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Suresh R
03/24/06 05:36
Read: 953 times
Chennai
India


 
#112959 - (.2*bulb resistance
Responding to: Terry Lingle's previous message
Terry Lingle said:

bulb voltage will be approximatly (.2*bulb resistance at that current) that resistance is fillament temperature dependant and must be determined from the dreaded data sheet for the bulb selected.

When the current flow is .18A (i.e.,the current required for the bulb) the resistance would be 66.66R
So when i calculate the bulb voltage it gives = .2 * 66.66 = 13.332 V. so i dont know how connecting a 12V supply could achieve this. Did i took it wrongly?

Terry Lingle said:

In that case the transistor will see the remaining voltage across its c-E junction thus the potential dissapation issue.

iam some what familiar in calculating the Vce and Ve.
But since it is a bulb load i could not asses how much would be the drop accross the bulb, which i would need to know to calculate the dissiation accross Vce.

I think the bulb i used was from a local manufacturer.
I couldnt get any data regarding it other than the rating.
So as you say going through a datasheet of a particular bulb would prove useful.
can any one get me one.

Terry said:
It seems that you are a little light in the fundamentals of electronics and could benifit from some extra curricular work. Can anybody recomend a suitable basic text easily available in India


The books i refer gives not much examples on driving different types of loads nor it is that descriptive at some cases. i think the book "Art of Electronics" would be useful as a reference material which i would try to get it in few days.
I have found it being preferred during some discussion here and also heard with my friends also.

Thanking you,
Suresh.




List of 57 messages in thread
TopicAuthorDate
inrush current + suitable voltage sour      Suresh R      03/04/06 10:14      
   Inrush current of lamp      Kai Klaas      03/04/06 20:47      
      Current inrush      Hal Albach      03/05/06 06:28      
         NTC?      Jan Waclawek      03/05/06 06:45      
            Soft-start      Kai Klaas      03/05/06 08:00      
               8 reed SW parallely + 21.12A / at 12VDC      Suresh R      03/06/06 05:29      
                  Car battery???      Anders Sandström      03/06/06 05:58      
                  inrush current      Terry Lingle      03/06/06 08:20      
                  totally irrelevant      Erik Malund      03/06/06 08:58      
                  No testing needed, standardly      Kai Klaas      03/06/06 19:46      
                     replies      Suresh R      03/07/06 02:05      
                        Reply to "replies"      Kai Klaas      03/07/06 07:29      
                           the difference between "cheap" and "inex      Erik Malund      03/07/06 07:44      
                           current limit resistor      Suresh R      03/07/06 09:17      
                              are you just grasping for straws?      Erik Malund      03/07/06 09:29      
            NTC, yes      Erik Malund      03/06/06 08:54      
               Filaments      Kai Klaas      03/06/06 18:38      
                  In the days of radios for AC and DC      Erik Malund      03/07/06 06:57      
                     Thanks      Kai Klaas      03/07/06 07:03      
            resistor parallel to Switch!      Suresh R      03/11/06 04:29      
               MOSFET, constant current source?      Kai Klaas      03/11/06 07:04      
                  not for my use      Suresh R      03/11/06 09:24      
                     Ok, but...      Kai Klaas      03/11/06 10:00      
                        but i think      Suresh R      03/11/06 10:25      
                           Relays      Kai Klaas      03/11/06 10:51      
                              yes ofcourse      Suresh R      03/11/06 11:46      
                                 here we go again        Erik Malund      03/13/06 06:57      
                                    Even more!!      Kai Klaas      03/13/06 07:14      
                                       werlcome to the club      Erik Malund      03/13/06 07:18      
                                       reply      Suresh R      03/13/06 10:49      
                                          why did you not say so?      Erik Malund      03/13/06 11:15      
                                          You made a fool of us!        Kai Klaas      03/13/06 18:24      
                                             reply      Suresh R      03/14/06 03:39      
                                                That's no fun!      Kai Klaas      03/14/06 07:06      
                                                   Suresh, I hope you had fun      Erik Malund      03/14/06 07:28      
                                                   reply      Suresh R      03/14/06 10:29      
                                                      yeah 6 days later.      Erik Malund      03/14/06 10:52      
                  Hello Kai,      Suresh R      03/16/06 22:03      
                     Look at here      Kai Klaas      03/17/06 10:56      
                        Thank you very much Kai.      Suresh R      03/18/06 07:40      
                           It just strikes me      Erik Malund      03/18/06 10:20      
                              yes you are right      Suresh R      03/18/06 12:32      
                                 Reed switch problems      Hal Albach      03/18/06 19:31      
                                    Current rating?      Kai Klaas      03/20/06 19:39      
                                       I recall long ago something about a "sti      Erik Malund      03/21/06 06:47      
                                       Reed problem      Hal Albach      03/21/06 07:11      
                                          Glueing together      Kai Klaas      03/21/06 07:35      
                                             Reed problems      Hal Albach      03/21/06 09:14      
                                                reed relayrs      Terry Lingle      03/21/06 14:01      
                           power dissipation calculations?      Suresh R      03/19/06 08:12      
                              bulb voltage drop      Terry Lingle      03/19/06 10:01      
                                 Thanks      Suresh R      03/20/06 02:12      
                                 (.2*bulb resistance      Suresh R      03/24/06 05:36      
                                    The bulb      Terry Lingle      03/24/06 07:06      
                              Constant current during inrush moment      Kai Klaas      03/24/06 07:22      
                                 Thanks a lot Kai      Suresh R      03/24/06 10:12      
         Choke would be huge      Kai Klaas      03/05/06 07:28      

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