Control circuit for a brake unit

Abstract

The utility model provides a control circuit which is applied to a brake unit. The circuit comprises a first voltage detection unit, a second voltage detection unit, a first comparison unit, a shunt, a second comparison unit, a first logic gate circuit and a PWM signal generation unit, and the two input ends of the first comparison unit are electrically connected to the output end of the first voltage detection unit and a first reference voltage respectively. The two detection ends of the second voltage detection unit are electrically connected to the two output ends of the shunt respectively, the two input ends of the second comparison unit are electrically connected to the output end of the second voltage detection unit and a second reference voltage respectively, and the first input end and the second input end of the first logic gate circuit are electrically connected to the output ends of the first comparison unit and the second comparison unit respectively. The first logic gate circuit is configured to output high level if the two paths of input signals are both high level and output low level if any path of input signal is low level, and the enabling end of the PWM signal generation unit is electrically connected to the output end of the first logic gate circuit.

Description

Technical Field

[0001] The utility model relates to the field of a brake unit and control thereof, in particular to a control circuit for a brake unit. Background Art

[0002] The existing control system of the brake unit mainly adopts a design scheme combining a main control chip and a transceiver module, which has high design cost, software maintenance cost and material cost. A control scheme that can meet the low-cost needs of users is urgently needed. Utility Model Content

[0003] In view of the above problems in the prior art, the utility model proposes a new control circuit. The new control circuit does not need to use a special communication module and CU controller chip, has a simple design, and greatly reduces the design cost and material cost.

[0004] The utility model provides a control circuit applied to a brake unit, the control circuit comprising:

[0005] a first voltage detection unit and a first comparison unit, wherein a first input terminal of the first comparison unit is electrically connected to an output terminal of the first voltage detection unit and a second input terminal is electrically connected to a first reference voltage, and the first comparison unit is configured to output a high level if a voltage at the first input terminal is greater than the first reference voltage;

[0006] a current divider, a second voltage detection unit and a second comparison unit, wherein two detection terminals of the second voltage detection unit are electrically connected to two output terminals of the current divider, respectively, a first input terminal of the second comparison unit is electrically connected to the output terminal of the second voltage detection unit and a second input terminal is electrically connected to a second reference voltage, and the second comparison unit is configured to output a high level if the voltage of the first input terminal is greater than the second reference voltage;

[0007] a first logic gate circuit, wherein a first input terminal of the first logic gate circuit is electrically connected to an output terminal of the first comparison unit and a second input terminal of the first logic gate circuit is electrically connected to an output terminal of the second comparison unit, and the first logic gate circuit is configured to output a high level if both input signals are high level and to output a low level if any input signal is low level;

[0008] A PWM signal generating unit, wherein an enable terminal of the PWM signal generating unit is electrically connected to the output terminal of the first logic gate circuit, and the PWM signal generating unit is configured to generate a PWM signal if the enable terminal input is at a high level.

[0009] According to one embodiment of the utility model, in the above-mentioned control circuit, the two detection ends of the first voltage detection unit are respectively electrically connected to the positive and negative poles of the external DC bus voltage connected to the braking circuit, the shunt is electrically connected in series in the external braking circuit, and the output end of the PWM signal generating unit is electrically connected to the IGBT drive unit in the external braking circuit.

[0010] According to an embodiment of the present utility model, in the above control circuit, the control circuit further includes a second logic gate circuit;

[0011] The first input end of the second logic gate circuit is electrically connected to the output end of the second comparison unit, the second input end is electrically connected to the fault feedback end of the IGBT drive unit in the external braking circuit, and the output end is electrically connected to the second input end of the first logic gate circuit. The second logic gate circuit is configured to output a low level if the signal of any input is a high level, and to output a high level if the signal of each input is a low level.

[0012] According to an embodiment of the present utility model, in the above control circuit, the control circuit further includes a temperature detection unit and a third comparison unit;

[0013] The temperature detection unit is connected to a heat dissipation unit connected to the IGBT in an external braking circuit, the output end of the temperature detection unit is electrically connected to the first input end of the third comparison unit, the second input end of the third comparison unit is electrically connected to a third reference voltage and the output end is electrically connected to the third input end of the second logic gate circuit, and the third comparison unit outputs a high level when the voltage of the first input end is greater than the third reference voltage.

