Generally, polarity tester is done with the help of multimeter . But how we can do it without multimeter ? let see how we can do it .
In this tutorial we are going to learn simplest polarity tester with the help of two led’s and one resister
Component lists
· LED x2 — RED
· Resister -1
Devices Required:
· Soldering iron
· Holder
Circuit diagram :-
Step to follow :-
Step 1)
Connect anode of first LED to the cathode of next LED and vice versa , as shown in above circuit diagram .
Step 2)
Connect 680 ohm resister to the anode of one LED as shown in fig
Step 3)
Connect wire to other end of resister as shown in fig .
Step 4)
Connect other end to the LED as shown in fig .
Here , now it is ready to test
Working :-
When we connect our circuit to the battery or power supply . one led get forward biased and other will get reverse bias thus there is only one led get on which is near to positive terminal
