A collector drive signal power-on delay protection circuit

Abstract

The application 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, which is used for setting a delay time and delaying output of a control signal according to the preset delay time; and a switch control module, which is used for controlling opening or closing of the control signal output to the ignition driving chip; and a delay protection method applied to the collector driving signal power-on delay protection circuit, which comprises the following steps: S1, at a power-on moment of an ignition module, the delay module delays the control signal output to the ignition driving chip according to a preset delay time, and the switch control module controls closing of the control signal output to the ignition driving chip; S2, during the delay action of the delay module, waiting for the ignition driving chip to reach a stable state; and S3, after the ignition driving chip is stably operated, the delay module stops working, and the switch control module controls opening of the control signal output to the ignition driving chip. The application delays the control signal input to the ignition driving chip, avoids that the ignition module makes a power tube in a long-time conduction state at a power-on moment, reduces transient heat generation of the power tube, improves the reliability of the ignition module, prolongs the service life of the ignition module, reduces the failure rate of an ignition coil, ensures effective and stable ignition of the ignition coil, and thus guarantees the automobile power stability.

Description

Technical Field

[0001] This invention relates to the field of electronic ignition control technology for automotive engines, and in particular to a collector drive signal power-on delay protection circuit. Background Technology

[0002] In the field of automotive engine electronic ignition control, ECU refers to the engine electronic control unit, and ECU control signal refers to the EST control signal output by the ECU. The ignition module of the automotive 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 transistor. Specifically, the ignition driver chip receives the ECU control signal, controls the conduction and cutoff of the power transistor, and then controls the current in the primary winding of the ignition coil, ultimately affecting the high voltage generated in the secondary winding of the ignition coil to achieve ignition control.

[0003] Because the ignition module control signal output by the open collector changes with the power supply, existing open-collector ignition modules lack delay processing at the control signal input terminal of the ignition driver chip. Ideally, the control signal output to the ignition driver chip following the power supply should control the power transistor to operate normally. However, in practical applications, due to the rapid power-on of the ignition module, the control signal input to the ignition driver chip is at a high level for an extended period. If the ignition driver chip fails to initialize and stabilize, the permanent high-level protection function will not be activated, resulting in an output enable signal that keeps the power transistor in a prolonged conducting state. This increases the transient heat generation of the power transistor, easily leading to its damage and causing the ignition module to malfunction. Summary of the Invention

[0004] The purpose of this invention is to provide a collector drive signal power-on delay protection circuit. By delaying the control signal input to the ignition drive chip, the circuit avoids the power transistor from being in a prolonged conducting state at the moment of power-on, thereby reducing the transient heat generation of the power transistor, improving the reliability of the ignition module, extending the service life of the ignition module, reducing the failure rate of the ignition coil, and ensuring effective and stable ignition of the ignition coil, thus guaranteeing the stability of the vehicle's power.

[0005] To achieve the above objectives, the following technical solution is adopted:

[0006] A collector drive signal power-on delay protection circuit, the delay protection circuit being connected between the control signal input terminal of an ignition driver chip and a power supply, includes: a delay module for setting a delay time and delaying the output of the control signal according to a preset delay time; a switch control module for controlling the opening or closing of the control signal output to the ignition driver chip; and a delay protection method applied to the above-mentioned collector drive signal power-on delay protection circuit, including the following steps: S1: At the instant the ignition module is powered on, the delay module delays the output of the control signal to the ignition driver chip according to a preset delay time, at which time the switch control module controls the closing of the control signal output to the ignition driver chip; S2: During the delay period of the delay module, the ignition driver chip is waited for to reach a stable state; S3: After the ignition driver chip is running stably, the delay module stops working, and the switch control module controls the opening of the control signal output to the ignition driver 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 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 all connected together; 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 transistor 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 transistor; the input end of the first switch transistor is connected to the control signal input end of the ignition driver chip, and the output end of the first switch transistor is grounded.

