Subject: Automobile Engineering

Topic: Electrical System, Starting Systems & Alternator

Difficulty: Low

In the Voltage regulator, there is shunt coil a dynamo & a resistor & also a pair of contact points. When the voltage of the dynamo goes beyond a cartain limit, the control points open. Immediately, the resistance comes into action. Now, the voltage output is reduced. When this happens, the points once again come into contact with each other. The value of the voltage of the dynamo now again increases. In this way, the contact points open & close many times every second. Actually, the contact points are vibrating. This is how the voltage regulator functions.

Continuous current & Voltage regulator:
Fig 13.1 shows various parts of the regulator. It consists of the cut out relay, current regulator, dynamo & field coil. When dynamo(a) is started , the voltage builds up. When sufficient voltage is reached, the cut-out relay comes into action. By this, armature(4) is pulled towards the soft iron core of the cut-out relay. This gives a corrention between the dynamo & battery.

When the dynamo starts running at a higher speed, The voltage regulator immediately comes into action. Armature(6) is pulled away from the contact points of the voltage regulator . The contact points are now opened. Point resistance(7) is then introduced in the field coil, thereby bringing down the voltage.

1) cut-off relay
2) current regulator
3) voltage regulator
4,5,6) armature
7) Point resistance
8) swamp resistance
9) Dynamo
10) Field coil.