Collector driving signal power-on delay protection circuit

Abstract

The invention discloses a collector driving signal power-on delay protection circuit, which is connected between a control signal input end of an ignition driving chip and a power supply, and comprises a delay module used for setting delay time and delaying output of a control signal according to preset delay time; the switch control module is used for controlling opening or closing of a control signal output to the ignition driving chip; the invention further discloses a delay protection method which is applied to the collector driving signal power-on delay protection circuit and comprises the following steps: S1, at the power-on moment of the ignition module, the delay module delays a control signal output to the ignition driving chip according to a preset delay time, and the ignition module outputs the control signal to the ignition driving chip; at the moment, the switch control module controls to close a control signal output to the ignition driving chip; s2, during the time delay action period of the time delay module, waiting for the ignition driving chip to reach a stable state; and S3, after the ignition driving chip operates stably, the delay module stops working, and the switch control module controls to start the control signal output to the ignition driving chip. The control signal input to the ignition driving chip is subjected to delay processing, so that the ignition module is prevented from enabling the power tube to be in a long-time conduction state at the moment of electrifying, transient heat generation of the power tube is reduced, the reliability of the ignition module is improved, the service life of the ignition module is prolonged, the failure rate of an ignition coil is reduced, and the service life of the ignition coil is prolonged. Effective and stable ignition of the ignition coil is ensured, so that the dynamic stability of an automobile is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of automobile engine electronic ignition control, and in particular to a collector drive signal power-on delay protection circuit. Background Art

[0002] In the field of electronic ignition control of automobile engines, ECU refers to the electronic control unit of the engine, and the ECU control signal refers to the EST control signal output by the ECU. The ignition module of the automobile engine control system controls the ignition coil to ignite according to the ECU control signal. The ignition module includes an ignition driver chip and a power tube. Specifically, the ignition driver chip receives the ECU control signal, controls the conduction and cutoff of the power tube, and then controls the current of the primary winding of the ignition coil, which ultimately affects the high voltage generated by the secondary winding of the ignition coil to achieve ignition control.

[0003] Since the control signal of the ignition module outputted by the open collector changes with the power supply, but the control signal input terminal of the ignition driver chip of the existing open collector output ignition module does not perform delay processing, under ideal conditions, the control signal follows the power supply output to the ignition driver chip, which can control the normal operation of the power tube. However, in actual applications, due to the fast power-on instant of the ignition module, the control signal input to the ignition driver chip is in a long-term high-level state. When the ignition driver chip fails to initialize and run stably, the permanent long-term (permanent high-level) protection function is not turned on, and the turn-on signal will be output to keep the power tube in a long-term conduction state. The transient heat generation of the power tube increases, which can easily cause damage to the power tube and make the ignition module function ineffective. Summary of the invention

[0004] The purpose of the present invention is to provide a collector drive signal power-on delay protection circuit, which delays the control signal input to the ignition drive chip to avoid the ignition module from putting the power tube in a long-term conduction state at the moment of power-on, reduce the transient heat generation of the power tube, improve the reliability of the ignition module, extend the service life of the ignition module, reduce the failure rate of the ignition coil, ensure the ignition coil to ignite effectively and stably, thereby ensuring the power stability of the vehicle.

[0005] In order to achieve the above purpose, the following technical solutions are adopted:

[0006] A collector drive signal power-on delay protection circuit, the delay protection circuit is connected between the control signal input terminal of an ignition drive chip and a power supply, comprising: a delay module, used to set a delay time, and delay the output of a control signal according to a preset delay time; a switch control module, used to control the opening or closing of the control signal output to the ignition drive chip; and also comprising a delay protection method, which is applied to the above-mentioned collector drive signal power-on delay protection circuit, comprising the following steps: S1: at the moment when the ignition module is powered on, the delay module delays the control signal output to the ignition drive chip according to a preset delay time, and at this time the switch control module controls the closing of the control signal output to the ignition drive chip; S2: during the delay action of the delay module, wait for the ignition drive chip to reach a stable state; S3: after the ignition drive chip runs stably, the delay module stops working, and the switch control module controls the opening of the control signal output to the ignition drive chip.

[0007] Preferably, the delay module includes a second capacitor, a second resistor, and a first diode; the first end of the second capacitor is connected to the power supply; the second end of the second capacitor, the first end of the second resistor, and the cathode of the first diode are connected in common; the second end of the second resistor and the anode of the first diode are grounded.

[0008] Preferably, the switch control module includes a first switch tube and a third resistor; the first end of the third resistor is connected to the first end of the second resistor; the second end of the third resistor is connected to the controlled end of the first switch tube; the input end of the first switch tube is connected to the control signal input end of the ignition drive chip, and the output end of the first switch tube is grounded.

[0009] Preferably, the time-delay protection circuit further comprises a surge protection module connected to the control signal input terminal of the ignition driver chip, for preventing surge voltage from damaging the ignition driver chip.

