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Fig. 363.- View of Packard Twin Six Motor Showing Location of Generator and Starting Motor; Also
Depicts How Compactly Parts May Be Arranged at the Side of the Engine Crank Case. The Special Delco Twin Six Ignition Unit is Shown at the Front of the Engine.
Ignition Unit with
Extension of Pu.aip Shaft
Om Protective anitt Circuit
Dw Cells for Reserve Ignition
Frame of Car
Fig. 364.–The Delco One Unit Starting, Lighting and Ignition System, armature makes twenty revolutions to turn the engine over once, and assuming a motor speed of 2,000 R.P.M., the engine will be cranked over 100 R.P.M., or considerably faster than is possible by hand.
When the unit is generating current for charging the battery it is a simple shunt wound generator. In this case it is driven from the engine by an extension of the pump shaft. The generator is driven at crank shaft speed and in order to compensate for the higher ratios when the unit is in starting relation to the engine a second one-way driving clutch is provided adjacent to the forward housing. This permits the armature to run ahead of the driving shaft during the cranking operation. When a starting pedal is pushed forward it shifts the brushes from the generator commutator and engages the brushes of the motor commutator, there being two commutators on the armature. Whenever the starting pedal is released the motor brushes are lifted from their commutator and generator brushes are dropped on their commutator.
A cut-out relay is located on the rear end housing of the motor generator, this instrument performing a double function. During the initial starting operation it is closed mechanically to complete the circuit between the storage battery and the armature, and it also automatically closes the circuit between the generator and storage battery when the generator voltage is high enough to charge the battery. It opens the circuit when the generator slows down to prevent the battery discharging back through the generator windings. The latest type Delco system has a slightly different detail construction of the generator than those formerly used as it has a “third brush” inherent regulation of current output instead of an auxiliary voltage regulator.
Q. Describe the latest type Delco motor generator and its functions.
A. The motor generator which is located on the right side of the engine as at Fig. 365 is the principal part of the Delco System. This consists essentially of a dynamo with two field windings, and two windings on the armature with two commu-' tators and corresponding sets of brushes. In order that the ignition apparatus incorporated in the forward end of the machine may work when it is used as a starting motor, or as a generator for charging the battery and supplying the liglits, horn and ignition, the ignition distributor is always driven in the same direction.
This in no way affects the working of the generator, it being mounted in this
Fig. 365.-Application of Delco Motor Generator to 1916 Hudson Engine.
manner simply as a convenient and accessible mounting. cases it is independent.
The motor generator has three distinct functions to perform which are as follows: No. 1–Motoring the Generator. No. 2– Cranking the Engine. No. 3-Generating Electrical Energy.
Q. Describe the "motoring" function.
A. Motoring the generator is accomplished when the ignition button on the switch is pulled out. This allows current to come from the storage battery through the ammeter on the combination switch, causing it to show a discharge. The first reading of the meter will be much more than the reading after the armature is
Fig. 366.—Diagrams Explaining Construction of Delco Motor Generator
Having Third Brush Current Control.
turning freely. The current discharging through the ammeter during this operation is the current required to slowly revolve the armature and what is used for the ignition. The ignition current flows only when the contacts are closed, it being an inter