[0009] Preferably, the delay protection circuit further includes a surge protection module connected to the control signal input terminal of the ignition driver chip to prevent surge voltage from damaging the ignition driver chip.

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

[0011] Preferably, the first switching transistor is implemented using a bipolar transistor; the collector, emitter, and base of the bipolar transistor correspond to the input, output, and controlled terminals of the first switching transistor, respectively.

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

[0013] This invention provides a collector drive signal power-on delay protection circuit. By delaying the control signal input to the ignition drive chip, it prevents the power transistor from being in a prolonged conducting state at the moment of power-on, reduces transient heat generation of the power transistor, improves the reliability of the ignition module, extends the service life of the ignition module, reduces the failure rate of the ignition coil, and ensures effective and stable ignition of the ignition coil, thereby ensuring the stability of the vehicle's power. Attached Figure Description

[0014] Figure 1 This is a schematic diagram illustrating the principle of the present invention.

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

[0016] The following are explanations of the labels in the attached diagram:

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

[0018] 3—Surge protection module, 4—Ignition driver chip,

[0019] 5—Power transistor. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0021] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

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

[0024] This invention provides a collector drive signal power-on delay protection circuit, primarily targeting ignition modules with open-collector outputs. By adding a delay protection circuit to the control signal input terminal of the ignition driver chip 4, the control signal output to the ignition driver chip 4 is delayed at the moment of power-on of the ignition module. This prevents the power transistor from remaining in a conducting state for an extended period due to rapid changes in the control signal at the moment of power-on. The control signal is only received after the ignition driver chip 4 has completed initialization and is operating stably. This avoids the power transistor 5 remaining in a prolonged conducting state due to the moment of power-on of the ignition module, reduces transient heat generation in the power transistor 5, improves the reliability of the ignition module, extends its service life, reduces the failure rate of the ignition coil, and ensures effective and stable ignition, thereby guaranteeing the stability of the vehicle's power.

[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 terminal of the second capacitor C2 is connected to the power supply. The second terminal of the second capacitor C2, the first terminal of the second resistor R2, and the cathode of the first diode D1 are all connected together. The second terminal 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 form a charging and discharging circuit, constituting the main delay section. The delay time is preset and adjusted according to the characteristics of the ignition driver chip 4 and actual usage. The delay time is determined by the second capacitor C2, i.e., set according to the capacitance value of the second capacitor C2. The delay is achieved through the charging and discharging of the second capacitor C2. The first diode D1 is a switching diode used in the discharge circuit of the second capacitor C2, serving a rapid discharge function.

[0027] Switch control module 2:

[0028] Please continue to refer to Figure 2 The switch control module 2 includes a first switch transistor Q1 and a third resistor R3, which function as a switch to control the control signal output to the ignition driver chip 4 to be turned on or off. 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 transistor Q1. The input end of the first switch transistor Q1 is connected to the control signal input end of the ignition driver chip 4, and the output end of the first switch transistor 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 terminal of the ignition driver chip 4, used to prevent surge voltage from damaging the ignition driver chip 4. The surge protection module 3 includes a second Zener diode D2 and a fourth resistor R4; the cathode of the second Zener diode D2 and the first end of the fourth resistor R4 are both connected to the control signal input terminal of the ignition driver chip 4; the second end of the fourth resistor R4 is connected to the ECU output signal terminal; the anode of the second Zener diode D2 is grounded. The surge protection module 3 is used to protect the control signal input port of the ignition driver chip 4, preventing surge voltage from damaging the ignition driver chip 4.

[0031] In one specific embodiment, the first switching transistor is implemented using a bipolar transistor; the collector, emitter, and base of the bipolar transistor correspond to the input terminal, output terminal, and controlled terminal of the first switching transistor, respectively.

