 16 wherein the AC to DC exchange system is a single phase full wave bridge rectifier.

20. The DC motor drive of claim 16 wherein the AC to DC exchange system is a three phase full wave bridge rectifier.

21. The DC motor drive of claim 16 wherein the circuit protection system protects the DC motor from high currents.

22. The DC motor drive of claim 16 wherein the resistor is a 10 3 W resistor.

23. The DC motor drive of claim 16 wherein the diode is a 6 A 1 kV diode.

24. The DC motor drive of claim 16 wherein the first switch is a normally open switch.

25. The DC motor drive of claim 16 wherein the second switch is a double pole single throw switch.

26. The DC motor drive of claim 16 wherein the second switch is connected between the circuit protection system and the DC motor.

27. The DC motor drive of claim 16 wherein the second switch is used to start the DC motor.

28. The DC motor drive of claim 16 wherein the AC to DC exchange system provides good starting characteristics and speed regulation characteristics for the DC motor.

29. The DC motor drive of claim 16 wherein the torque of the DC motor is relatively large and has high speed regulation efficiency to achieve smooth and economical speed adjustments.

30. A method for operating an auto lift utilizing a DC motor drive, the method comprising the steps of: a) providing the DC motor drive having an AC to DC exchange system, a circuit protection system and a motor start system; b) applying an AC power to the AC to DC exchange system; c) converting AC power to DC power by the AC to DC exchange system; d) providing the generated DC power to the circuit protection system; e) applying the DC power to the motor start system from the circuit protection system; and f) starting the DC motor to operate the auto lift by the motor start system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Elements in the figures have not necessarily been drawn to scale in order to enhance their clarity and improve understanding of these various elements and embodiments of the invention. Furthermore, elements that are known to be common and well understood to those in the industry are not depicted in order to provide a clear view of the various embodiments of the invention, thus the drawings are generalized in form in the interest of clarity and conciseness.

[0019] FIG. 1 illustrates a block diagram of a DC motor drive for operating an auto lift in accordance with the preferred embodiment of the present invention;

[0020] FIG. 2 illustrates a circuit diagram of a single phase DC motor drive for operating the auto lift in accordance with the preferred embodiment of the present invention;

[0021] FIG. 3 illustrates a circuit diagram of a three phase DC motor drive for operating the auto lift in accordance with one embodiment of the present invention; and

[0022] FIG. 4 illustrates a flowchart of a method for operating the auto lift utilizing the DC motor drive in accordance with the preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0023] In the following discussion that addresses a number of embodiments and applications of the present invention, reference is made to the accompanying drawings that form a part hereof and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and changes may be made without departing from the scope of the present invention.

[0024] Various inventive features are described below that can each be used independently of one another or in combination with other features. However, any single inventive feature may not address any of the problems discussed above or only address one of the problems discussed above. Further, one or more of the problems discussed above may not be fully addressed by any of the features described below.

[0025] As used herein, the singular forms a, an and the include plural referents unless the context clearly dictates otherwise. And as used herein is interchangeably used with or unless expressly stated otherwise. As used herein, the term about means+/5% of the recited parameter. All embodiments of any aspect of the invention can be used in combination, unless the context clearly dictates otherwise.

[0026] Unless the context clearly requires otherwise, throughout the description and the claims, the words comprise, comprising, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of including, but not limited to. Words using the singular or plural number also include the plural and singular number, respectively. Additionally, the words herein, wherein, whereas, above, and below and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of the application.

[0027] The description of embodiments of the disclosure is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. While the specific embodiments of and examples for, the disclosure are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize.

[0028] Referring to FIG. 1, a block diagram of a DC motor drive 100 for operating an auto lift in accordance with the preferred embodiment of the present invention is illustrated. The DC motor drive 100 of present invention uses an AC electrical power supply 102 which is converted to DC power internally which is used by a DC motor 110 to power the auto lift. The present invention provides immediate high torque than a conventional AC powered auto lift and has the ability to run on either AC or DC power. The DC motor drive 100 can be used as a single phase DC motor drive 124 (see FIG. 2) and a three phase DC motor drive 126 (see FIG. 3). The DC motor drive 100 comprises an AC to DC exchange system 104, a circuit protection system 106 and a motor start system 108 connected to the DC motor 110. The AC to DC exchange system 104 is connected to the AC power supply 102. The AC power supply 102 can be a single phase power supply (see FIG. 2) or a three phase power supply (see FIG. 3). The AC to DC exchange system 104 is configured to convert AC power to DC power. The circuit protection system 106 is connected to the AC to DC exchange system 104. The circuit protection system 106 includes a resistor 112 connected in series with a diode 114. The motor start system 108 is connected to the DC motor 110 of the auto lift. The motor start system 108 includes a first switch 120 and a second switch 122. The first switch 120 is connected across the DC motor 110 and the second switch 122 is connected in series with the DC motor 110.

