阅读说明：本技术 一种基于cdi点火发动机的转速采集电路 (Rotational speed acquisition circuit based on CDI ignition engine ) 是由 李勇 李彦霖 李柏婵 于 2019-11-25 设计创作，主要内容包括：本发明涉及发动机技术领域,具体为一种基于CDI点火发动机的转速采集电路,包括主电路和控制所述主电路短路与导通的控制电路；所述控制电路包括信号隔离单元,用于隔离CDI点火产生的原始信号中主干扰源并输出为采集电路的控制信号；模拟电压,用于为所述控制电路和主电路提供模拟信号输入；开关元件,用于根据控制信号和模拟信号输入以控制主电路的短路与导通；所述主电路包括采集元件,用于根据主电路的短路与导通输出采集信号。本发明采用二极管、三极管和光电耦合器等元件的配合,能有效隔断原始信号的主干扰,提高采集系统的稳定性和可靠性,且电路结构简单、成本低廉,具有响应速度快和适用范围广的优点。(The invention relates to the technical field of engines, in particular to a rotating speed acquisition circuit based on a CDI ignition engine, which comprises a main circuit and a control circuit for controlling the short circuit and the conduction of the main circuit; the control circuit comprises a signal isolation unit, a control unit and a control unit, wherein the signal isolation unit is used for isolating a main interference source in an original signal generated by CDI ignition and outputting the main interference source as a control signal of the acquisition circuit; the analog voltage is used for providing analog signal input for the control circuit and the main circuit; a switching element for controlling short circuit and conduction of the main circuit according to the control signal and the analog signal input; the main circuit comprises an acquisition element for outputting an acquisition signal according to the short circuit and the conduction of the main circuit. The invention adopts the matching of elements such as a diode, a triode, a photoelectric coupler and the like, can effectively isolate the main interference of the original signal, improves the stability and the reliability of the acquisition system, and has the advantages of simple circuit structure, low cost, high response speed and wide application range.)

1. A rotational speed acquisition circuit based on CDI ignition engine which characterized in that: the circuit comprises a main circuit and a control circuit for controlling the short circuit and the conduction of the main circuit;

the control circuit includes:

the signal isolation unit is used for isolating a main interference source in an original signal generated by CDI ignition and outputting the main interference source as a control signal of the acquisition circuit;

an analog voltage (5) for providing an analog signal input to the control circuit and the main circuit;

a switching element (3) for controlling the short circuit and conduction of the main circuit according to the control signal and the analog signal input;

the main circuit comprises:

and the acquisition element (4) is used for outputting an acquisition signal according to the short circuit and the conduction of the main circuit.

2. A CDI ignition engine based speed acquisition circuit as claimed in claim 1, wherein: the signal isolation unit is a first diode (2A) with the negative electrode connected with the CDI to ignite and generate an original signal.

3. A CDI ignition engine based speed acquisition circuit as claimed in claim 1, wherein: the switch element (3) is an NPN triode.

4. A CDI ignition engine based speed acquisition circuit as claimed in claim 3, wherein: the control circuit also comprises a base electrode biasing resistor (1E) and a collector electrode biasing resistor (1D) which are respectively connected with the base electrode and the collector electrode of the triode and used for providing biasing voltage for the triode.

5. A CDI ignition engine based speed acquisition circuit as claimed in claim 3, wherein: the control circuit further comprises a first voltage dividing resistor (1B) and a second voltage dividing resistor (1C) for dividing the analog voltage (5).

6. A CDI ignition engine based speed acquisition circuit as claimed in claim 1, wherein: the acquisition element (4) is a nonlinear photoelectric coupler.

7. The CDI ignition engine-based speed acquisition circuit of claim 6, wherein: the main circuit also comprises a protection element which is connected with the photoelectric coupler in series and is used for avoiding reverse breakdown of the triode on the secondary side of the photoelectric coupler.

8. A CDI ignition engine based speed acquisition circuit as claimed in claim 2, wherein: the signal isolation unit is connected with a first current limiting resistor (1A) in series for avoiding reverse breakdown of the signal isolation unit.

9. A CDI ignition engine-based speed acquisition circuit as claimed in claim 7, wherein: the protection element comprises a second diode (2B) or a second current limiting resistor (1F) or a combination thereof for limiting the current of the main circuit.

