on Monday, 30 September 2013
LED: LED (Light Emitting Diode) is the most useful component which is used as light source. I think everyone knows about it so, no need to explain it again. 
How it looks: You can see different color variants of led's in the image below.

led symbol

How to check polarities of an LED: 

led pins

Method 1: Its very easy to know which terminal is +ve and which one is -ve. The terminal which is longer is the +ve terminal and which is shorter is -ve terminal. 
Method 2: If in case both the terminals are same, then look inside the led one which is thin is the +ve and     other one is -ve.
Method 3: If you cant find which one is thin, then use multimeter to check its polarities. Set the multimeter     in 'Continuity mode' touch the positive probe to one terminal and COM probe of multimeter to other         terminal of Led, if LED lights up then the corresponding pin is +ve and -ve. If it dint lights up then                   interchange the probes surely it will light up and corresponding pin is +ve and -ve. Even it dint lights up           then your LED is damaged one.


It consists of 4 pins lets say A,B,C,D. Two pins will be internally connected.To know which two pins are connected internally we use multimeter. Set in 'continuity mode' and touch the pins, at which contact we get beep sound they both are one pair. For example we find A&B are one pair and C&D are another pair, lets say A&B=a and C&D=b. Look at the below picture to understand.
switch on and off tutorial

When we press the switch, 'a' and 'b' will be shorted, when we left the switch it comes to its previous positions. 

PIEZO BUZZER: Buzzer is used to produce beep sound. Black wire is the -ve terminal and Red wire is +ve terminal. Operating voltage is around 1-30V i.e you can connect voltage source in this range, in general we use 5v or 9v.

In our next post we will look at how to use Bread board and wire few basic circuits on it. 


Norman Smith said...

You can use LED lights anywhere and everywhere.

Tracey Pullman said...

Many buyers are attracted to purchase long life LED lightning bulbs.

Nithan said...

The second thing that you have to do is to set down or hang up your multimeter before you will take readings. You need to ensure that a short out will happen amid the testing since it can diminish the odds of damage, especially in the cases where the multimeter does not have a circuit as security components Garage tools.

Post a Comment