CONDENSER ACTION:

The functions of the ignition condenser are to reduce the amount of arcing across the points thereby preventing excessive metal transfer from one point to the other and to quickly stop the flow of current in the primary coil winding so that the maximum voltage can be generated in the secondary coil winding.

The condenser can store a certain amount of energy. Then the breaker points open and the induced voltage in the coil tries to keep current flowing across the breaker points, the condenser will absorb the electrical energy until the breaker points have opened sufficiently so that an arc cannot occur. By the time the condenser becomes fully charged, the points have opened too far for arcing to take place.

By preventing the arc from occurring across the breaker points, the condenser brings the primary current flow to a sudden stop. This causes a very sudden collapse of the magnetic field, so that the lines of force cut through the windings in the coil with great speed. The voltage induced in the secondary winding forces current to jump the spark plug gap. The charge in the condenser surges back in a reverse direction through the primary circuit across the battery and builds up on the opposite plate of the condenser. The condenser then discharges in the opposite direction and charges the condenser once more in the original direction. Each time the condenser discharges, part of the energy is lost in overcoming the resistance of the circuit so that the oscillating current will die out, or nearly so, before the contact points close for the next build up.

CONDENSER TESTING AND SELECTION:

Condensers are tested for resistance, capacity and leakage. The resistance test reveals the presence of any loose or high resistance connection in the pigtail or the case. The capacity test checks the microfarad capacity of the condenser. The insulation test stresses the insulating material with about 500 volts while the tester meter indicates the presence of current leakage through the insulation. A condenser that tests defective in any test must be replace.

The testing of a used condenser will reveal the presence of any defects but it cannot measure the amount of useful life left in the condenser. For this reason it is advisable to always install a new condenser when replacing the breaker points.

Some transfer of metal from one breaker point to the other is a normal action that occur in all ignition systems. The function of a condenser of correct capacity is to prevent any excessive metal transfer. The capacity of the condenser is an important specification. It has been selected to match the particular requirements of a given ignition system. When replacing the condenser be sure that new condenser has the microfarad capacity recommended in the specifications.

Typical specifications are:   0.18 – 0.23 mfd ; 0.21 – 0.25 mfd ;  0.25 – 0.285 mfd.

When a good condenser of the correct capacity is employed and a condition of excessive point metal transfer nevertheless exists, the condition may be due to:

·         Excessive primary or secondary circuit resistance in the ignition system which will upset the system balance.

·         A high voltage regulator setting which causes increased primary current flow resulting in everlasting and burning of the breaker points.

·         Incorrect breaker point dwell angle.

·         Continual high speed operation.

·         Frequent periods of prolonged idling.

Locating and servicing the cause of the trouble will prevent a reoccurrence of the condition. In the case of the last two conditions, more frequent tune-ups should be recommended.