Relays

TTEC 4841 - Electrical and Electronics- Practical

24/8/2011 tuesday

start = 1.00pm finsh = 4.30pm

In todays task we started doing relays.

 first thing we did was to measure resistance which was 86 to 85 = 74.9 ohms then 30 to 87a = 0.4 ohms from 30 to 87 = 0 ohms

Then we moved on by identifing Control circuit and switching circuit.

Control circuit that switches the points : 86,85
switched points that carry the higher amps : 30,87,87a

Then we moved on calculating amps, that will flow in the control circuit 86 to 85 if 12 volts supply was used
which was   12/74.9 = 0.16 amps


Then we did our available voltage on the following terminals.

Circuit off:                   Circuit on:
86 = 12.06 v                    0.01 v
85 = 12.06 v                   12.04 v
30 = 12.06 v                   12.06 v
87a = 00 v                      12.06 v
87 = 12. 06                     0.01 v

On which terminals did the voltage change the most?

86 , 87 , 85


When the circuit is off the following terminal points 86 , 85 , 30 theres open voltage because its not using any voltage because the circuit is closed. when the circuit is on the voltage changes at the following terminals 86 , 85 , 87a because theres used voltage going to the relay and the light bulbs
At terminal 85 theres battery voltage and relay uses and theres nothing left at terminal 86.