[0010] Preferably, the surge protection module includes a second voltage regulator tube and a fourth resistor; the cathode of the second voltage regulator tube and the first end of the fourth resistor are connected to the control signal input end of the ignition drive chip; the second end of the fourth resistor is connected to the ECU output signal end; the anode of the second voltage regulator tube is grounded.

[0011] Preferably, the first switch tube is implemented by a triode; the collector, emitter and base of the triode correspond to the input end, output end and controlled end of the first switch tube respectively.

[0012] By adopting the above scheme, the beneficial effects of the present invention are:

[0013] The present invention provides a collector drive signal power-on delay protection circuit, which delays the control signal input to the ignition drive chip to avoid the ignition module from putting the power tube in a long-term conduction state at the moment of power-on, reduces the transient heat generation of the power tube, improves the reliability of the ignition module, extends the service life of the ignition module, reduces the failure rate of the ignition coil, ensures the effective and stable ignition of the ignition coil, and thus ensures the power stability of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a principle block diagram of the present invention;

[0015] Figure 2 is a detailed circuit diagram of the present invention;

[0016] The accompanying drawings illustrate:

[0017] 1—Delay module, 2—Switch control module,

[0018] 3—surge protection module, 4—ignition driver chip,

[0019] 5—Power tube. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0021] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0022] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0023] Reference Figures 1 to 2 As shown, the present invention provides a collector drive signal power-on delay protection circuit, which is connected between the control signal input terminal of the ignition drive chip 4 and the power supply, and includes: a delay module ·, which is used to set the delay time and delay the output of the control signal according to the preset delay time; a switch control module 2, which is used to control the opening or closing of the control signal output to the ignition drive chip 4; and also includes a delay protection method, which is applied to the above-mentioned collector drive signal power-on delay protection circuit, and includes the following steps: S1: at the moment when the ignition module is powered on, the delay module 1 delays the control signal output to the ignition drive chip 4 according to the preset delay time, and at this time the switch control module 2 controls the closing of the control signal output to the ignition drive chip 4; S2: during the delay action of the delay module 1, wait for the ignition drive chip 4 to reach a stable state; S3: after the ignition drive chip 4 runs stably, the delay module stops working, and the switch control module 2 controls the opening of the control signal output to the ignition drive chip 4.

[0024] The collector drive signal power-on delay protection circuit provided by the present invention is mainly for the ignition module with open collector output. By adding a delay protection circuit at the control signal input end of the ignition drive chip 4, the control signal output to the ignition drive chip 4 is delayed at the moment of power-on of the ignition module, so as to prevent the power tube from being in the on state for a long time due to the rapid change of the control signal at the moment of power-on. After the ignition drive chip 4 completes initialization and runs stably, the control signal is received again, so as to avoid the power tube 5 being in the long on state caused by the moment of power-on of the ignition module, reduce the transient heat generation of the power tube 5, improve the reliability of the ignition module, extend the service life of the ignition module, reduce the failure rate of the ignition coil, ensure the effective and stable ignition of the ignition coil, and thus ensure the power stability of the vehicle.

[0025] Delay module 1:

[0026] Please continue to refer to Figure 2The delay module 1 includes a second capacitor C2, a second resistor R2, and a first diode D1; the first end of the second capacitor C2 is connected to the power supply; the second end of the second capacitor C2, the first end of the second resistor R2, and the cathode of the first diode D1 are connected in common; the second end of the second resistor R2 and the anode of the first diode D1 are grounded. The second capacitor C2, the second resistor R2, and the first diode D1 constitute a charge-discharge loop, forming the main delay part. The delay time is preset and debugged according to the characteristics of the ignition driver chip 4 and the actual use. The length of the delay time is determined by the second capacitor C2, that is, it is set according to the capacitance of the second capacitor C2, and the delay is achieved by charging and discharging the second capacitor C2; the first diode D1 is a switching diode, which is used in the discharge loop of the second capacitor C2 and plays a role of rapid discharge.

[0027] Switch control module 2:

[0028] Please continue to refer to Figure 2 The switch control module 2 includes a first switch tube Q1 and a third resistor R3, which act as a switch and are used to control the opening or closing of a control signal output to the ignition drive chip 4; the first end of the third resistor R3 is connected to the first end of the second resistor R2; the second end of the third resistor R3 is connected to the controlled end of the first switch tube Q1; the input end of the first switch tube Q1 is connected to the control signal input end of the ignition drive chip 4, and the output end of the first switch tube Q1 is grounded.

[0029] Surge protection module 3:

[0030] Please continue to refer to Figure 2 , the delay protection circuit also includes a surge protection module 3 connected to the control signal input end of the ignition driver chip 4, which is used to prevent surge voltage from damaging the ignition driver chip 4. The surge protection module 3 includes a second voltage regulator tube D2 and a fourth resistor R4; the cathode of the second voltage regulator tube D2 and the first end of the fourth resistor R4 are connected to the control signal input end of the ignition driver chip 4; the second end of the fourth resistor R4 is connected to the ECU output signal end; the anode of the second voltage regulator tube D2 is grounded. The surge protection module 3 is used to protect the control signal input port of the ignition driver chip 4 to prevent surge voltage from damaging the ignition driver chip 4.