[0014] According to an embodiment of the utility model, in the above control circuit, the control circuit further includes a heat dissipation unit, a temperature detection unit and a third comparison unit;

[0015] The temperature detection unit is connected to the heat dissipation unit, the heat dissipation unit is connected to the IGBT in the external brake circuit, the output end of the temperature detection unit is electrically connected to the first input end of the third comparison unit, the second input end of the third comparison unit is electrically connected to the third reference voltage and the output end is electrically connected to the third input end of the second logic gate circuit.

[0016] According to an embodiment of the present utility model, in the above-mentioned control circuit, the control circuit further includes a fourth comparison unit, a first drive unit and a fan;

[0017] The first input terminal of the fourth comparison unit is electrically connected to the output terminal of the temperature detection unit and the second input terminal is electrically connected to a fourth reference voltage, the fourth reference voltage is less than the third reference voltage, the first driving unit is electrically connected between the output terminal of the fourth comparison unit and the enable terminal of the fan, and the fourth comparison unit is configured to output a high level if the voltage of the first input terminal is greater than the fourth reference voltage.

[0018] According to an embodiment of the present utility model, in the above-mentioned control circuit, the control circuit further includes a second driving unit and a first indicator light;

[0019] The input end of the first driving unit is electrically connected to the output end of the first logic gate circuit, and the output end is electrically connected to the enable end of the first indicator light.

[0020] According to an embodiment of the present utility model, in the above-mentioned control circuit, the control circuit further includes a third driving unit and a second indicator light;

[0021] The input end of the third driving unit is electrically connected to the output end of the second logic gate circuit, and the output end is electrically connected to the enable end of the second indicator light.

[0022] According to an embodiment of the present utility model, in the above control circuit, the control circuit further includes a third logic gate circuit, a fourth logic gate circuit, a fourth driving unit and a third indicator light;

[0023] The input end of the third logic gate circuit is electrically connected to the output end of the first comparison unit, the first input end of the fourth logic gate is electrically connected to the output end of the third logic gate circuit, the second input end is electrically connected to the output end of the second logic gate circuit, and the output end is electrically connected to the fourth driving unit, the output end of the fourth driving unit is electrically connected to the enable end of the third indicator light, the third logic gate circuit is configured to output a low level if the input signal is a high level and to output a high level if the input signal is a low level, and the fourth logic gate circuit is configured to output a high level if the input signals are all high levels and to output a low level if the input signals are low levels.

[0024] According to an embodiment of the present utility model, in the above-mentioned control circuit, the control circuit further includes a fifth logic gate circuit, a fifth driving unit and a fourth indicator light;

[0025] The input end of the fifth logic gate circuit is electrically connected to the output end of the third comparison unit, and the output end is electrically connected to the input end of the fifth driving unit, the output end of the fifth driving unit is electrically connected to the fourth indicator light, and the fifth logic gate circuit is configured to output a high level if any input signal is a high level, and to output a low level if all input signals are low levels;

[0026] According to an embodiment of the present utility model, in the above-mentioned control circuit, the first indicator light, the second indicator light, the third indicator light and the fourth indicator light have different luminous colors.

[0027] It should be understood that the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the present invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are included to provide a further understanding of the present invention, and they are included and constitute a part of this application. The accompanying drawings illustrate embodiments of the present invention and together with this specification serve to explain the principles of the present invention.

[0029] In the figure:

[0030] Figure 1 It is a structural diagram of a control circuit according to the utility model.