[0029] FIGS. 2 and 3 illustrate a circuit diagram of a single phase DC motor drive 124 and a three phase DC motor drive 126 respectively for operating the auto lift. The AC to DC exchange system 104 is connected to the AC power supply 102 and is configured to convert AC power to DC power. The AC to DC exchange system 104 is a single phase full wave bridge rectifier 116 for the single phase DC motor drive 124 and it is a three phase full wave bridge rectifier 118 for the three phase DC motor drive 126. The circuit protection system 106 connected to the AC to DC exchange system 104 protects the DC motor 110 from high currents. The circuit protection system 106 includes the resistor 112 connected in series with the diode 114. The resistor 112 is a 10 3 W resistor and the diode 114 is a 6 A 1 kV diode. In some embodiments, the resistor 112 can have a resistance varying from 5.1 to 10 and 10 W. In some embodiments, the diode 114 ratings can range from 6 A to 10 A and voltage ranging from 1 KV to 2 KV. The motor start system 108 is connected to the DC motor 110 of the auto lift. The motor start system 108 includes the first switch 120 and the second switch 122. The first switch 120 is connected across the is DC motor 110 and the second switch 122 is connected in series with the DC motor 110. The first switch 120 can preferably be a normally open switch and the second switch 122 is a double pole single throw switch. The second switch 122 is connected between the circuit protection system 106 and the DC motor 110. The second switch 122 is used to start the DC motor 110. When the AC supply 102 is applied to the DC motor drive 100 of the auto lift, the AC to DC exchange system 104 converts the AC power to DC power which starts the DC motor 110 by means of the motor start system 108. The DC motor 110 thus started operates the auto lift. The AC to DC exchange system 104 of the present invention provides good starting characteristics and speed regulation characteristics for the DC motor 110. The torque of the DC motor 110 is relatively large and has high speed a regulation efficiency to achieve smooth and economical speed adjustments.

[0030] FIG. 4 illustrates a flowchart of a method for operating the auto lift utilizing the DC motor drive in accordance with the preferred embodiment of the present invention. The method comprising the steps of: providing the DC motor drive having an AC to DC exchange system, a circuit protection system and a motor start system as indicated in block 202. Applying an AC power to the AC to DC exchange system as indicated in block 204. Then converting AC power to DC power by the AC to DC exchange system as indicated in block 206. Providing the generated DC power to the circuit protection system as indicated in block 208 and applying the DC power to the motor start system from the circuit protection system as indicated in block 210. Starting the DC motor to operate the auto lift by the motor start system as indicated in block 212.

[0031] The DC motor drive 100 of the present invention uses AC electrical power 102 from the single phase or three phase supply and converts it into DC power internally in the motor 110 which is used to operate the auto lift. The DC motor drive 100 provides more immediate high torque than any conventional AC motor used in the auto lifts and has the ability to operate using either AC power or DC power. In one embodiment, additional storage unit and safety devices are provided in case of a power failure. The DC motor drive 100 is primarily used in auto lifts. The present DC motor drive 100 can also be utilized in aircraft hangar door lifts and similar applications.

[0032] The DC motor drive 100 of the present invention provides good starting characteristics and speed regulation characteristics. The torque of the DC motor is relatively large which enables smooth and economical speed adjustment of the motor 110 to operate the auto lift, and does not require any additional starting equipment to start the as motor 110. Thus the present invention replaces the AC current motor used in auto repair lifts with the DC motor 110 which has more torque and has the ability to move the load faster. The DC motor drive 100 is more energy-saving and environmentally friendly and maintenance is relatively cheap. With the addition of switching devices such as the first switch 120 and the second switch 122, the inherent advantages of high efficiency and compactness of the DC motor 110 is re-integrated into efficient, compact, stable, controllable and cheap power source.

[0033] The foregoing description of the preferred embodiment of the present invention has been presented for the purpose of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teachings. It is intended that the scope of the present invention not be limited by this detailed description, but by the claims and the equivalents to the claims appended hereto.