CN103676737B - A kind of digital frequency conversion charge/discharge control circuit and realize the method for frequency conversion - Google Patents

Abstract

The present invention provides a digital frequency conversion discharge control circuit and a method for realizing frequency conversion. It combines digital chips such as 8-bit preset synchronous decrement counter CD40103 and MC14536 programmable timer to adjust and configure the high and low levels of CD40103B counter J0-J7. , to change the preset value of the counter, so that by counting the number of discharges, when the number of discharges reaches the preset value, the fourteenth pin of the CD40103B counter outputs a frequency conversion signal to change the output frequency of the discharge frequency generator MC14536 to achieve the purpose of frequency conversion; The frequency conversion time and discharge frequency can be precisely adjusted by adopting the above technical scheme. Since the digital signal has strong anti-interference ability, the adjustment is simple and reliable, and it has a certain effect on improving the discharge continuity and reliability of the pulse device.

Description

A digital frequency conversion discharge control circuit and a method for realizing frequency conversion

technical field

The invention relates to a discharge control circuit of a pulse device, in particular to a digital frequency conversion discharge control circuit and a method for realizing frequency conversion.

Background technique

The ignition device, which is an important part of the engine ignition system, is a pulse generator. The ignition device has gradually developed from the transistor self-excited type to the digital ignition device. The discharge frequency of the ignition device also develops from instability to stability. The ignition device converts low-voltage direct current into high-voltage pulse electricity (above kilovolts). Working at high frequency for a long time, the components in the ignition device will generate a lot of heat, which is easy to burn the components and affect the life of the ignition device. The ignition device generally works continuously for dozens of seconds. When the engine is difficult to start in harsh environments, the ignition system needs to provide continuous electric sparks to ignite the air-fuel mixture in the engine combustion chamber. Therefore, it is necessary to study a control circuit that can change the discharge frequency. After the device has been working for a period of time, the discharge frequency can be changed to reduce the discharge frequency of the device and increase the life of the ignition device.

Contents of the invention

The problem to be solved by the invention is to provide a digital frequency conversion discharge control circuit applied to a pulse device and a method for realizing frequency conversion. The circuit design is based on an 8-bit preset synchronous decrement counter CD40103B, which can monitor the discharge frequency and count by subtraction. When the preset value is reached, the frequency conversion signal is output to achieve the purpose of frequency conversion of the discharge frequency.

In order to solve the above technical problems, the technical solution adopted by the present invention is: a digital variable frequency discharge control circuit, including a counter, an inverter and a NOR gate circuit; a programmable timer and a MOS transistor Q1; an inverter string Connect to the frequency division configuration pin of the programmable timer; the output discharge signal of the programmable timer is connected to one input terminal of the NOR gate, and the variable frequency signal output pin of the counter is connected to the other input terminal of the NOR gate; The output terminal is connected to the clock pin of the counter; the frequency conversion signal output by the counter is divided into two channels, one is connected to the logic input pin of the programmable timer, and the other is connected to the gate of the MOS transistor Q1; the input pins of the programmable timer are connected in series A second resistor R2 is connected to the source of the MOS transistor Q1, the first output pin of the programmable timer is connected in series with a capacitor C1 and the second resistor R2, and then connected to the source of the MOS transistor Q1, the second output of the programmable timer The pin is connected in series with a first resistor R1 and then connected to the drain of the MOS transistor Q1.

Further, the counter is a CD40103B chip.

Further, the programmable timer is MC14536 chip.

