Page 232 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

Regular

The regulator is used to control the power supply going to the battery. The regulator is fitted between the battery
and dynamo. When the speed of the engine increases, the speed of the dynamo also increases and the dynamo
generates high voltage and electric current. This may cause damage to batteries and other electrical equipment.
The regulator does the following.
• It controls voltage and current.

• It consists of a voltage regulator, a current regulator and a cut-out. Terminals are provided for dynamo and
battery. These are denoted by terminals A or D, F and B.
The following methods are adopted to control the dynamo.

• Voltage regulator system
• Current regulator system
Voltage regulator system: A voltage regulator consists of a coil of thin wire with several turns. This wire is
connected to the dynamo in parallel. It consists of an iron core, contact point, armature spring etc. The spring
holds the contact in the closed position. The voltage regulator controls the magnetic field circuit of the dynamo to
maintain the fixed voltage (12 V) output condition at 14.5 to 15 V.

When the output of the dynamo is greater than the battery voltage, the voltage flows to the solenoid winding. The
solenoid is emitted to attract the armature against the spring and
The connoisseur is isolated. Now poltage flows through the resistance in the dynamo field. Due to which there is
some voltage drop.
When there is a voltage drop in the dynamo, the solenoid becomes demagnetised. The contact spring completes
the pitch of the armature. Through the contact the voltage flows into the field winding of the dynamo. Thus, the
output voltage of the dynamo plays.

Current regulator system: Bara regulator system is installed on the basis of voltage regulator and cut-out only.
The current regulator consists of a few turns of high efficiency wire winding, connected in series with the generator
ammeter. This system is similar to the voltage control system. The electromagnet controls the contacts.
When the contact is closed and the speed of the dynamo is high, current flows through the coil of the electromagnet.
When the current is too high, the iron core becomes an electromagnet.
The armatures are attracted to separate the contacts. When the contacts open, current passes through the
resistance. This resistance creates obstruction in the flow of current.

When the value of current is relatively low, the magnetism of the electromagnet decreases, as a result of which
the contact closes again. Thus, the resistance of the field circuit gets separated from the circuit and the value of
output current in the circuit increases.

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CITS : Automotive - Mechanic Diesel - Lesson 67 - 70