How do I measure the primary and secondary resistances of ignition coils?
The primary winding has fewer wires and fewer turns, which makes it very low in resistance. The secondary winding has thinner lines and more turns, thus higher resistance. The turns ratio of a car ignition coil is usually about 1:100, that is, the primary coil turns around 1 turns, and the secondary coil turns around the 100 turn. The resistance of the primary coil is usually between 1~4 ohms, and the resistance of the secondary coil is usually between 8000~16000 ohms. The additional resistor in the ignition coil low voltage circuit has the function of balancing the high voltage spark. When the current through the primary coil produce a magnetic field, the magnetic field from the start to pass into the saturation current (which reached the highest level) to experience a period of time. At low engine speeds, the magnetic field can reach saturation at high engine when time is shortened, the magnetic field cannot reach the saturation point, the secondary voltage generated will be insufficient, it will weaken the spark.
In order to increase the magnetic field, the primary coil is wound around an iron core. In this new transformer core is composed of many pieces together in the black metal (usually soft) sheet. Compared with the whole core, it has better magnetic enhancement capability.
Primary coil method. Use a multimeter diode file. A pen is a pen test column test negative column normal through the barrier is open, the secondary coil test: using a multimeter diode file. A high pressure measuring pen mouth, a pen test negative column normal through the barrier is open.
