HEAD 1038361 - Caterpillar

Internal electronic regulators
Illustration 25 g01073337
Internal alternator regulators are mounted either inside or outside of the slip ring end housing of the alternator. This type of regulator eliminates the wiring harness between the alternator and regulator simplifying the system. This type of regulator is usually much smaller than other types and uses electronic circuits known as integrated circuits or ICs. ICs are miniaturized electronics with much of the circuit on one small chip. Integral regulators perform the same function as the external electronic regulators.Some alternators with integral regulators have only one wire that is going to the regulator. This wire is the alternator output wire. The ground circuit is completed through the housing to the engine block. Current for the integral regulator is fed from the stator through a diode trio. The alternator starts charging by using the small amount of permanent magnetism in the rotor. This small amount of output is fed back into the field which increases the output. This continues until full output that is determined by the regulator is reached.Regulator Circuits
Illustration 26 g01073339
There are two basic field circuit connections for an alternator A circuit and B circuit. An A type circuit alternator (Illustration 26) uses two insulated brushes in the alternator. One brush is connected directly to the battery, while the other brush is connected to ground with the regulator and ignition switch or relay in series. The regulator is located after the field, between the field and the alternator ground or negative diodes. Full alternator output is obtained by grounding the field windings. Some alternators have a tab in a test hole so that the field is grounded by placing a screwdriver against the tab end and the alternator frame. This type of circuit is used with integral regulators and some external electronic regulators.
Illustration 27 g01073340
B type circuits use a brush that is grounded inside the alternator (Illustration 27). The other brush is connected to the battery in series with the regulator and the ignition switch or the relay. In a B circuit alternator the regulator is located before the field. The current flow is usually from the regulator terminal of the alternator to the regulator. After the regulator, the current flows to the field coil in the rotor, then to ground, and finally to the negative or return diode assembly. Full alternator output is obtained by connecting the field terminal to the regulator terminal or the output terminal.Charge Indicators
Illustration 28 g01073341
Charge indicators may be an ammeter, a voltmeter or a charge indicator light. Ammeters may be installed in series if the ammeters are full current, shunt type, or in parallel if the ammeter is the nonshunt type.Voltmeters are more commonly used because they more accurately indicate the operation of the system. Voltmeters can be easily installed in parallel with the charging system. Voltmeters provide information on both the operation of the charging system and condition of the battery.Charge indicator lights show general system operation. Charge indicator lights will not indicate high alternator output or high voltage