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. This power passes through a capacitor and is transferred to an ignition. The design produces a multiphase spark alternating current with the first spark event negative polarity, and. How does a motorcycle capacitor discharge ignition work. 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. The 2 wires off the magneto connects directly connects to the cdi, blue to blue and black to black.
Like the magnetic pulse transistor ignition system, the cd system has a special ignition coil, a transistorized pulse amplifier, and a magnetic puke distributor. The secondary output is a short very high amplitude pulse which fires the spark plug. Multispark capacitor discharge ignition system september. Capacitor discharge ignition circuit cdi leave a reply. Capacitive discharge ignition and magnetic discharge ignition. It was originally developed to overcome the long charging times associated with high inductance coils used in inductive discharge ignition idi systems. The switch transfers the energy stored in the capacitor to the primary of the ignition coil. Simple capacitive discharge ignition cdi circuit homemade.
In a cdi ignition system,a storage capacitor is charged to a high voltage a few hundred volts by the flywheel charging coil and, at the proper moment quickly discharged into the primary winding of the ignition coil,which is actually a stepup pulsetransformer. Capacitor discharge ignition cdi coil the cdi connects to the motor to the spark plug which builds a charge and fires the plug. The vision has a revlimiter circuit that kills the front coil ignition if the tach reads over 12,000rpm. Improves engine response from low to high rpm range by supplying the ignition coil with stablized power. To solve this problem many cdi ignitions release multiple sparks at low engine speeds.
It solved the problems that had plagued earlier design attempts and became the most copied design throughout the 1960s and 1970s. 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. It comprises an ignition coil which has its primary winding connected to the battery supply with a switch at the negative side. It is similiar to full transistormagnetic control, except that certain components have been added to. Winterburn cd ignition comparison to standard kettering pointscondenser ignition winterburn kettering the winterburn capacitor discharge ignition has a long duration spark compared to other cd ignitions, but shorter than the kettering inductive ignition. View 38 best capacitor discharge ignition circuit cdi images. Many small petrol engines fitted to modern motor bikes use a capacitor discharge ignition cdi to improve performance and enhance reliability.
What links here related changes upload file special pages permanent link page. Capacitor discharge ignition using the angular timer microchip. 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. That grey wire splits somewhere under the gas tank. 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 600. Apr 20, 2017 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. Lets learn the circuit operations with the following points. The capacitor discharge ignition cdi system is an electronic ignition. The tach reads the fire pulse from the tci to the rear coil via the grey wire from the tci to the rear coil.
How capacitor discharge ignition cdi system works and its. Capacitive discharge ignition systems are the only choice for the small engines. A weak ignition can have a very fast voltage rate of rise, but the time taken for the spark to form will be longer because of the voltage. By absorbing some of the charge, the condenser allows the two contact points time to move away.
The ignition system should be mounted in a relatively cool location away from the battery under the dash is ideal. A capacitor discharge ignition system yahoo answers. It is intended particularly for use with two stroke engines, high. The switch can be a conventional set of points or a switching transistor, as used in most modern ignition systems. Capacitor discharge ignition how is capacitor discharge. This article discusses working principle of capacitor discharge ignition cdi system and its advantages and disadvantages.
Cdi ignition systems,trouble shooting,how do they work. The cdi ignition circuit produces a spark from an ignition coil by discharging a capacitor across the primary of the coil. Nowadays a more efficient and long lasting mechanism has been developed for the ignitions in vehicles, called the capacitor discharge ignition system. Thyristors problem in a 1800v capacitor discharge system. Capacitor discharge ignition system working principle a cdi system. A company was formed in ottawa in early 1963 called hyland electronics building cd ignitions using the winterburn design. They are also found frequently in racing car engine management computer. Aug 23, 2008 how to test and repair motorcycle cdi electronic ignition module coil system spark failure duration. The capacitor discharge calculator calculates the voltage that a capacitor with a a capacitance, of c, and a resistor, r, in series with it, will discharge to after time, t, has elapsed.
Capacitor discharge ignition circuit cdi circuitdb. The discharge capacitor within the cd ignition had the ability to provide a powerful spark in excess of 4 times the spark power of the kettering system using the same coil, with the exception that spark energy could be maintained at high rpm unlike the kettering system. Unfollow capacitor discharge ignition to stop getting updates on your ebay feed. May 02, 2019 simple capacitive discharge ignition cdi circuit last updated on may 2, 2019 by swagatam 222 comments 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.
A wide variety of capacitor discharge ignition options are available to you, such as free samples. This kit will replace many failed factory units and is designed for engines with separate. 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 similiar to full transistormagnetic control, except that. Signs of an auto ignition condenser going bad sapling. The short spark duration is not good for lighting relatively lean mixtures as used at low power levels. The high voltage cap at the end of the plug wire is replaceable.
Also works with msd, mallory hyfire, and other capacitive discharge boxes when using a distributor. Capacitor discharge ignition kit for motor bikes jaycar. Charging a capacitor in sereis and discharge in parallel. How to build capacitor discharge ignition circuit cdi. A schmitt trigger oscillator 74c14 and mosfet irf510 are used to drive the low voltage side of a small 12012 volt power transformer and a voltage doubler arrangement is used on the high voltage side to increase the capacitor voltage to about 340 volts. I have just modified one external link on capacitor discharge ignition. 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. Capacitor discharge ignition circuit cdi discharge ignition cdi box.
As the current climbs then so does the magnetic field in the iron core of the coil. The cdi connects to the motor to the spark plug which builds a charge and fires the plug. The capacitor discharge ignition system described in this article can be installed on any vehicle with a6v coilbreaker point ignition system. How to discharge a motor capacitor electrical wiring. The 2 wires off the magneto connect directly connects to the cdi, blue to blue and black to black. An8208 introduction to automotive ignition systems. Generic structure of capacitor discharge ignition cdi system. Information furnished is believed to be accurate and reliable. Tailored especially for vintage and classic automobiles.