[0031] Explanation of the reference numerals: control circuit 100; first voltage detection unit 101; first comparison unit 102; shunt 103; second voltage detection unit 104; second comparison unit 105; first logic gate circuit 106; PWM signal generating unit 107; second logic gate circuit 108; temperature detection unit 109; third comparison unit 110; heat dissipation unit 111; fourth comparison unit 112; first drive unit 113; fan 114; second drive unit 115; first indicator light 116; third drive unit 117; second indicator light 118; third logic gate circuit 119; fourth logic gate circuit 120; fourth drive unit 121; third indicator light 122; fifth logic gate circuit 123; fifth drive unit 124; fourth indicator light 125; IGBT circuit 201; IGBT drive unit 202; brake resistor 203. DETAILED DESCRIPTION

[0032] Embodiments of the utility model will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the utility model, examples of which are shown in the accompanying drawings. Wherever possible, the same reference numerals will be used in all drawings to represent the same or similar parts. In addition, although the terms used in the utility model are selected from well-known and commonly used terms, some of the terms mentioned in the utility model specification may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description herein. In addition, it is required to understand the utility model not only by the actual terms used, but also by the meaning implied by each term.

[0033] The basic principles and preferred embodiments of the present invention are discussed in more detail with reference to the accompanying drawings. Figure 1 A novel control circuit 100 for a brake unit is shown. Figure 1 The control circuit 100 of the present invention mainly includes a first voltage detection unit 101 , a first comparison unit 102 , a shunt 103 , a second voltage detection unit 104 , a second comparison unit 105 , a first logic gate circuit 106 and a PWM signal generation unit 107 .

[0034] See also Figure 1 The first input terminal of the first comparison unit 102 is electrically connected to the output terminal of the first voltage detection unit 101 and the second input terminal is electrically connected to the first reference voltage. The first comparison unit 102 is configured to output a high level if the voltage of the first input terminal is greater than the first reference voltage. In practical applications, the two detection terminals of the first voltage detection unit 101 are respectively electrically connected to the positive and negative electrodes of the external DC bus voltage for connecting to the brake circuit.

[0035] See also Figure 1 In practical applications, the shunt 103 is electrically connected in series in an external brake circuit, and the shunt 103 is combined with the second voltage detection unit 104 to detect the load current of the brake circuit. Specifically, the two detection terminals of the second voltage detection unit 104 are electrically connected to the two output terminals of the shunt 103, respectively, the first input terminal of the second comparison unit 105 is electrically connected to the output terminal of the second voltage detection unit 104, and the second input terminal of the second comparison unit 105 is electrically connected to the second reference voltage. The second comparison unit 105 is configured to output a high level if the voltage of the first input terminal is greater than the second reference voltage.

[0036] See also Figure 1, a first input terminal of the first logic gate circuit 106 is electrically connected to the output terminal of the first comparison unit 102, and a second input terminal of the first logic gate circuit 106 is electrically connected to the output terminal of the second comparison unit 105. The first logic gate circuit 106 is configured to output a high level if both input signals are high level and to output a low level if any input signal is low level. The first logic gate circuit 106 is, for example but not limited to, an OR gate circuit.

[0037] See also Figure 1 , the enable terminal of the PWM signal generating unit 107 is electrically connected to the output terminal of the first logic gate circuit 106, and the PWM signal generating unit 107 is configured to generate a PWM signal if the enable terminal input is at a high level. In practical applications, the output terminal of the PWM signal generating unit 107 is electrically connected to the IGBT driving unit 202 in the external braking circuit to control the on and off of the IGBT to consume energy on the braking resistor 203 in the braking circuit; the PWM signal is preferably transmitted to the IGBT driving unit 202 via an optical fiber.

[0038] Optionally, the control circuit 100 may further include a second logic gate circuit 108. Figure 1 The first input terminal of the second logic gate circuit 108 is electrically connected to the output terminal of the second comparison unit 105, the second input terminal is electrically connected to the fault feedback terminal of the IGBT driving unit 202 in the external brake circuit, and the output terminal is electrically connected to the second input terminal of the first logic gate circuit 106. The second logic gate circuit 108 is configured to output a low level if any input signal is a high level and to output a high level if all input signals are low levels. The second logic gate circuit 108 is, for example but not limited to, a NOR gate circuit.

