CN201206526Y

CN201206526Y - Ignition coil driving circuit

Info

Publication number: CN201206526Y
Application number: CNU2008201159176U
Authority: CN
Inventors: 沈强; 王世友; 汪武东
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2008-05-30
Filing date: 2008-05-30
Publication date: 2009-03-11
Anticipated expiration: 2018-05-30

Abstract

The utility model provides a driving circuit for an ignition coil. The driving circuit for the ignition coil comprises an insulated gate bipolar transistor (P1) and a protective circuit, wherein, the protective circuit comprises a triode (T1) and a voltage-regulating resistor (VR1), the voltage-regulating resistor (VR1) is connected in parallel between the base electrode and the emitting electrode of the triode (T1), the emitting electrode of the triode (T1) is grounded, and the collecting electrode and the base electrode of the triode (T1) are respectively connected with the grid electrode and the source electrode of the insulated gate bipolar transistor (P1). By adopting the protective circuit, the current flowing in the insulated gate bipolar transistor IGBT can be limited, and the secondary ignition coil can be prevented from being burnt out due to excessively high current in the primary ignition coil.

Description

A kind of spark coil drive circuit

Technical field

The utility model relates to a kind of spark coil drive circuit.

Background technique

Motor is the core drive position of whole automobile, and the inefficacy of spark coil will directly cause car load to cast anchor in the electronic ignition type explosive motor.Therefore, in order to improve the performance of car load, the safety prevention measure that improves spark coil has become the problem that presses for solution.In the electronic ignition type explosive motor, the firing mode employing charges and discharge magnetic fast to high inductance coil and produces high instantaneous voltage, and the transformer action by Secondary coil produces higher voltage again, thereby comes fire fuel by spark plug discharge generation spark.If the control ON time of EEM system is long, it is saturated to cause spark coil to magnetize, and makes the instantaneous increase of electric current, thereby burns secondary spark coil.

Fig. 1 is existing spark coil drive circuit, this circuit comprises primary ignition coil 1, secondary spark coil 2, spark plug 3, insulated gate bipolar transistor (IGBT) P1 and resistance R 11, annexation as shown in Figure 1, the end that resistance R 11 does not link to each other with the grid of IGBT P1 is as fire signal input end 5, the source electrode of IGBTP1 is as igniting ground 6 and ground connection, and the end that primary ignition coil 1 does not link to each other with the drain electrode of IGBT P1 is as priming supply end 7.When the fire signal of fire signal input end 5 inputs is high level, described IGBT P1 conducting, connected primary ignition coil 1 produces transient current.Because described primary ignition coil 1 has the effect that suppresses electric current,, reach maximum value up to the coil saturated after-current that magnetizes so electric current can slowly increase.Saturated when reaching certain hour when magnetizing, described fire signal becomes low level from high level, and IGBT P1 is ended, thereby the electric current of primary ignition coil 1 is produced very big induced voltage by insantaneous break in primary ignition coil 1.Because the number of turn of secondary spark coil 2 will be much larger than the number of turn of primary ignition coil 1, so the induced voltage that produces on secondary spark coil 2 is also much larger than the induced voltage that produces on primary ignition coil 1, therefore obtain high induction voltage, this high pressure produces spark by the discharge of described spark plug 3, thereby finishes igniting.

Existing spark coil drive circuit is by insulated gate bipolar transistor (IGBT) control, yet that uses at present often is plain edition IGBT, does not possess current-limiting function, and electric current increases the back spark coil and is in the state of magnetizing for a long time, easily the spot failure fire coil.Also have at present the IGBT of part intelligence, it is compared with medium-sized IGBT, has to avoid the long and function that causes spark coil to damage of fire signal load time, but because the price of described intelligent IGBT is too expensive, its application is restricted.

The model utility content

The purpose of this utility model is to make spark coil be in the state of magnetizing for a long time and the shortcoming that causes spark coil to damage easily at existing spark coil drive circuit, and a kind of spark coil drive circuit of causing spark coil to damage of being difficult for is provided.

