Silicon chip microprocessor controlled dwell pg 33. A capacitor discharge ignition works by passing an electrical current over a capacitor. Capacitive discharge ignition cdi is sometimes also known as thyristor ignition. An8208 introduction to automotive ignition systems. The battery powers the dccdi module which consists of a small transformer, a charging circuit, a triggering circuit and a main capacitor. An819 application note 211 capacitor the capacitor between 0. During the second phase of the ignition cycle the capacitor is discharged through the ignition circuit.
Traditional ignition, as was commonplace 40 years ago, consisted of an induction coil and bre. The following post describes a simple yet enhanced 12v capacitive discharge ignition system which derives its operating voltage from the battery instead of the alternator for generating the igniting sparks. A capacitor discharge ignition system for a jet engine which has a relatively high power factor at the transformer input without exceeding the one ampere current rating required in jet ignition systems at the desired power level. Capacitor discharge ignition electronic ignition system will prolong life of points and plugs on older cars and insure easier cold starts by bill noble, santa monica, california while we all recognize the desirability of a 100% stock vehicle, an electronic ignition can greatly ease the problems of starting an older vehicle as well as prolonging. What are the 3 major differences between a capacitor. Capacitor discharge ignition cdi system the cdi system has been widely used in motorcycles, lawn mowers, and other small engines. See other formats ignition system requirements and their application to the design of capacitor discharge ignition systems terrence lyle wmliamson naval postgraduate school monterey, california thesis ignition system requirements and their application to the design of. Capacitor discharge ignition system working principle a cdi system.
May 06, 2018 in cdi system also called as capacitor discharge ignition system, a capacitor is charged by a power source and then discharged through the primary coil of ignition coil so that high voltage is. Light speed engineering has introduced a new ignition system to its line of products. Upon applying a direct current potential across the input terminals of a conventional dc to dc inverter circuit, the inverter power transistors begin oscillating, thereby driving the primary of the inverter transformer which produces a high. May 02, 2019 in this post we discuss the circuit for a simple, universal capacitive discharge ignition circuit or a cdi circuit using a standard ignition coil and a solid state scr based circuit. It is available in the internet archives open library, and has a wealth of detail information on designing power inverters including transformer core steel selection pages 302 to 338 and specifically on capacitive ignition systems pages. Ignition system testing, magneto coils, points and cdi. Pdf a multi spark discharge ignition mode with a single capacitor for a two stroke airassisted direct injection spark ignition engine fueled with. It should be installed in such a way that when it is removed, the car is again stock.
The result is an intermittent connection that breaks down under the charge and discharge cycling of the capacitor. The winterburn capacitor discharge ignition system was the very first commercially successful solidstate cd ignition designed by the late lloyd winterburn rcaf electronics expert and pilot in 1962. A small engine ignition includes the ignition controller mechanicalbreaker, capacitor discharge, or transistorcontrolled, spark plugs, flywheel, and wiring. The prior art capacitor discharge ignition system also includes appropriate switching means which is controlled by the usual breaker, or its equivalent, and which serves to cause a capacitor to charge to the voltage of the inverter when the breaker points are closed, and to apply its energy to the ignition coil when the breaker points are opened. This early type of ignition design is known as the kettering system points condensercoil or induction system. Understanding what the cdi is and how it works can. Msd digital 6a and 6al ignition control 6a pn 6201, 6al. Here is how to test the ignition magneto coils found on all types of motorcycle engines, points or cdi. Its used to produce energy but in the battery case, it wasnt. Capacitive discharge ignition for two wheelers international. Capacitive discharge digital ignitions store charged energy for the spark in a capacitor within the module that can be released to the spark plug at virtually any time throughout the engine cycle via a. In capacitor discharge ignition, a capacitor charged to a high voltage is switched across the primary of the ignition coil to generate a spark impulse.