[0039] Optionally, the control circuit 100 may further include a heat dissipation unit 111, a temperature detection unit 109 and a third comparison unit 110. Figure 1 As shown, the temperature detection unit 109 is connected to the heat dissipation unit 111, the heat dissipation unit 111 is connected to the IGBT in the external brake circuit, the output end of the temperature detection unit 109 is electrically connected to the first input end of the third comparison unit 110, the second input end of the third comparison unit 110 is electrically connected to the third reference voltage and the output end is electrically connected to the third input end of the second logic gate circuit 108. In addition, when the applied brake unit includes the aforementioned heat dissipation unit 111, the temperature detection unit 109 is connected to the heat dissipation unit 111 connected to the IGBT in the brake circuit. The temperature detection unit 109 can be, for example, an NTC temperature detection unit 109, and an NTC thermistor can be embedded in the heat dissipation unit 111 to achieve connection, and the heat dissipation unit 111 and the IGBT are fixed to the heat sink, for example, by thermal conductive silicone grease.

[0040] Optionally, the control circuit 100 may further include a fourth comparing unit 112, a first driving unit 113 and a fan 114. Figure 1 As shown, the first input terminal of the fourth comparison unit 112 is electrically connected to the output terminal of the temperature detection unit 109 and the second input terminal is electrically connected to a fourth reference voltage, the fourth reference voltage is less than the third reference voltage, the first driving unit 113 is electrically connected between the output terminal of the fourth comparison unit 112 and the enable terminal of the fan 114, and the fourth comparison unit 112 is configured to output a high level if the voltage of the first input terminal is greater than the fourth reference voltage.

[0041] Optionally, the control circuit 100 further includes a second driving unit 115 and a first indicator light 116. Figure 1 As shown, the input end of the first driving unit 113 is electrically connected to the output end of the first logic gate circuit 106 and the output end is electrically connected to the enable end of the first indicator light 116 .

[0042] Optionally, the control circuit 100 further includes a third driving unit 117 and a second indicator light 118. Figure 1 As shown, the input end of the third driving unit 117 is electrically connected to the output end of the second logic gate circuit 108 and the output end is electrically connected to the enable end of the second indicator light 118 .

[0043] Optionally, the control circuit 100 further includes a third logic gate circuit 119, a fourth logic gate circuit 120, a fourth driving unit 121 and a third indicator light 122. Figure 1 As shown, the input end of the third logic gate circuit 119 is electrically connected to the output end of the first comparison unit 102, the first input end of the fourth logic gate is electrically connected to the output end of the third logic gate circuit 119, the second input end is electrically connected to the output end of the second logic gate circuit 108, and the output end is electrically connected to the fourth driving unit 121, and the output end of the fourth driving unit 121 is electrically connected to the enable end of the third indicator light 122. The third logic gate circuit 119 is configured to output a low level if the input signal is a high level and to output a high level if the input signal is a low level, and the fourth logic gate circuit 120 is configured to output a high level if the input signals are all high levels and to output a low level if the input signals are low levels; the third logic gate circuit 119 is, for example but not limited to, a NOT gate circuit, and the fourth logic gate circuit 120 is, for example but not limited to, an AND gate circuit.

[0044] Optionally, the control circuit 100 further includes a fifth logic gate circuit 123, a fifth driving unit 124 and a fourth indicator light 125. Figure 1As shown, the input end of the fifth logic gate circuit 123 is electrically connected to the output end of the third comparison unit 110, and the output end is electrically connected to the input end of the fifth driving unit 124, and the output end of the fifth driving unit 124 is electrically connected to the fourth indicator light 125. The fifth logic gate circuit 123 is configured to output a high level if any input signal is a high level and to output a low level if all input signals are low levels. The fifth logic gate circuit 123 is, for example but not limited to, an OR gate circuit.

[0045] In practical applications, the luminous colors of the first indicator light 116, the second indicator light 118, the third indicator light 122, and the fourth indicator light 125 can be designed to be different so as to better distinguish the indication information. The luminous colors of the first indicator light 116, the second indicator light 118, the third indicator light 122, and the fourth indicator light 125 can be designed to be the same, and the indication information can be distinguished by setting information labels under the corresponding indicator lights. In this way, on the one hand, indicator lights of various states are set for the control circuit 100 so that the user can obtain the state of the control circuit 100 in real time; on the other hand, different luminous colors are set for different indicator lights to better distinguish the indication information. In addition, the comparison unit described in the present application is preferably a voltage comparison unit.