Further, the inverter is connected in series between any two pins of the ninth pin, the tenth pin, the eleventh pin and the twelfth pin of the MC14536 chip; the thirteenth pin of the MC14536 chip The output discharge signal is connected to one input terminal of the NOR gate, and the fourteenth pin of the CD40103B chip is connected to the other input terminal of the NOR gate; the output terminal of the NOR gate is connected to the first pin of the CD40103B chip; the first pin of the CD40103B chip The frequency conversion signal output by the fourteen pins is divided into two channels, one is connected to the input terminal of the inverter, and the other is connected to the gate of the MOS transistor Q1; the third pin of the MC14536 chip is connected in series with a second resistor R2 and then connected to the gate of the MOS transistor Q1 Source, the fourth pin of the MC14536 chip is connected in series with a capacitor C1 and the second resistor R2 and then connected to the source of the MOS transistor Q1, and the fifth pin of the MC14536 chip is connected in series with a first resistor R1 and then connected to the drain of the MOS transistor Q1.

Using the above digital variable frequency discharge control circuit to achieve frequency conversion, configure the high and low levels of the J0-J7 pins of the CD40103B chip to set the preset value (adjusting the high and low levels of the J0-J7 pins configured with the CD40103B chip can change the counter preset setting value); by counting the number of discharges, when the number of discharges reaches the preset value, the fourteenth pin of the CD40103B chip outputs a frequency conversion signal, and the fourteenth pin changes from high level to low level; the allocation of the MC14536 chip When the true value code of the configuration pin changes, the oscillation frequency of the peripheral circuit configuration changes accordingly, and the discharge frequency generated and output by the MC14536 chip changes accordingly, realizing frequency conversion.

The advantages and positive effects of the present invention are: combining digital chips such as 8-bit preset synchronous decrement counter CD40103 and MC14536 programmable timer, adjusting the high and low levels of CD40103B counter J0-J7 to change the counter preset value, so that the number of discharges can be counted. When the number of discharges reaches the preset value, the fourteenth pin of the CD40103B counter outputs a frequency conversion signal to change the output frequency of the discharge frequency generator MC14536 to achieve the purpose of frequency conversion; the above technical solution can be accurately Adjusting the frequency conversion time and discharge frequency, due to the strong anti-interference ability of the digital signal, the adjustment is simple and reliable, and it has a certain effect on improving the discharge continuity and reliability of the pulse device.

Description of drawings

Fig. 1 is the circuit principle diagram of this digital frequency conversion discharge control circuit.

detailed description

The technical solutions created by the present invention will be further described in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, the inverter is connected in series between any two pins of the ninth pin, the tenth pin, the eleventh pin and the twelfth pin of the MC14536 chip; the tenth pin of the MC14536 chip The three-pin output discharge signal is connected to one input terminal of the NOR gate, and the fourteenth pin of the CD40103B chip is connected to the other input terminal of the NOR gate; the output terminal of the NOR gate is connected to the first pin of the CD40103B chip; The frequency conversion signal output by the fourteenth pin of the CD40103B chip is divided into two channels, one is connected to the input terminal of the inverter, and the other is connected to the gate of the MOS transistor Q1; the third pin of the MC14536 chip is connected in series with a second resistor R2 and then connected to The source of the MOS tube Q1, the fourth pin of the MC14536 chip is connected in series with a capacitor C1 and the second resistor R2 and then connected to the source of the MOS tube Q1, the fifth pin of the MC14536 chip is connected in series with a first resistor R1 and then connected to the MOS tube Q1 the drain. The programmable timer MC14536 in the frequency conversion control circuit is used to generate and output the discharge frequency, and the capacitor and resistor are connected in parallel between pin 4 and pin 5 of the programmable timer of MC14536 to configure the initial oscillation frequency.

The ninth and tenth pins of the MC14536 chip are connected to the input of the inverter, and the other pins are connected according to the configuration requirements of the peripheral circuit of the chip.

The discharge signal of the MC14536 chip and the fourteenth pin of the CD40103B counter are respectively connected to the input terminal of the NOR gate, and the output terminal of the NOR gate is connected to the first pin of the CD40103B counter, and the frequency conversion signal of the fourteenth pin of the CD40103B counter is output to the MOS tube The gate of Q1 and the input terminal of the inverter configure the high and low levels of the CD40103B counter J0-J7 to set the counter preset value. When the discharge times reach the preset value, the fourteenth pin of the CD40103B counter outputs a frequency conversion signal , the fourteenth pin of the counter changes from high level to low level. At this time, the true value code of the distribution configuration pin of the MC14536 programmable timer changes, and the oscillation frequency of the peripheral circuit configuration also changes accordingly. In this way, the MC14536 The generated and output discharge frequency changes accordingly to achieve the purpose of frequency conversion.