[0031] In a specific embodiment, the first switch tube is implemented by a triode; the collector, emitter and base of the triode correspond to the input end, output end and controlled end of the first switch tube respectively.

[0032] Please continue to refer to Figure 2The ignition driver chip 4 adopts a car-grade driver chip, with a simplified peripheral circuit, fewer components, and high reliability. After the ECU collector is open-circuited, the state of the ECU output signal changes with the power supply through the pull-up resistor R1. The pull-up resistor R1 acts as an anti-surge to prevent the surge voltage at the power supply end from being connected to the ECU output signal end. The first capacitor C1 is a filter capacitor that acts as a signal filter.

[0033] Since the control signal of the ignition module output by the open collector changes with the power supply, while the conventional ignition module does not follow the power supply. Therefore, the collector drive signal power-on delay protection circuit provided by the present invention is mainly for the ignition module with open collector output. The high-level state of the ECU control signal follows the power supply voltage, and is then output to the control signal input end of the ignition drive chip 4. The ignition drive chip 4 outputs a drive signal to control the opening and closing of the power tube 5. When the ignition drive chip 4 is not running stably, it is equivalent to the ignition drive chip 4 judging that the input control signal has always been at a high level, and then the ignition drive chip 4 will always output a signal that turns on the power tube 5 and will not turn it off.

[0034] In addition, a delay protection method is also provided, which is applied to the above-mentioned collector drive signal power-on delay protection circuit, and includes the following steps:

[0035] 1) Power on: When the power module starts supplying power, the ignition module will receive the power signal;

[0036] 2) Delay protection takes effect: At the moment the power is turned on, the delay protection circuit starts to work, and the delay module 1 delays the control signal output to the ignition driver chip 4 according to the preset delay time. At this time, the switch control module 2 controls to turn off the control signal output to the ignition driver chip 4;

[0037] 3) The ignition driver chip 4 is stable: During the delay period, the ignition driver chip 4 is waiting to complete the self-check and initialization process, reach a stable state, and be ready to receive control signals;

[0038] 4) The ignition module works normally: Once the ignition driver chip 4 runs stably, the delay module 1 stops working, and the switch control module 2 controls the control signal output to the ignition driver chip 4. The control signal is then input into the ignition driver chip 4. The ignition driver chip 4 controls the on and off of the power tube 5 according to the received signal, thereby controlling the normal operation of the ignition coil.

[0039] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention. Obviously, the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A collector drive signal power-on delay protection circuit, characterized in that: The time delay protection circuit is connected between the control signal input terminal of the ignition drive chip and the power supply, and includes: The delay module is used to set the delay time and delay the output of the control signal according to the preset delay time; A switch control module, used to control the on or off of the control signal output to the ignition driver chip; Also included is a time-delay protection method, which is applied to the above collector drive signal power-on delay protection circuit, and includes the following steps: S1: When the ignition module is powered on, the delay module delays the control signal output to the ignition driver chip according to the preset delay time. At this time, the switch control module controls to turn off the control signal output to the ignition driver chip; S2: During the delay period of the delay module, wait for the ignition driver chip to reach a stable state; S3: After the ignition driver chip runs stably, the delay module stops working, and the switch control module controls to turn on the control signal output to the ignition driver chip.

2. The collector drive signal power-on delay protection circuit according to claim 1, characterized in that: The delay module includes a second capacitor, a second resistor, and a first diode; the first end of the second capacitor is connected to a power supply; the second end of the second capacitor, the first end of the second resistor, and the cathode of the first diode are connected in common; the second end of the second resistor and the anode of the first diode are grounded.

3. The collector drive signal power-on delay protection circuit according to claim 2, characterized in that: The switch control module includes a first switch tube and a third resistor; the first end of the third resistor is connected to the first end of the second resistor; the second end of the third resistor is connected to the controlled end of the first switch tube; the input end of the first switch tube is connected to the control signal input end of the ignition drive chip, and the output end of the first switch tube is grounded.

4. The collector drive signal power-on delay protection circuit according to claim 3, characterized in that: The time delay protection circuit also includes a surge protection module connected to the control signal input terminal of the ignition drive chip, which is used to prevent surge voltage from damaging the ignition drive chip.

5. The collector drive signal power-on delay protection circuit according to claim 4, characterized in that: The surge protection module includes a second voltage regulator tube and a fourth resistor; the cathode of the second voltage regulator tube and the first end of the fourth resistor are connected to the control signal input end of the ignition drive chip; the second end of the fourth resistor is connected to the ECU output signal end; The anode of the second voltage regulator tube is grounded.

6. The collector drive signal power-on delay protection circuit according to claim 3, characterized in that: The first switch tube is implemented by a triode; the collector, emitter and base of the triode correspond to the input end, output end and controlled end of the first switch tube respectively.

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