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View Full Version : not all 2.5v bulbs are the same



PacMang
10-30-2008, 05:18 PM
So i have many different strings from many different stores. I was taking some left over bulbs and building some new solid red strings for my display. When i was done i noticed that some of the bulbs were very dim. Obviously i had some strings that were evergy saver and some that were ultra bright.

all the bulbs are 2.5v so ho do i tell the difference between the ultra bright and energy saver bulbs after they are removed from their strings.

also... what is it in the string that makes one ultra bright and the other energy saver???

Photovor
10-31-2008, 04:36 PM
So i have many different strings from many different stores. I was taking some left over bulbs and building some new solid red strings for my display. When i was done i noticed that some of the bulbs were very dim. Obviously i had some strings that were evergy saver and some that were ultra bright.

all the bulbs are 2.5v so ho do i tell the difference between the ultra bright and energy saver bulbs after they are removed from their strings.

also... what is it in the string that makes one ultra bright and the other energy saver???

Was wondering if you could show a closeup of the 2 kinds of bulbs you have?

PacMang
10-31-2008, 07:47 PM
they are identical to the eye.

rstehle
11-01-2008, 12:04 AM
You might measure the resistance on the bulbs. I would suspect a difference in resistance between the two..........

jpb
11-02-2008, 10:43 PM
I am not sure that measuring resistance will do it because as the measuring current goes through the globe it warms the filament slightly and the resistance varies.

If you know they are all 2.5v create a test rig with a single socket powered at 2.5v. You can then test each globe individually and make a decision based on brightness or connect an ammeter in series and measure the current.

I accidently kicked over my spare globe tray once and had to toss out a heap because I could not work out what specs each one was to put it back in it's correct compartment because I had a mix of voltages as well.

Jon

ErnieHorning
11-02-2008, 11:40 PM
This is a chart that I came up with a couple of years ago. You need an ammeter and a variable DC power supply. It was meant for bulbs that you know nothing about. You start at the lowest voltage and look for a current match within a few milliamps. If you know that it’s a 2.5 volt bulb, then you only need to look at the current.

You can click on the chart to make it bigger.
http://img266.imageshack.us/img266/5912/minilightspowerrating80bq8.th.jpg (http://img266.imageshack.us/my.php?image=minilightspowerrating80bq8.jpg)http://img266.imageshack.us/images/thpix.gif (http://g.imageshack.us/thpix.php)

omzig
11-03-2008, 12:03 AM
Excellent info Ernie! Now I can go through the coffee can full of spare bulbs that I have and maybe actually use some them. Thanks!