Application note an4006 freescale semiconductor, inc. Capacitor discharge ignition cdi, capacitor and the lowinductance ignition coil used in cdi systems, the spark duration is relatively short, and protection schemes higher reliability inductive discharge ignition. Full text of ignition system requirements and their application to the design of capacitor discharge ignition systems. An advantage of the capacitor discharge ignition system is that the energy storage and the voltage step up functions are accomplished by separate circuit elements allowing each one to be optimised for its job. Capacitor discharge ignition system download pdf info publication number. In this study, four ignition systems, namely, stock capacitive discharge ignition cdi, laser ignition, flame jet ignition fji, and nanopulse delivery npd ignition were tested using a. The msd ignition features a capacitor which is quickly charged with 520 535 volts and stores it until. Altronic ii for large gas engines, 320 cylinders altronic ii provides a selfpowered, capacitor discharge system for largebore, slowspeed gas engines.
This was the ignition system used in most cars in the 20th century up until the advent of electroni. In cdi system also called as capacitor discharge ignition system, a capacitor is charged by a power source and then discharged through the. The capacitor discharge cd ignition system is also superior to the conventional ignition system. In cdi, a storage capacitor is charged with high voltage stepped up from a cars charg ing system. This completely new capacitor discharge ignition system has been designed from the ground up to provide a high energy multiple spark discharge to cope with engines which have very high rpm rates. Digital electronic ignition modules can be designed as either capacitor discharge ignition cdi or inductive discharge ignition idi systems. The capacitor discharge ignition system described in this article can be installed on any vehicle with a 6v coilbreaker point ignition system. An ignition system provides a highvoltage spark in the engines cylinders to ignite the airfuel mixture.
Google has not performed a legal analysis and makes no. The ignition process in any vehicle becomes the heart of the entire system as without this stage the vehicle just wont start. It is rugged and reliable but has drawbacks as you will see. Unfollow capacitor discharge ignition to stop getting updates on your ebay feed. Capacitor discharge ignition cdi or thyristor ignition is a type of automotive electronic ignition system which is widely used in outboard motors, motorcycles, lawn mowers, chainsaws, small engines, turbinepowered aircraft, and some cars. Compared to the inductive discharge mechanism in idi systems, cdi system uses capacitor discharge current to fire the spark plug. Hawthorne 19641967 comments about kettering ignition system. The pickup coil must generate an ac voltage pulse to the ignition module so that the module can pulse the ignition coil. The capacitivedischarge ignition uses capacitor di. Practical efforts to improve or supplant this system have failed, and it has remained virtually unchanged through the years.
Servicing the ignition system of your small engine depends on which types of components it has. When the engine of the system starts, it helps magneto to rotate and thus its producing the energy in the form of high voltage then, one end of the magneto is grounded through contact breaker, and the ignition capacitor is connected to its parallel. Pdf design and experiment of multi spark capacitor. Capacitor discharge ignition cdi or thyristor ignition is a type of automotive electronic ignition system which is widely used in outboard motors, motorcycles.
A cdi ignition starts by generating a charge and storing it up before sending it out to the spark plug in order to ignite the engine. Cdi capacitor discharge ignition circuit demo youtube. Testing for a spark on many classic bikes consists of laying the plug on top of the cylinder head connected to the plug cap and ht lead and turning the engine over with the ignition on. In this post we discuss the circuit for a simple, universal capacitive discharge ignition circuit or a cdi circuit using a standard ignition coil and a solid state scr based circuit. The capacitor discharge ignition system described in this article can be installed on any vehicle with a6v coilbreaker point ignition system.
Heathkit model cp 1060 capacitive discharge ignition page 2. It was originally developed to overcome the long charging times associated with high inductance coils used in inductive discharge ignition systems, making the ignition system more suitable for high engine speeds. Mar 27, 2003 a capacitor discharge ignition cdi system is capable of generating intense continuous electrical discharge at a spark gap for a desired duration and may include a second controllable power switching circuit with its input terminal connected to an output terminal of a high voltage dc source device. How does a motorcycle capacitor discharge ignition work. Adler december 1971 reproduced by national technical information service springfiold. In an inductive ignition, the coil must store and step up the voltage. Simple capacitive discharge ignition cdi circuit homemade. Kettering 11 august 191117 april 1917 ignition system points, no capacitor, ignition switch to avoid draing the battery.