The spark coil drive circuit that the utility model provides comprises insulated gate bipolar transistor (IGBT); wherein; this spark coil drive circuit also comprises protective circuit; described protective circuit comprises first triode and regulating resistor; described regulating resistor is connected in parallel between the base stage and emitter of described first triode; and the grounded-emitter connection of this first triode, the collector electrode of this first triode links to each other with source electrode with the grid of described IGBT respectively with base stage.

This spark coil drive circuit also comprises spark coil, spark plug, spark coil comprises that the primary ignition coil of mutual coupling and secondary spark coil, spark plug are electrically connected with secondary spark coil, and primary ignition coil is connected with the drain electrode of insulated gate bipolar transistor.

When spark coil drive circuit works that the utility model provides, fire signal is by the grid input of IGBT.When fire signal is high level, the IGBT conducting, thus primary ignition coil begins to magnetize, and the electric current in the primary ignition coil begins slow increase, and the voltage at resistance two ends also increases along with the increase of electric current.When the voltage at resistance two ends reaches the conducting voltage of first triode in the protective circuit, the first triode conducting, thus making that the voltage at grid place of IGBT is zero, IGBT ends, and the electric current in the primary ignition coil reduces like this, and the voltage at resistance two ends also reduces.When the voltage at resistance two ends was reduced to the conducting voltage that is lower than first triode, first triode ended, the IGBT conducting, and the electric current in the primary ignition coil begins slow increase again.Therefore; spark coil drive circuit of the present utility model can limit the electric current of the described primary ignition coil of flowing through; prevent because of the immediate current in the primary ignition coil changes the excessive purpose that burns out secondary secondary winding thereby reached, and the protective circuit cost is low, is easy to be extensive use of.

Description of drawings

Fig. 1 is the circuit diagram of existing spark coil drive circuit;

Fig. 2 is the circuit diagram of the spark coil drive circuit that provides of a kind of mode of execution of the present utility model;

Fig. 3 is the circuit diagram according to the spark coil drive circuit of first preferred implementation of the present utility model;

Fig. 4 is the circuit diagram according to the spark coil drive circuit of second preferred implementation of the present utility model.

Embodiment

Describe the utility model in detail below in conjunction with accompanying drawing.

Fig. 2 is the circuit diagram of the spark coil drive circuit that provides of a kind of mode of execution of the present utility model.As shown in Figure 2; this spark coil drive circuit comprises IGBT P1; wherein; this spark coil drive circuit also comprises protective circuit; described protective circuit comprises the first triode T1 and resistance VR1; described resistance VR1 is connected in parallel between the base stage and emitter of the described first triode T1, and the grounded-emitter connection of this first triode T1, and the collector electrode of this first triode T1 links to each other with source electrode with the grid of described IGBT P1 respectively with base stage.This spark coil drive circuit also comprises spark coil, spark plug 3, spark coil comprises that the primary ignition coil 1 of mutual coupling and secondary spark coil 2, spark plug are electrically connected with secondary spark coil 2, and primary ignition coil 1 is connected with the drain electrode of insulated gate bipolar transistor P1.

The described IGBT P1 and the first triode T1 have constituted a negative-feedback circuit, have reached the purpose to the current limitation that magnetizes, and can the electric current that magnetize are limited in the scope of appointment by the resistance that changes resistance VR1.

IGBT P1 can select BTS2140, MGP15N40CL, NGD15N41CL etc. for use.Described first triode T1 and resistance VR1 can be that any triode and Standard resistance range are the resistance of 1-10 Ω, and for example described first triode T1 can select 9014 type triodes for use, and resistance VR1 can select the resistance of 10 Ω for use.

