PHILBRIN SINGLE SPARK IGNITION SYSTEM
OPERATION, ADJUSTMENT AND CARE
The Philbrin ignition system consists of a specially designed contact
maker and interrupter, a distributor mounted on the same shaft, a
nonvibrating heat and moisture proof coil, an armored heat, moisture,
and puncture proof condenser, and a special Duplex switch.
[Illustration: Fig. 80. Philbrin Contact Maker--Point Adjustment]
Fig. 80 shows an illustration of the Philbrin contact maker which
operates in this manner. The cam A strikes against the end of the
plunger B and forces the points together at C, and holds the contact
for approximately three and one-half degrees of the revolution of
the cam. The spark occurs simultaneously with the separation of the
contact points. The contact maker has but one adjustment; that of the
adjustable contact screw, which is in direct line with the contact
plunger. The contact points are brought together gradually by the
surface formation of the cam. When the point of ample saturation of the
coil is reached, the breaking of the contacts is instantaneous. The
duration of the spark is in proportion to the speed of the engine, but
breaking of the points is always instantaneous and entirely independent
of the engine’s speed thereby producing the required spark at all
speeds without any spark lag.
[Illustration: Fig. 81. Philbrin Contact Maker and Distributor Blade]
Fig. 81 shows the distributor blade mounted over the contact maker. The
distributor blade is so arranged that it clears the spark plug lead
terminals in the cover by a slight margin, and does not make actual
contact, thereby eliminating all friction due to such contacts.
=Operation.=--Turning on the switch sets up a low tension current in
the coil and primary wire coil when the contact points close. The
sudden breaking of this current causes demagnetism of the core and the
primary coil to set up a high tension current in the secondary coil.
This current is led to the distributor blade and passes to the spark
plug terminals as the blade comes in contact range.
The Philbrin high frequency system uses the same coil and distributor
as the single spark system. But as the circuits of the two systems are
entirely distinct and separate, they do not conflict with each other.
The high frequency system has its own condenser and interrupter located
in the switch case, and supplies a continuous flow of sparks.
[Illustration: Fig. 82. Switch Case]
Fig. 82 shows the interior of the switch case. This part of the
mechanism controls the interruption of the battery current. The current
is supplied to the interruptor through a polarity reverser, which
reverses the direction of the current each time the switch button is
turned. This equalizes the wear on the contact points.
Attention is again called to the distributor blade shown in Fig.
82, which is used for both systems. Because of the shape of this
blade, there is a continuous flow of sparks after the explosive
spark has been delivered to one cylinder until the forward edge of
the distributor blade is within range of the distributing point of
the next terminal. By this action the first spark delivered to the
cylinder is an efficient one, and the follow up continues at intervals
of approximately one-thousandth of a second. These sparks are all
perfectly synchronous.
The operation of the high frequency system does not differ in function
action from the single spark system explained on the foregoing page.
Either system may be had singly, or in duplex formation. Consequently
either the single or the double system may be encountered. When the
duplex system is used the driver has his choice and can use either
the high frequency or single spark system, by turning the rubber roll
switch on the distributor to the system indicated.
This follow-up feature has been found particularly advantageous
for starting in cold weather, or where a poor grade of gasoline is
encountered, and in case of a poor carburetor adjustment or foul spark
plugs. The high frequency system also has the unique feature of keeping
the spark plugs clean without disintegrating the electroids, as is
often the case with the high tension magneto.
[Illustration: Fig. 83. Duplex High Frequency Switch]
Fig. 83 shows the Duplex switch. Ordinarily a storage battery is used
for one source of current, and a set of dry cells for the other. This
is so arranged that either source of current can be used with either
the single spark system or the high frequency system at will. One
source of current only can be used if so desired, that is, the storage
battery only or the dry cells alone. Where the source of current
is dry cells only, the single spark system is used as it is more
economical in current consumption. All of the switch contacts are of
the pressure plunger type, thereby eliminating the uncertainty of brush
contacts. Each switch is provided with a lock operating through the
hub of the lever. When the switch is locked in the off position it is
impossible to remove the cover without breaking it as the cover of the
switch locks to the back.
Ratchet buttons select which one of the systems is to be used, by a
movement of 45°. This button operates only in a clock-wise direction.
[Illustration:
C-2 Circuit 2
C-1 Circuit 1
Bat.-1 Battery 1
Bat.-2 Battery 2
Sec.-Secondary
C-Circuit
Sec. Gr. Secondary Ground
To Spark Plugs
BAT. (SEC.) C
( GR.)
BAT.-2
BAT.-1
Coil
C.R.
Distributor
Fig. 84. Philbrin Wiring Diagram]
Fig. 84 shows a wiring diagram of the Philbrin system. The wire
connections come to the contact maker directly from the switch, instead
of from the coil. This provides for control of the current to the
contact maker in such a manner that if a short circuit occurs in either
of the systems, by turning a button it is entirely cut off and the
other system put into operation.
Tungsten contact points are used on the single spark system as they are
not effected by the use of light oil. The contact points for the high
frequency system are platinum-iridium. They are mounted inside of the
switch case and need little or no attention. The contacts, due to the
reversed polarity, have an extremely long life and can be used without
attention until they are worn down to the base metal. The duel type
of system, however, may be purchased in separate units, and an owner
may choose either the high frequency system or the single spark system
separately if so desired.
This type of ignition system is manufactured for four, six, eight, and
twelve cylindered cars.