Full text of ignition system requirements and their. Variableratio electronically controlled oil injection, 200 dfi models, oil injection system. Capacitor discharge ignition fault finding made easy. The cdi box is the heart of a motorcycles ignition system, containing a series of diodes and semiconductors that amplify the 12volt current supplied by the motorcycles battery between a 400 to 600volt range.
Jun 26, 2019 the circuit of an enhanced capacitive discharge ignition circuit which is discussed here, eliminates the use of the alternator voltage for functioning, instead it utilizes the battery voltage for generating the required actions. What seems to happen is when the capacitor is operating in an ignition system the current surge causes a temporary weld of the connection, and when the capacitor sits unused the connection. Lowcost industrial system capacitor discharge, highenergy spark accurate timing crankshaftreferenced no moving parts eliminates distributor 1224 vdc powered builtin diagnostics cdi is a capacitor discharge, electronic microcircuitbased ignition system for small 1 to 8 cylinder industrial engines. How capacitor discharge ignition cdi system works and. A pickup coil contains a coil of wire, and the resistance of this coil should be within the range specified by the manufacturer. In the world of small motor, such as mopeds or lawn movers the ignition system design is based exclusively on cdi 1. Ignition in lean fuel mixtures by capacitor discharge systems can sometimes only be accomplished by the use of multispark ignition, where the ignition system duplicates the prolonged spark of inductive spark systems by sparking a number of times during the cycle. Digital capacitive discharge ignition system, capacitive discharge ignition cdi system for twowheelers, and outlines a solution using motorola, motorcycles, and mopeds, commonly use an engine ignition system based on the capacitive discharge method, known as capacitive discharge.
Capacitive discharge ignition vs magnetic discharge. The majority of stock ignition systems are inductive ignitions. Car ignition circuits contain devices which can produce very high voltages in excess of 10kv that could be hazardous to your. Naval postgraduate school monterey, california i jun 9 1972 b b thesis ignition system requirements and their application to the design of capacitor discharge ignition symtems by terrence lyle williamson thesis advisor. Like the magnetic pulse transistor ignition system, the cd system has a special ignition coil, a transistorized pulse amplifier, and a magnetic puke distributor. Capacitor discharge ignition fault finding made easy above is a schematic of a basic cdi ignition system, it can be broken down in to the following components. Comparative analysis of engine ignition systems request pdf. Capacitive discharge the digital 6a and 6al feature a capacitive discharge ignition design. The general structure of an idi system is shown in figure 3. However, a dva measurement of this same ac voltage would reveal that the peak of the ac sine wave is typically between 160. Capacitor discharge ignition or thyristor ignition is a type of automotive electronic ignition system which is widely used in outboard motors, motorcycles, lawn mowers, chainsaws, small engines, turbinepowered aircraft, and some cars. Heathkit model cp 1060 capacitive discharge ignition. Capacitor discharge ignition system cdi system youtube. A simple electronic circuit using a large storage capacitor and a thyristor silicon control rectifier provides a correctly.
It is available in the internet archives open library, and has a wealth of detail information on designing power inverters including transformer core steel selection pages 302 to 338 and specifically on capacitive ignition systems pages 678 to 692. A kettering ignition system uses a capacitor, points, ignition coil and spark plugs to ignite the gasair mixture in an internal combustion engine. See other formats ignition system requirements and their application to the design of capacitor discharge ignition systems terrence lyle wmliamson naval postgraduate school monterey, california thesis ignition system. May 01, 2018 a kettering ignition system uses a capacitor, points, ignition coil and spark plugs to ignite the gasair mixture in an internal combustion engine. The new plasma iii capacitor discharge system is the latest high performance ignition for all 4cyl and 6cyl aircraft engines. The cdi system uses highvoltage capacitor discharge current output to fire the spark plug. When working with cdi type ignition systems, it is very important to be aware of the high voltage discharge from the spark plug. The systems simplicity and long record of field reliability have made it the ignition of choice for operators of lowhorsepower industrial engines. Like the magnetic pulse transistor ignition system, the cd system has a special ignition coil, a transistorized pulse amplifier, and a. Altronic ii can be used on engines with either one or two spark. A capacitor discharge ignition system as set forth in claim 3 in which said charge coil and ignition coil are wound on one portion of said core wherein the coils are subject to the same changes in magnetic flux throughout the range of operation of said system. Authority us united states prior art keywords capacitor discharge voltage energy storage circuit prior art date 19560301 legal status the legal status is an assumption and is not a legal conclusion.