According to the above description of the circuit implementation method, in order to achieve a flexible choice of frequency conversion design method, you can only change the initial oscillation frequency of MC14536, or only change the frequency division configuration pin of MC14536, or combine the two methods to obtain more fine frequency adjustment. .

Compared with the prior art, the digital variable frequency discharge control circuit applied to the pulse device can prolong the working time of the pulse device, realize continuous and stable ignition, and the adjustment is simple and reliable.

The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and cannot be considered as limiting the implementation scope of the present invention. All equal changes and improvements made according to the creative scope of the present invention should still belong to the scope covered by this patent.

Claims (5)

1. A digital variable frequency discharge control circuit, including a counter, an inverter and a NOR gate circuit; it is characterized in that: it also includes a programmable timer and a MOS transistor Q1; the inverter is connected in series with the frequency division configuration of the programmable timer pin; the output discharge signal of the programmable timer is connected to one input terminal of the NOR gate, and the frequency conversion signal output pin of the counter is connected to the other input terminal of the NOR gate; the output terminal of the NOR gate is connected to the clock pin of the counter; The frequency conversion signal output by the counter is divided into two channels, one is connected to the logic input pin of the programmable timer, and the other is connected to the gate of the MOS tube Q1; the input pin of the programmable timer is connected in series with a second resistor R2 and then connected to the MOS tube The source of Q1, the first output pin of the programmable timer is connected in series with a capacitor C1 and the second resistor R2, and then connected to the source of the MOS transistor Q1, and the second output pin of the programmable timer is connected in series with a first resistor R1. Connect to the drain of MOS transistor Q1. 2. The digital variable frequency discharge control circuit according to claim 1, characterized in that: the counter is a CD40103B chip. 3. The digital variable frequency discharge control circuit according to claim 2, characterized in that: the programmable timer is an MC14536 chip. 4. The digital variable frequency discharge control circuit according to claim 3, characterized in that: the inverter is connected in series with the ninth pin, the tenth pin, the eleventh pin and the twelfth pin of the MC14536 chip Between any two pins; the thirteenth pin of the MC14536 chip outputs the discharge signal to one input of the NOR gate, and the fourteenth pin of the CD40103B chip is connected to the other input of the NOR gate; the NOR The output terminal of the gate is connected to the first pin of the CD40103B chip; the frequency conversion signal output by the fourteenth pin of the CD40103B chip is divided into two channels, one is connected to the input terminal of the inverter, and the other is connected to the gate of the MOS transistor Q1; the MC14536 chip The third pin of the MC14536 chip is connected in series with a second resistor R2 to the source of the MOS transistor Q1, the fourth pin of the MC14536 chip is connected in series with a capacitor C1 and the second resistor R2 and then connected to the source of the MOS transistor Q1, and the fifth pin of the MC14536 chip The pin is connected in series with a first resistor R1 and then connected to the drain of the MOS transistor Q1. 5. Utilize the method for realizing frequency conversion by the digital variable frequency discharge control circuit as claimed in claim 3, characterized in that: the high and low levels of the J0-J7 pins of the CD40103B chip are configured to set preset values; count the discharge times, when the discharge times reach When the preset value is set, the fourteenth pin of the CD40103B chip outputs a variable frequency signal, and the fourteenth pin changes from high level to low level; the true value code of the distribution configuration pin of the MC14536 chip changes, and the oscillation of the peripheral circuit configuration The frequency changes accordingly, and the discharge frequency generated and output by the MC14536 chip changes accordingly, realizing frequency conversion.