What are the different ways to check LED light/bulb?
Answer Posted / chary
1. LED polarity can be checked by observing the terminals
usually longer lead is positive.
2. LED can be tested by Multimeter (digital or Analogue)
DMM should be kept in diode test mode by observing the
polarity .
meter indicates the drop ( !V to 2.7 V) depending on LED
colour . whem terminals are reversed should not indicate.
this confrms LED is good
3.When using analog multimeter keep range selector in
lowest Resistance range . in analog multimeters in
resistance mode the -ve or black wire should be treated as
+ve lead
4. LED can also be tested by connecting it to a 3v Battery /
AC adapter with a resistor(1K to 10K )connected in series
| Is This Answer Correct ? | 1 Yes | 1 No |
Post New Answer View All Answers
what is amplifier?
does capacitor requires ac or dc supply?Why?
what is an inverting amplifier?
What is 555 timer?
A good op-amp has A Very high bandwidth B Narrow bandwidth C High selectivity D All of these
hi sir i completed my b tech in ece in 2009 and i am interested in railway jobs and plz provide me with what type of questions will they ask along with model paper and my mail id is vaseem_basha@yahoo.co.in plzzzzzzzzzzzzzzz
Why is 400 hz used for flight instruments and radio transmission system in aviation industry universally?
What is the difference between fixed-bias circuit & self-bias circuit?
What are the applications of fm transceiver.
can we calculate the voltage level for microwave energy which is using for our mobile communication?
Explain conductivity?
What type of Duplexer, Multi-coupler, Trans-receiver & Combiner used in 900 & 1800Mhz
How to program micro controller?
Draw the block diagram of a 128 line EPABX and explain its operation?
What is meant by the deflection factor of a cro?