Ignition system requirements and their application to the. Phys e1bthe physics of the automotive ignition system spring 2008 3 set up the pasco function generator as in figure 2 to give you an onoff step voltage square wave output and apply this to the primary of the coil with a 4. The ignition pulse waveform can be controlled to predetermined actual ignition requirements. The regular software and driver updates are a real bonus. On the primary winding side of the ignition coil this induced voltage has the reverse polarity to. Figure 1 is the waveform observed on an oscilloscope placed across the. The use of a large capacitor, charged by prior ignition event. In modern transistor ignition systems, where the transistor replaces the points, a capacitor on coil is not used. Kettering ignition system primary voltage and current waveforms. The final voltage is about 12 volts 2 volts lower than the original voltage. Assessment requirements for auretr031 diagnose and. The primary will draw a couple of amps or more especially if the connection is not broken, the primary will short out your dc adapter if the primary connection is not broken. Costeffective 8 channels oscilloscope for vehicle testing.
Secondary waveform the condition of the coil, the coil lead to the distributor, the distributor cap and rotor, the spark plug leads and the plugs. It comprises an ignition coil which has its primary winding connected to the battery supply with a switch at the negative side. Ever wondered how the ignition system generates a spark. Here i am checking the voltage on the control side of an ignition coil, i am also showing the current ramps of that same ignition coil. Biography of charles kettering, inventor of the electrical. It produces a verylongduration ignition pulse with an energy in the order of 100 inillijoules. These snapon scopes have a maximum displayable voltage of 200 volts, as you. Ignition systems are well known in the field of internal combustion engines such as those used in petrol gasoline engines used to power the majority of motor vehicles. A pickup coil contains a coil of wire, and the resistance of this coil should be within the range specified by the manufacturer. It is true that in the kettering system, a capacitor is placed in parallel with the. The invention of the electric starter motor by kettering eliminated the need for hand cranking. The selfstarting ignition was first installed in a cadillac on february 17, 1911.
Kettering ignition systems used on the majority of automotive engines can. The delco ignition system, also known as the kettering ignition system, is a type of inductive discharge ignition system invented by charles f. Until the recent challenges to improve fuel efficiency and reduce polluting emissions, it has been sufficient for most applications. And when the mood strikes you to scope secondary ignition, keep in mind that secondary waveforms look a lot like primary waveforms. A sustainedarc ignition systein has been developed for internal combustion engines. The kettering points type of ignition used a distributor as a mechanical switch to turn the primary circuit on and off. Well, heres the automotive waveform database software to the rescue. Ignition primary and secondary voltage waveforms should really be taken at the beginning of a throttle snap as this when the ignition is stressed most. The secondary coil has a high ratio of windings to the primary coil. The basic operation of a kettering system shown in figure 1 is that when the contact breaker closes at time 0, the ignition coil.
So basically it is a ignition coil driver circuiti want to improve the output. I dont see any controls on your scope to invert te waveform which is a pain but i have a couple inverted wave forms from different scopes. If the oscilloscope voltage setting is lowered to magnify the bottom of the ignition primary coil waveform, the voltage drop can be seen more clearly waveform segment d in the upper pane of fig. The battery is the source of electrical energy needed to operate the ignition system. This arrangement creates conditions of high mutual inductance, meaning changes in the magnetic field in the primary coil will produce changes in voltage in the secondary coil. The spark source is a lowvoltage magneto, with a 1. Distributor based ignition systems use a single ignition coil. Ignition system is divided into two electrical circuits the primary and secondary circuits. Some primary ignition systems have a voltage signal which peaks at over 400 volts. When the coils primary circuit is switched on, the voltage drops slightly, and as the current in the circuit increases to the target of 11 amps, the voltage drops accordingly.
The usual defect pointed out in the standard kettering ignition system is that fact that at high range rpms there is less time available to store magnetic energy in the field of the ignition coil, so the spark energy drops off at high range rpms. When the primary circuit of an ignition transformer, or spark coil, is opened, the sudden change in. Capacitive discharge ignition vs magnetic discharge ignition. The kettering system is the least expensive system currently available and is todays industry standard. Cop ignition testing with the paddle probe and pico scope quickie vid duration. The purpose of this test is to examine primary ignition voltage on an external. A modern igbt transistor has only a few hundred pf of capacitance, a value much less than a points capacitor. Ignition system requirements and their application to the design of capacitor discharge ignition systems by terrence lyle williamson lieutenant, united states naval reserve b. An ignition coil consists of a primary coil and a secondary coil, wound around each other in close proximity.