What if you charged a set of, say 3, capacitors in series, then hooked them up. The 2 components that typically fry on the cdi are electrolytic capacitor because they are cheaply made and leak. The result is an intermittent connection that breaks down under the charge and discharge cycling of the capacitor. You can use this calculator to calculate the voltage that the capacitor will have discharged after a. During the second phase of the ignition cycle the capacitor is discharged through the ignition circuit. V0v1i in the case of large current discharge, it needs to consider the ir drop, which is caused during the early discharge stage derived from capacitors ir direct current resistance and the discharge current. In a capacitor discharge ignition system for an internal combustion engine wherein a controlled rectifier is periodically triggered to discharge a capacitor through the primary winding of an ignition coil, a generating and control device for periodically charging said capacitor and triggering said controlled rectifier comprising, in combination, a rotor and a stator, means for.
A capacitive discharge cd ignition consists of three main elements. Capacitor discharge calculator learning about electronics. Diy cdi capacitor discharge ignition it is the ride. How capacitor discharge ignition cdi system works and. For the future the cdi could be the solution meet the new antipollution standard requirements. An ignition condenser is a capacitor that is designed to hold a small amount of current inside the engines ignition system. A schmitt trigger oscillator 74c14 and mosfet irf510 are used to drive the low voltage side of a small 12012 volt power transformer and a voltage doubler. So this would mean it would take less time to charge, im assuming.
It was originally developed to overcome the long charging times associated with high inductance coils used in inductive discharge ignition idi. The nand gate is made of cheap transistors as wellwhile transistors are the ultimate component to be used for ultra fast switchesincoming voltage must be well regulated and without spikes. A wide variety of capacitor discharge ignition options are. While many cdi coils have just two connections, the ign1cd is one of the few cdi coils youll find in this price range to add a secondary ground connection islolating the primary side from the secondary. Diy cdi multispark capacitor discharge ignition youtube. Cdi is defined as capacitor discharge ignition very frequently. The input to the cdi unit is derived from two sources of the alternator.
Capacitive discharge ignition vs magnetic discharge ignition. Nov 27, 2015 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. The winterburn capacitor discharge ignition has a long duration spark compared to other cd ignitions, but shorter than the kettering inductive ignition. 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. Capacitor discharge ignition, capacitor discharge ignition. Winterburn and his capacitor discharge ignition published on september 21, 2015 september 21, 2015 14 likes 3 comments. Traditional ignition, as was commonplace 40 years ago, consisted of an induction coil and bre. Capacitive discharge ignition vs magnetic discharge. Referring to the above capacitor discharge ignition circuit diagram, we see a simple configuration consisting of a few diodes, resistors, a scr and a single high voltage capacitor. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple faq for additional information. In a capacitor discharge ignition system for an internal combustion engine wherein a controlled rectifier is periodically triggered to discharge a capacitor through the primary winding of an ignition coil, a generating and control device for periodically charging said capacitor and triggering said controlled rectifier comprising, in combination, a rotor and a. A capacitor discharge ignition system in a capacitor discharge ignition system, which one of the following componenets performs the same job that the breaker points do in a nonelectronic ignition system.
So putting capacitors in series decreases the capacitance of the circuit and correct me if im wrong any where in this, and im likely to be. A capacitor discharge ignition works by passing an electrical current over a capacitor. A 2uf capacitor is charged to about 340 volts and the discharge is controlled by an scr. Converting motorcycle from traditional distributor to cdi ignition system. The only downside of this is that if the cdi ignition module fails, a replacement can be very expensive. 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 breaks down again. 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. The safest way to test electrical devices and identify electric wires. The determinants of the high voltage rise time in cdi systems relate to the ignition coil parameters and the cdi unit.
No ignition system does this, so there is always voltage overshoot beyond the calibrated spark gap voltage. An automotive ignition system in which energy is stored in a capacitor and discharged across the gap of a spark plug through a stepup pulse transformer and distributor each time a silicon controlled rectifier is triggered. The capacitor discharge cd ignition system is also superior to the conventional ignition system. New cdi design provides a highenergy multispark discharge for 2stroke engines, rotaries and highperformance 4strokes.
In order to increase the engine power, economy and improve the pollution emissions, a new smart ignition system is proposed. It incorporate an electronic circuit precisely functions like the old contact breaker, but in a solidstate electronic manner. The basic operation of a kettering system shown in figure 1 is that when the contact breaker closes at time 0, the ignition coil. Ignition starter switch wiring diagram ignition wiring sensors pinout diagram dc cdi bd technical center, i have a yg6 150cc go cart with no spark i. The switch is generally linked to a diode for the reverse current. Its main purpose is to act as a ground for the electric charge to prevent the two electrodes from sparking with each other.
The capacitor discharge ignition system generates huge electromagnetic noise and this is the main reason why cdis are rarely used by automobile manufacturers. Capasitor discharge ignition ppt linkedin slideshare. Reduces resistance to battery so is ideal for vehicles equipped with additional aftermarket electronic components. This system offers several advantages over the other systems. Ignition system requirements and their application to the. The act of forming a spark is a time dependent function that takes a defined amount of energy. You can use this calculator to calculate the voltage that the capacitor will have discharged after a time period, of t, has elapsed. A basic capacitor discharge ignition system is composed of four separate components. Winterburn cdi ignition system pelican parts forums. Capacitor discharge ignition article about capacitor. The noncontact electrical tester this is a testing tool that i have had in my personal electrical tool pouch for years, and is the first test tool i grab to help identify electrical wiring.