[0032] Please continue to refer to Figure 2The ignition driver chip 4 uses an automotive-grade driver chip, with simplified peripheral circuitry, fewer components, and high reliability. After the ECU's collector is open, the state of the ECU's output signal changes with the power supply, controlled by the pull-up resistor R1. The pull-up resistor R1 acts as an anti-surge resistor, preventing surge voltage from the power supply terminal from entering the ECU's output signal terminal. The first capacitor C1 is a filter capacitor, serving as a signal filter.

[0033] Because the ignition module control signal output by the open collector changes with the power supply, while that of a conventional ignition module does not, the power-on delay protection circuit for the collector drive signal provided in this invention is mainly for ignition modules with open collector output. The ECU control signal, in a high-level state, follows the power supply voltage and is then output to the control signal input terminal of the ignition driver chip 4. The ignition driver chip 4 outputs a drive signal to control the on and off of the power transistor 5. When the ignition driver chip 4 is not running stably, it is equivalent to the ignition driver chip 4 judging that the input control signal is always high, and therefore the ignition driver chip 4 will continuously output a signal that keeps the power transistor 5 on and prevents it from turning off.

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

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

[0036] 2) Delay protection in action: At the moment the power is turned on, the delay protection circuit starts to work. The delay module 1 delays the output of the control signal to the ignition driver chip 4 according to the preset delay time. At this time, the switch control module 2 controls the shutdown of the control signal output to the ignition driver chip 4.

[0037] 3) Ignition driver chip 4 stabilizes: During the delay period, wait for the ignition driver chip 4 to complete the self-test and initialization process, reach a stable state, and be ready to receive control signals;

[0038] 4) Normal operation of the ignition module: Once the ignition driver chip 4 is running stably, the delay module 1 stops working, and the switch control module 2 controls the output of the control signal to the ignition driver chip 4. The control signal is then input into the ignition driver chip 4, and the ignition driver chip 4 controls the conduction and cutoff of the power transistor 5 according to the received signal, thereby controlling the normal operation of the ignition coil.

[0039] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention. Obviously, the above embodiments of the present invention are merely examples to clearly illustrate the present invention and are not intended to limit the implementation of the present invention. For those skilled in the art, various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A collector drive signal power-on delay protection circuit, characterized in that, The delay protection circuit is connected between the control signal input terminal of the ignition driver 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; The switch control module is used to control the control signals output to the ignition driver chip to turn on or off. It also includes a delay protection method applied to the above-mentioned collector drive signal power-on delay protection circuit, comprising the following steps: S1: At the moment the ignition module is powered on, the delay module outputs the control signal to the ignition driver chip after a preset delay time. At this time, the switch control module controls the shutdown of 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 has been running stably, the delay module stops working, and the switch control module controls the output of the control signal to the ignition driver chip. The delay module includes a second capacitor, a second resistor, and a first diode; the first terminal of the second capacitor is connected to a power supply; the second terminal of the second capacitor, the first terminal of the second resistor, and the cathode of the first diode are all connected together; the second terminal of the second resistor and the anode of the first diode are grounded. The switch control module includes a first switch transistor and a third resistor; the first end of the third resistor is connected to the first end of a second resistor; the second end of the third resistor is connected to the controlled end of the first switch transistor; the input end of the first switch transistor is connected to the control signal input end of the ignition driver chip, and the output end of the first switch transistor is grounded. The first switching transistor is implemented using a bipolar transistor; the collector, emitter, and base of the bipolar transistor correspond to the input, output, and controlled terminals of the first switching transistor, respectively.

2. The collector drive signal power-on delay protection circuit according to claim 1, characterized in that, The delay protection circuit also includes a surge protection module connected to the control signal input terminal of the ignition driver chip to prevent surge voltage from damaging the ignition driver chip.

3. The collector drive signal power-on delay protection circuit according to claim 2, characterized in that, The surge protection module includes a second Zener diode and a fourth resistor; the cathode of the second Zener diode and the first end of the fourth resistor are connected to the control signal input terminal of the ignition drive chip; the second end of the fourth resistor is connected to the output signal terminal of the ECU; and the anode of the second Zener diode is grounded.

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