All current electronic ignition systems including coil on plug designs found on modern direct injection. The ats ecop attaches to the coil housing or ignition wire capturing a clear ignition waveform. A secondary ignition circuit consists of three components and is the basis for newer variations of the ignition system. You will see that picoscope has displayed an example waveform and is preset to capture your waveform. Once the current rises to the point of full coil saturation magnetic field not in movement, the magnetic field completely surrounds the secondary windings. The primary circuit is between the battery and the ignition coil. Primary ignition vs secondary ignition for distributor systems. The first electrical ignition system or electric starter motor for cars was invented by general motors gm engineers clyde coleman and charles kettering. An arm with a set of contacts was controlled by a small cam inside the distributor to control the current from the ignition coils primary circuit. The secret to being able to capture and analyze secondary ignition waveforms is understanding what is happening in the coil and at the spark plug, and how the. Idle speed control valve waveforms rotary and electromagnetic ignition waveforms primary secondary injector waveforms knock sensor lambda oxygen sensor lin bus waveforms map sensor road speed sensor rpm sensor starter current cranking amps stepper motor tdc sensor throttle potentiometer waveform library contents courtesy of pico. Atsfreeground ignition waveforms can identify engine drivability problems, but modern coil on plug cop systems have module drivers built into them so they have no primary waveform.
Use the waveform buffer, zoom and measurements tools to examine your waveform. Secondary ignition autoditex automotive diagnostic tools. Anyone here who can help me with my little project. You can check many of the vital signs of these components by looking at the highvoltage secondary waveform. Assessment requirements for auretr031 diagnose and repair ignition systemsdate this document was generated. Kettering ignition system an internal combustion engine requires a source of energy to ignite the fuelair mixture in the cylinder at the right time. In a conventional kettering ignition system, which uses breaker points to interrupt the current flowing in the primary coil, it is the value of the primary current, the dwell time during which the breaker points are closed, and the speed with which the breaker points open that controls the voltage of the secondary coil. Capacitive discharge ignition vs magnetic discharge.
Scoping and interpreting secondary ignition waveforms. Hantek 1008c pc usb 8ch automotive diagnostic digital. Use the aes primary ignition lead with the vantage pro, modis, and verus to see the primary ignition spikes that rise higher than 200 volts while maintaining the option to zoom in on essential details such as the dwell, burn time and coil oscillations. The rising current in the ignition coil primary has an inverted exponential profile. The battery stores and produces electricity through chemical action. Over time, this system was used extensively by all automobile and truck manufacturers until the development of capacitor discharge ignition electronic ignition. Viewing the primary ignition pattern requires that you have to monitor the voltage signal on the negative side of the coils primary circuit and to identify the trigger. It is loaded with hundreds of different waveforms, many of them with field. The secondary circuit is between the ignition coil and the spark plug. This voltage drop can be seen as the slight rise at the bottom of the primary waveform. Home made secondary ignition multi cylinder probe youtube.
The ignition coil s sat32 may 2005 understanding ignition waveforms. An ignition system is a system for igniting a airfuel mixture. Full text of ignition system requirements and their. Automobiles that used the kettering ignition system included a resistor in series with the ignition coil to limit the current draw when the 1 the car was idling or 2. I have inhand some ignition coils from an old naturalgas powered, 6 cyl, industrial stationary engine that i am try to get running.
The switching of the primary circuit can be controlled using one of two mechanisms. Functions of condenser in pointstype ignition system. Primary igniton circuits how to test pico technology pico auto. Handheld oscilloscope hantek2d82auto 4 in 1 multifunction. Hei interfacedriver module with auto dwell switch control pg 32. This model is for conventional kettering ignition i. As the current climbs then so does the magnetic field in the iron core of the coil. This video is an extract from the automate ignition systems kettering type training module. The switch can be a conventional set of points or a switching transistor, as used in most modern ignition systems. It was first sold commercially on the 1910 cadillac and was manufactured by delco. In a diesel engine, the rapid compression of the inlet charge raises its temperature to the point of selfignition, hence the alternative name, compressionignition engine. Primary igniton circuits how to test pico technology. A leaky condenser will reduce ignition performance.
Primary ignition lead for snapon modis, verus, vantagepro. Assessment requirements for auretr031 diagnose and repair ignition systems date this document was generated. Secondary ignition waveforms and analysis garage lube. The ignition system is typically controlled by a key operated ignition switch. The pickup coil must generate an ac voltage pulse to the ignition module so that the module can pulse the ignition coil. The average driver cannot operate in a range that will best prevent. But that highvoltage waveform also is affected by combustion inside the cylinder. The kettering system became the primary ignition system for many years in the automotive industry due to its lower cost, and relative simplicity. The aes primary ignition probe adapter is designed specifically for the uscope and for testing primary ignition. It is important to understand the information you can read in the waveform, seeing the. Install the pc software and start to use without any other drivers.
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