The main principle of transistorized ignition systems is to use transistors as electronic switches instead of breaker points. For those of you who already know about vehicle ignition systems, you should know the breaker point or platinum. Breaker point is a device used to break the primary coil current in the ignition coil so that electromagnetic induction can occur. This breaker point works mechanically by utilizing a cam that can stretch the breaker point gap.
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The main principle of transistorized ignition systems is to use transistors as electronic switches instead of breaker points. For those of you who already know about vehicle ignition systems, you should know the breaker point or platinum.
Breaker point is a device used to break the primary coil current in the ignition coil so that electromagnetic induction can occur. This breaker point works mechanically by utilizing a cam that can stretch the breaker point gap. However, the use of breaker points is considered to be less effective, it is because the rubbing components will erode so that it can affect the overall ignition system performance. In addition, when the breaker point is stretched, frequent sparking occurs at the breaker point so that the induction power of the ignition coil is reduced.
By utilizing transistors the two things above can be overcome. Why are transistors used instead of breaker points? As we said at the beginning, the transistor has a function as an electronic switch.
There are three legs on the transistor namely base, collector, and emitter. Collector is input, while emitter is output. The base as a controller, if there is an electric current low voltage flows at the base then the current at the input collector will flow to the output emitter. However, when the electric current at the base stops, the collector is cut off again with an emitter. So in conclusion, the transistor can be used in the ignition system because of its characteristics that can disconnect and connect lines quickly.
To control the performance of the transistor, we need one additional sensor, the pick up coil. This sensor will send a low-voltage current with pauses according to the ignition timming at the base foot.
So that the transistor performance will be matched with the engine RPM. How does the coil pick up work? Pick up coil consists of three parts, namely rotor with cam, permanent magnet and coil. The three components are placed as shown, it is confirmed that the permanent magnet emits a magnetic field that hits the rotor.
While the rotor is made of metal which is able to be attracted by magnets. Cam on the rotor serves to shorten the gap between the rotor with a permanent magnet. This changing gap causes the current in the pickup coil to be zig-zag. When the cam is parallel to the permanent magnet there is an electric current, but when the cam shifts the current disappears.
This drop voltage is used as timming to break the primary current in the ignition coil. Transistorized Ignition System diagram.
Transistorized Ignition System Working and Diagram
To obtain the maximum power and speed that this engine can produce, you must install an ignition system that outperforms the conventional one. Electronic type of ignition systems provide a hotter, more uniform spark at a more precise interval. The increased reliability of electronic ignition allows less frequent maintenance by increasing parts life. At high speeds, the breaker points of a conventional ignition system cannot handle the increased current flowing across them without pitting too much. Also, the dwell angle of the breaker points is too small for complete saturation of the ignition coil. The transistorized ignition system takes care of both drawbacks.
The electrical system provides for low current through the breaker points to minimize wear and corrosion of the breaker points, provides a high primary winding current at saturation of the primary winding and of the transistors of the electrical system to provide a strong spark, and has a minimum of components. The system includes first and second compound-connected transistors with the base of the second transistor being connected to the emitter of the first transistor and the collectors of said transistors being connected to ground potential. A voltage dividing circuit is adapted to be connected in series with the breaker points of a distributor between the emitter of the second transistor and the breaker points. The base of the first transistor is connected to a predetermined point in the voltage dividing circuit; and the emitter and collector of the second transistor are adapted to be connected in series with the primary winding of an ignition coil and a source of electric potential. Cook, P. Box , Melrose Park, Primary Examiner-Laurence M.
What is FTIS – Fully Transistorised Ignition System?
The overall objective of the new Delcotronic Transistor-Controlled Magnetic Pulse-Type Ignition System the official name was to provide long life, high reliability, and require no periodic maintenance during the life of the vehicle. A brief review of the limitations of the conventional breaker-point system are: The available voltage to fire a spark plug cannot be increased due to the limited current carrying capabilities of the points. Periodic ignition system service is required due to rubbing block wear and point erosion. Distributor point bounce places a practical limit on the engine speed of which satisfactory ignition performance can be maintained.