[0046] In summary, the utility model proposes a control circuit 100 of a new structure, which detects the voltage on the DC bus. If it exceeds the upper limit of the preset value and there is no over-temperature fault, IGBT fault, or IGBT over-current, the PWM wave signal is sent to the IGBT drive unit through the optical fiber to control the on and off of the IGBT to achieve energy consumption braking; if the bus voltage is lower than the lower limit of the preset value, the PWM wave is blocked and the braking function is stopped. In addition, the temperature inside the device is determined by NTC temperature detection to control the start and stop of the cooling fan. The control circuit 100 does not rely on a control scheme combining a chip controller and software, but only achieves the control effect of the braking unit through a pure logic circuit, which reduces the design cost, software maintenance cost, and material cost, and meets the low-cost user needs. In addition, when controlling the braking unit, the bus voltage detection is combined with one or more of "judgment result and load current detection and judgment result, temperature detection and judgment result, and IGBT fault detection and judgment result" to achieve effective control of the braking circuit, and the control result has high reliability. In addition, indicator lights of various states are set for the control circuit 100, so that the user can obtain the state of the control circuit 100 in real time.

[0047] It should be noted that in the claims and description of this patent, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0048] While the present invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

[0049] The present invention is shown and described in detail above through the accompanying drawings and preferred embodiments. However, the present invention is not limited to these disclosed embodiments. Based on the above multiple embodiments, those skilled in the art can know that different means in the above different embodiments can be combined to obtain more embodiments of the present invention, and these embodiments are also within the protection scope of the present invention.

Claims

1. A control circuit, applied to a brake unit, characterized in that: The control circuit (100) comprises: A first voltage detection unit (101) and a first comparison unit (102), wherein a first input terminal of the first comparison unit (102) is electrically connected to an output terminal of the first voltage detection unit (101) and a second input terminal is electrically connected to a first reference voltage, and the first comparison unit (102) is configured to output a high level if a voltage at the first input terminal is greater than the first reference voltage; A current divider (103), a second voltage detection unit (104) and a second comparison unit (105), wherein two detection terminals of the second voltage detection unit (104) are respectively electrically connected to two output terminals of the current divider (103), a first input terminal of the second comparison unit (105) is electrically connected to the output terminal of the second voltage detection unit (104) and a second input terminal is electrically connected to a second reference voltage, and the second comparison unit (105) is configured to output a high level if the voltage at the first input terminal is greater than the second reference voltage; a first logic gate circuit (106), wherein a first input terminal of the first logic gate circuit (106) is electrically connected to an output terminal of the first comparison unit (102) and a second input terminal of the first logic gate circuit (106) is electrically connected to an output terminal of the second comparison unit (105), and the first logic gate circuit (106) is configured to output a high level if both input signals are at a high level and to output a low level if any input signal is at a low level; A PWM signal generating unit (107), wherein an enable terminal of the PWM signal generating unit (107) is electrically connected to the output terminal of the first logic gate circuit (106), and the PWM signal generating unit (107) is configured to generate a PWM signal if the enable terminal input is at a high level.

2. The control circuit according to claim 1, characterized in that: The two detection ends of the first voltage detection unit (101) are respectively electrically connected to the positive and negative poles of the external DC bus voltage connected to the braking circuit, the shunt (103) is electrically connected in series in the external braking circuit, and the output end of the PWM signal generating unit (107) is electrically connected to the IGBT driving unit (202) in the external braking circuit.

3. The control circuit according to claim 2, characterized in that: The control circuit (100) further includes a second logic gate circuit (108); The first input terminal of the second logic gate circuit (108) is electrically connected to the output terminal of the second comparison unit (105), the second input terminal is electrically connected to the fault feedback terminal of the IGBT drive unit (202) in the external braking circuit, and the output terminal is electrically connected to the second input terminal of the first logic gate circuit (106). The second logic gate circuit (108) is configured to output a low level if any input signal is a high level, and to output a high level if all input signals are low levels.