10. The CDI ignition engine-based speed acquisition circuit of claim 6, wherein: and the emitter of the secondary triode of the photoelectric coupler is grounded through a third current limiting resistor (1G).

Technical Field

The invention relates to the technical field of engines, in particular to a rotating speed acquisition circuit based on a CDI ignition engine.

Background

The oil-driven unmanned helicopter has strong cruising ability, and is convenient and time-saving to add fuel. The operating state of the engine determines whether the unmanned aerial vehicle can safely and reliably operate, wherein the rotating speed of the engine directly influences the control and performance parameters of the helicopter. Therefore, the problem of detecting and acquiring the rotating speed of the engine in real time is the first problem to be solved by the unmanned aerial vehicle control system.

At present, in an oil-driven helicopter, a common method for collecting the rotating speed of an engine is that a magnetic bead is arranged on a radiating fan of the engine or a transmission shaft of the engine, a Hall proximity switch is fixedly arranged near the transmission shaft, the gap between the switch and the magnetic bead is 2-15mm, the magnetic bead cuts a magnetic induction line along with the rotation of the transmission shaft of the engine, the Hall switch generates a pulse, and the pulse period is in direct proportion to the rotating speed, so that the rotating speed of the engine is measured.

The Hall components and parts are installed complicatedly, and because the clearance is small, the risk of safety and pulse loss exists, and the requirement of accurately acquiring the rotating speed in real time cannot be met. CDI ignition is a common ignition mode for engines, and the above problems can be effectively solved by processing the signal by using periodic pulse information generated by CDI ignition of the engine.

Disclosure of Invention

The invention aims to provide a rotation speed acquisition circuit based on a CDI ignition engine, so as to solve the problems in the background technology.

The above object of the present invention is achieved by the following technical solutions:

a rotational speed acquisition circuit based on a CDI ignition engine comprises a main circuit and a control circuit for controlling short circuit and conduction of the main circuit;

the control circuit includes:

the signal isolation unit is used for isolating a main interference source in an original signal generated by CDI ignition and outputting the main interference source as a control signal of the acquisition circuit;

the analog voltage is used for providing analog signal input for the control circuit and the main circuit;

a switching element for controlling short circuit and conduction of the main circuit according to the control signal and the analog signal input;

the main circuit comprises:

and the acquisition element is used for outputting an acquisition signal according to the short circuit and the conduction of the main circuit.

Preferably, the signal isolation unit is a first diode with a negative electrode connected with the CDI to ignite and generate an original signal.

Preferably, the switching element is an NPN transistor.

Preferably, the control circuit further comprises a base electrode bias resistor and a collector electrode bias resistor which are respectively connected to the base electrode and the collector electrode of the triode and used for providing bias voltage for the triode.

Preferably, the control circuit further includes a first voltage dividing resistor and a second voltage dividing resistor for dividing the analog voltage.

Preferably, the collecting element is a nonlinear photocoupler.

Preferably, the main circuit further comprises a protection element connected in series with the photoelectric coupler and used for avoiding reverse breakdown of a triode on the secondary side of the photoelectric coupler.

Preferably, the signal isolation unit is connected in series with a first current limiting resistor for avoiding reverse breakdown of the signal isolation unit.

Preferably, the protection element includes a second diode or a second current limiting resistor or a combination thereof for limiting a current of the main circuit.

Preferably, an emitter of the secondary triode of the photoelectric coupler is grounded through a third current limiting resistor.

Compared with the prior art, the invention provides a rotating speed acquisition circuit based on a CDI ignition engine, which has the following beneficial effects: the original signal generated by CDI ignition has the defects of large level fluctuation and strong interference. The invention adopts the matching of elements such as a diode, a triode, a photoelectric coupler and the like, can effectively isolate the main interference of the original signal, improves the stability and the reliability of the acquisition system, and has the advantages of simple circuit structure, low cost, high response speed and wide application range.

Drawings

Fig. 1 is a rotation speed acquisition circuit according to an embodiment.

In the figure: 1A, a first current limiting resistor; 1B, a first divider resistor; 1C, a second divider resistor; 1D, a collector bias resistor; 1E, a base electrode bias resistor; 1F, a second current limiting resistor; 1G, a third current limiting resistor; 2A, a first diode; 2B, a second diode; 3. a switching element; 4. a collection element; 5. and simulating a voltage.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.