To overcome the burning of contact breaker points and production of the low spark voltage during high engine speed a Transistor is being used as a switch

1. 19A502 - AUTOMOTIVE ELECTRONICS AND ELECTRICALS
TRANSISTOR IGNITION SYSTEM
MANU KRISHNA M R
19A226

2. INTRODUCTION
● A transistor interrupts a relatively high
current carrying circuit, i.e, it controls
high current in the collector circuit
with less current in the base circuit.
● Therefore, a transistor is used to assist
the work of a contact breaker.
● Hence, this system is known as
Transistor assisted ignition system or
transistorized ignition system.
2

3. REASON FOR CHOOSING TRANSISTOR IGNITION
SYSTEM
● In conventional ignition systems, the Breaker points burns due to the High current
in the circuit.
● When Engine speed is High, the Breaker opens quickly. Leads to Low Spark Voltage.
TRANSISTOR AS A SWITCH 3

4. CONSTRUCTION
It consists of:
● Battery
● Ignition switch
● Transistor
● Contact breaker
● Ignition coil.
● Distributor and
● Spark plugs.
4

5. TYPES
There are two types of Transistor Ignition System:
1. Breaker Point Type
2. Magnetic Pulse Type
BREAKER POINT TYPE MAGNETIC PULSE TYPE 5

6. WORKING
When CB is CLOSED:
6

7. When CB is OPEN:
7

8. ADVANTAGES AND DISADVANTAGES
Advantages :
1. It increases the life of contact
breaker points.
2. It gives high ignition voltages .
3. It gives longer duration of sparks
4. It has very accurate control of
timing.
5. It needs less maintenance.
Disadvantages :
1. More mechanical points are
needed similar to a
conventional system.
2. Cost is high
8

9. 9