Capacitor charging and discharging occurs very quickly typically 1ms, leading to a short duration, high energy spark. Capacitor discharge ignition kit for motor bikes jaycar. An improved capacitor discharge ignition system which produces controlled multiple ignition sparks for each opening of the distributor breaker points. Electronic 12v dc capacitive discharge ignition cdi. Generic structure of capacitor discharge ignition cdi system compared to the mechanical ignition system, the modern electronic ignition system has the following advantages. An example would be that the typical rms ac reading of a wall outlet in north america is 120v. Source coil, trigger or pulsar coil, kill switch, ht coil and ignition unit. Hero motocorp implemented the capacitor discharge ignition technology in hero hf deluxe while bajaj employs it in its discover bike. The only downside of this is that if the cdi ignition module fails, a replacement can be very expensive. Tailored especially for vintage and classic automobiles. The typical turbine engine is equipped with a capacitor type, or capacitor discharge, ignition system consisting of two identical independent ignition units operating from a common lowvoltage dc electrical power source. This completely new capacitor discharge ignition system has been designed from the ground. It is intended particularly for use with two stroke engines, high performance four strokes and older vehicles. Cdi ignitions provide the engine with powerful, reliable power and require very little maintenance.
The ignition system should be mounted in a relatively cool location away from the battery under the dash is ideal. How to repair a smallengine ignition system how to. A highenergy capacitor discharge ignition system this completely new capacitor discharge ignition system has been designed from the ground up to provide a high energy multiple spark discharge to cope with engines which have very high rpm rates. A capacitor discharge ignition is an electronic ignition device that stores an electrical charge and then discharges it through an ignition. Capacitive discharge ignition vs magnetic discharge ignition.
Lower longterm cost through reduced maintenance higher and more consistent ignition energy more robust less volume and weight. With four different internal gear ratios, base or flange mounting, and three drive coupling choices, altronic ii can be readily specified to replace most older magneto or breakerpoint ignition systems. Most motorcycles built after 1980 use a capacitor discharge ignition system to power their engines, replacing the older pointstype mechanical contact breaker ignition. Its long duration spark and optimized timing curve makes more horsepower and improves fuel efficiency at all altitudes. Many small petrol engines fitted to modern motor bikes use a capacitor discharge ignition cdi to improve performance and enhance reliability. A basic capacitor discharge ignition system is composed of four separate components. Car ignition circuits contain devices which can produce very high voltages in excess of 10kv that could be hazardous to your health especially if you have an implantable electronic device such as a pacemaker or defibrillator.
Capacitive discharge ignition systems work by storing energy in an external capacitor, which. It became the standard in the automotive industry replacing magnetos. The capacitor discharge ignition cdi system is an electronic ignition system used in internal combustion engines. Generic structure of capacitor discharge ignition cdi. Capacitive discharge ignition systems are the only choice for the small engines. An1980 capacitor discharge ignition using the angular timer. How capacitor discharge ignition cdi system works and its. A highenergy capacitor discharge ignition system based on an article by silicon chip septermber 199 7 this completely new capacitor discharge ignition system has been designed from the ground up to provide a high energy multiple spark discharge to cope with engines which have very high rpm rates. It is intended particularly for use with two stroke engines, high. Sep 12, 20 cdi capacitor discharge ignition circuit demo. For the future the cdi could be the solution meet the new antipollution standard requirements. They are also found frequently in racing car engine management computer.
1178 686 314 124 1497 1127 1150 837 1571 296 607 744 562 1420 168 522 1359 77 1373 935 332 1246 937 1194 569 819 1270 92 1422 957 1466 1447 1342 593 1303 1380 1220 634 770 534 1095