As shown in Figure 2, the grid of IGBT P1 is imported fire signal as fire signal input end 5, and generally speaking, described fire signal is the 5V logic gate signal that EEM system (EMS) produces.The collector electrode of the first triode T1 in the protective circuit is connected to the grid (being fire signal input end 5) of IGBT P1, and the base stage of the first triode T1 links to each other with the source electrode of IGBT P1.Like this, when fire signal is high level, IGBT P1 conducting, thus primary ignition coil 1 begins to magnetize, and the electric current in the primary ignition coil 1 begins slow increase, and the voltage at resistance VR1 two ends also increases along with the increase of electric current.When the voltage at resistance VR1 two ends reaches the conducting voltage of the first triode T1, the first triode T1 conducting, thus make that the voltage at IGBT P1 grid place is zero, and then IGBT P1 ends, electric current in the primary ignition coil 1 reduces, and the voltage at resistance VR1 two ends also reduces.When the voltage at resistance VR1 two ends is reduced to the conducting voltage that is lower than the first triode T1, the first triode T1 ends, IGBT P1 conducting, electric current in the primary ignition coil 1 begins slow increase again, and then repetition said process, form circulation thus, thereby reach the purpose of the electric current in the restriction primary ignition coil 1.

As shown in Figure 3; be first preferred implementation of the present utility model; wherein said protective circuit can also comprise first resistance R 1; second resistance R 2; field effect transistor M1; the second triode T2 and working power 8; the drain electrode of described field effect transistor M1 is electrically connected with an end of first resistance R 1 and the base stage of the second triode T2 respectively; the source ground of field effect transistor M1; the collector electrode of the second triode T2 is electrically connected with an end of second resistance R 2 and the collector electrode of the described first triode T1 respectively; the grounded-emitter connection of the second triode T2, the other end of the other end of first resistance (R1) and second resistance (R2) are connected and all are connected with working power 8.Wherein, when when work, the grid of field effect transistor M1 as fire signal input end 5, the first resistance R 1, second resistance R, 2 the other ends all are connected with working power 8, for example can be the car accumulatoies of 13V.

Described first resistance R 1, second resistance R 2, the field effect transistor M1 and the second triode T2 can be any devices that can realize above-mentioned functions, it is the resistance of 200 Ω to 2K Ω that described first resistance R 1 and second resistance R 2 can be selected resistance for use, the described second triode T2 can select 9014 for use, 803 triodes such as type such as NPN such as grade, described field effect transistor M1 can select 1A/25V for use, the M1 working power is about 13.5 volts of vehicular power-bottle voltages, therefore select operating voltage 25V, the voltage rating that surpasses far away, because M1 load resistance R1 maximum is desirable, then load current is to the maximum and is no more than 100 milliamperes, therefore selects 1A, much larger than rated current.

According to first preferred implementation, its working procedure is as follows: isolate through field effect transistor M1 from the fire signal of fire signal input end 5 input anti-phase, anti-phase through second triode T2 buffering again then, and then the conducting of control IGBT P1 and ending.For example, when fire signal is high level, field effect transistor M1 conducting, thus the current potential at Node B place is a low level, and the second triode T2 ends, and this moment, the current potential at node C place was a high level owing to drawing effect on second resistance R 2, thus control IGBT P1 conducting.And when fire signal was low level, field effect transistor M1 ended, this moment since first resistance R 1 on draw effect, thereby the current potential at Node B place is a high level, the second triode T2 conducting, the current potential at node C place is a low level, ends thereby control IGBT P1.

Because when primary ignition coil 1 is magnetized; voltage on the primary ignition coil 1 reaches the hundreds of volt; and the voltage on the secondary spark coil 2 is up to arriving several Kilovolts; high-tension late-class circuit may damage the fire signal of front stage circuits, so utilize the buffer function of field effect transistor M1 can protect fire signal well.

As shown in Figure 4, be second preferred implementation of the present utility model.Because when the second triode T2 is in cut-off state; the voltage at the grid place of IGBT P1 may be big so that damage IGBT P1; therefore; under the preferable case; as shown in Figure 4; the spark coil protective circuit that the utility model provides comprises that also the 3rd resistance R 3, the three resistance R 3 are connected in parallel between the collector and emitter of the described first triode T1.Described the 3rd resistance R 3 is divider resistances of IGBT P1 grid, and role is the control voltage that reduces the first triode T1 grid place, thereby prevents that voltage is excessive and damage IGBT P1.