4. The control circuit according to claim 3, characterized in that: The control circuit (100) further comprises a temperature detection unit (109) and a third comparison unit (110); The temperature detection unit (109) is connected to a heat dissipation unit (111) connected to the IGBT in an external brake circuit, an output end of the temperature detection unit (109) is electrically connected to a first input end of the third comparison unit (110), a second input end of the third comparison unit (110) is electrically connected to a third reference voltage and an output end is electrically connected to a third input end of the second logic gate circuit (108), and a high level is output when a voltage at the first input end of the third comparison unit (110) is greater than the third reference voltage.

5. The control circuit according to claim 3, characterized in that: The control circuit (100) further comprises a temperature detection unit (109), a third comparison unit (110) and a heat dissipation unit (111); The temperature detection unit (109) is connected to the heat dissipation unit (111), the heat dissipation unit (111) is connected to an IGBT in an external brake circuit, an output end of the temperature detection unit (109) is electrically connected to a first input end of the third comparison unit (110), a second input end of the third comparison unit (110) is electrically connected to a third reference voltage, and an output end is electrically connected to a third input end of the second logic gate circuit (108).

6. The control circuit according to claim 4 or 5, characterized in that: The control circuit (100) further comprises a fourth comparison unit (112), a first drive unit (113) and a fan (114); The first input terminal of the fourth comparison unit (112) is electrically connected to the output terminal of the temperature detection unit (109) and the second input terminal is electrically connected to a fourth reference voltage, the fourth reference voltage is less than the third reference voltage, the first drive unit (113) is electrically connected between the output terminal of the fourth comparison unit (112) and the enable terminal of the fan (114), and the fourth comparison unit (112) is configured to output a high level if the voltage of the first input terminal is greater than the fourth reference voltage.

7. The control circuit according to claim 6, characterized in that: The control circuit (100) further comprises a second driving unit (115) and a first indicator light (116); The input end of the first driving unit (113) is electrically connected to the output end of the first logic gate circuit (106), and the output end is electrically connected to the enable end of the first indicator light (116).

8. The control circuit according to claim 7, characterized in that: The control circuit (100) further includes a third driving unit (117) and a second indicator light (118); The input end of the third driving unit (117) is electrically connected to the output end of the second logic gate circuit (108), and the output end is electrically connected to the enable end of the second indicator light (118).

9. The control circuit according to claim 8, characterized in that: The control circuit (100) further comprises a third logic gate circuit (119), a fourth logic gate circuit (120), a fourth driving unit (121) and a third indicator light (122); The input end of the third logic gate circuit (119) is electrically connected to the output end of the first comparison unit (102); the first input end of the fourth logic gate is electrically connected to the output end of the third logic gate circuit (119), the second input end is electrically connected to the output end of the second logic gate circuit (108), and the output end is electrically connected to the fourth driving unit (121); the output end of the fourth driving unit (121) is electrically connected to the enable end of the third indicator light (122); the third logic gate circuit (119) is configured to output a low level if the input signal is a high level, and to output a high level if the input signal is a low level; the fourth logic gate circuit (120) is configured to output a high level if the input signals are all high levels, and to output a low level if the input signals are low levels.

10. The control circuit according to claim 9, characterized in that: The control circuit (100) further comprises a fifth logic gate circuit (123), a fifth driving unit (124) and a fourth indicator light (125); The input end of the fifth logic gate circuit (123) is electrically connected to the output end of the third comparison unit (110), and the output end is electrically connected to the input end of the fifth driving unit (124); the output end of the fifth driving unit (124) is electrically connected to the fourth indicator light (125); the fifth logic gate circuit (123) is configured to output a high level if any input signal is at a high level, and to output a low level if all input signals are at a low level; The first indicator light (116), the second indicator light (118), the third indicator light (122) and the fourth indicator light (125) have different luminous colors.

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