CDI

What is a CDI System? A Discharge Ignition Capacitor is an electronic ignition device that stores an electrical charge,Then discharges it through an induction coil to supply a strong spark from theSpark plugs during a petrol engine. Charge capacitors here provide ignition. The capacitor charges and;Discharges within a fraction of your time making it possible to makeSparks CDI's are commonly found on motorbikes and scooters. Working principle a CDI System The capacitor discharge ignition process is accompanied by an electric current flowing through it.This sort of ignition builds up a charge quickly. A CDI ignition starts by generating a chargeAnd storing it up before sending it bent the sparking plug to ignite the engine. This power passes through a capacitor and is transferred to an induction coilThat helps boost the facility by acting as a transformer and,Allowing the energy to undergo it rather than catching any of it. The CDI ignition systems, therefore, allow the engine to stay running as long as there's a charge within the power source. The diagram of CDI shown below. Working of Capacitor Discharge Ignition A Capacitor Discharge Ignition consists of several partsAnd is integrated with the ignition of a vehicle. The foremost parts of a CDI include the stator,Charging coil, hall sensor, flywheel, and therefore the timing mark. Flywheel and Stator The flywheel may be a large horseshoe static magnet rolled into a circle that turns-ON the crankshaft. The Stator is that the plate holding all the electrical coils of wire,Which is employed to power ON the induction coil, bike’s lights, and battery charging circuits. Charging Coil The charging coil is one coil within the stator,Which is employed to supply 6 volts to charge the capacitor C1.Supported the flywheel’s movement the only pulsed power is producedAnd is supplied to the spark plug by the charging coil to make sure the utmost spark. Hall Sensor The Hall Sensor measures the Hall effect, the instantaneous point where the flywheel’sMagnet changes from north to the South Pole.When the pole change occurs, the device sends one,Tiny pulse to the CDI box which triggers it to dump the energy from the charging capacitor into the high voltage transformer. Click on the second page to read the rest of the article. Timing Mark The timing mark is an arbitrary alignment point shared by the engine case and stator plate.It indicates the purpose at which the highest of the piston’s travel is like theTrigger point on the flywheel and stator. By rotating the stator plate left and right,You effectively change the trigger point of the CDI,Thus advancing or retarding your timing, respectively. Because the flywheel turns fast,The charging coil produces an AC from +6V to -6V. The CDI box features a collection of semiconductor rectifiers that connected toG1 on the box allows only the positive pulse to enter the capacitor (C1).While the wave getting into the CDI, the rectifier allows only the positive wave. Trigger Circuit The trigger circuit may be a switch, probably employing a Transistor,Thyristor or SCR. This triggered by a pulse from the Hall Sensor on the stator.They only allow current from one side of the circuit until they're triggered. Once the Capacitor C1 is fully charged, the circuit is often triggered again.This is often why there's timing involved in the motor. If the capacitor and stator were perfect,They might charge instantaneously and that we can trigger them as fast as our wish. However, they require a fraction of a second to full charge. If the circuit triggers too fast,Then the spark from the sparking plug is going to be enormously weak. Certainly, with the upper accelerating motors,We may have the triggering faster than the capacitor full charge,Which can affect performance?Whenever the capacitor is discharged,Then the switch turns itself off and therefore the capacitor charges again. The trigger pulse from the Hall sensor feeds into the gate latch and allows all the stored charge to rush through the first side of the high-voltage transformer. The transformer features a footing between the first and secondary windings, referred to as an autotransformer. Therefore, as if we increase the windings on the secondary side, you'll multiply the voltage. Since a sparking plug needs an honest 30,000 volts to sparks,There must be many thousands of wraps of wire round the high voltage or secondary side. When the gate opens and dumps all the present into the first side,It saturates the low-voltage side of the transformer and sets up a brief but immensely magnetic flux. Because the field reduces gradually,An outsized current within the primary windings forces the secondary windings to supply extremely high voltage. However, the voltage is now so high that it can arc through the air,So instead of being absorbed or retained by the transformer,The charge travels up the plug wire and jumps the plug gap. When we want to pack up the motor engine, we've two switches the key switch or the kill switch. The switches ground out the charging circuit, therefore, the entire charging pulse is shipped to the bottom. Since the CDI can not charge,It'll cease to supply the spark and therefore the engine will slow to a stop. Advantages of CDI The major advantage of CDI is that the capacitor can be fully charged in a very short time (typically 1ms). So the CDI is suited to an application where the insufficient dwell time is available.The capacitor discharge ignition system has a short transient response, a fast voltage rise (between 3 to 10 kV/ µs) compared to inductive systems (300 to 500 V/ µs) and shorter spark duration (about 50-80 µs).The fast voltage rising makes CDI systems unaffected to shunt resistance. Disadvantages of CDI The capacitor discharge ignition system generates huge electromagnetic noise and this is the main reason why CDIs are rarely used by automobile manufacturers.The short spark duration is not good for lighting relatively lean mixtures as used at low power levels. To solve this problem many CDI ignitions release multiple sparks at low engine speeds. Read More: Car Battery Or Alternator: Which One Is The Culprit Behind A Dead Car?Are you an ignition expert? Take the quiz!How To Tell If Starter Relay Is Bad? Four Common SymptomsCommon Spark Plug Misfire SymptomsDifference Between SI engine and CI engine If the nose of the plug is not hot enough, It will gradually accumulate deposits, Known as fouling. During normal engine operation, Residue from the combustion process hits the insulator nose. This may include carbon, unburned fuel, and oil, And chemical additives present in both fuel and oil. If the insulator nose and electrodes are hot enough, The combustion deposits will be continuously burned off by the heat of the plug. The ideal situation is to have the deposits burned off as fast as they accumulate, So, the insulator nose stays fairly clean and free of deposits. If the deposits accumulate on the plug because it is not reaching a high enough temperature to burn them off, The gradual accumulation will eventually short out, or foul, the plug. The fouling is electrically conductive and forms a path along the insulator, Which connects the center electrode to the metal shell of the plug.

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Capacitor-Discharge Ignition(CDI) Working Principle, Its Advantage and Disadvantage