Since the level of fire signal sometimes may deficiency so that field effect transistor M1 conducting, in order to improve the stability of fire signal, under the preferable case, described protective circuit comprises that also an end of the 4th resistance R 4, the four resistance R 4 is electrically connected with the grid of field effect transistor M1.When concrete the use, the other end of described the 4th resistance R 4 is electrically connected with working power 8, the effect that the 4th resistance R 4 is played is the current potential of raising fire signal.When fire signal is low level; the 4th resistance R 4 just directly is connected with ground; the current potential at basic point A place is zero; when fire signal is non-vanishing; promptly deficiency may be in so that during the unstable state of field effect transistor M1 conducting; the 4th resistance R 4 constitutes path with the circuit that produces fire signal, thereby to guarantee the current potential at basic point A place be a high level of fixing to the 4th resistance R 4.

By the spark coil protective circuit of using the utility model to provide, can be well the electric current that magnetizes of primary ignition coil be limited, and then avoid damaging secondary spark coil because of the electric current in the primary ignition coil is excessive.And employed components and parts are commonplace components in the spark coil protective circuit that the utility model provides, and cost is low, is easy to be extensive use of.

Claims

1, a kind of spark coil drive circuit; this spark coil drive circuit comprises insulated gate bipolar transistor (P1); it is characterized in that; this spark coil drive circuit also comprises protective circuit; described protective circuit comprises first triode (T1) and regulating resistor (VR1); described regulating resistor (VR1) is connected in parallel between the base stage and emitter of described first triode (T1); and the grounded-emitter connection of this first triode (T1), the collector electrode of this first triode (T1) links to each other with source electrode with the grid of described insulated gate bipolar transistor (P1) respectively with base stage.

2; spark coil drive circuit according to claim 1; it is characterized in that; described protective circuit also comprises first resistance (R1); second resistance (R2); field effect transistor (M1) and second triode (T2); the drain electrode of described field effect transistor (M1) is electrically connected with an end of first resistance (R1) and the base stage of second triode (T2) respectively; the source ground of field effect transistor (M1); the collector electrode of second triode (T2) is electrically connected with an end of described second resistance (R2) and the collector electrode of described first triode (T1) respectively; the other end of first resistance (R1) is connected with the other end of second resistance (R2), the grounded-emitter connection of second triode (T2).

3, spark coil drive circuit according to claim 2 is characterized in that, described protective circuit also comprises working power (8), is connected with the other end of first resistance (R1) and the other end of second resistance (R2).

4, spark coil drive circuit according to claim 2 is characterized in that, described protective circuit also comprises the 3rd resistance (R3), and the 3rd resistance (R3) is connected in parallel between the collector and emitter of described first triode (T1).

5, according to the described spark coil drive circuit of each claim among the claim 2-4; it is characterized in that; described protective circuit also comprises the 4th resistance (R4); one end of the 4th resistance (R4) is electrically connected with the grid of field effect transistor (M1), and the other end of the 4th resistance (R4) is connected with the other end of first resistance (R1) with second resistance (R2).

6, spark coil drive circuit according to claim 5, it is characterized in that, this spark coil drive circuit also comprises spark coil, spark plug (3), spark coil comprises that the primary ignition coil (1) of mutual coupling and secondary spark coil (2), spark plug (3) are electrically connected with secondary spark coil (2), and primary ignition coil (1) is connected with the drain electrode of insulated gate bipolar transistor (P1).

7, according to each described spark coil drive circuit among the claim 1-4, it is characterized in that, this spark coil drive circuit also comprises spark coil, spark plug (3), spark coil comprises that the primary ignition coil (1) of mutual coupling and secondary spark coil (2), spark plug (3) are electrically connected with secondary spark coil (2), and primary ignition coil (1) is connected with the drain electrode of insulated gate bipolar transistor (P1).