Two types of mini light bulbs?

[bdarveaux]

Hi everyone. First time post.

I work at a vinyard/winery. There are tons of Christmas decorations, including about 30 strings of 100 bulb mini light strings. Many of them didn't work and my boss said to just throw them away, but I, knowing a little more then average about mini lights, took them home to fix. Compared to the posts I have read in this forum, I know very little about electronics, but I do know that mini light bulbs have a shunt that can be easily fixed to make the string work again. I also know that mini lights are put in 50 bulb series (2.5 volts/bulb x 50 bulbs is about 120 volts) and these series are then put in parallel for 100, 150, 200, etc. bulb strings.

Here is what I can't figure out. Even though all the strings I am fixing are 100 bulb strings and are all just typical strings (probably all bought from WalMart), there seems to be two different types (that is, they use different bulbs). If, for example, I take a bulb from string A and put it into string B, it will be much dimmer then the other bulbs on the string. If I take a bulb from string B and put it into string A, it burns out in a flash.

So I get online and buy bulk mini light bulbs (because there are a lot of burned out bulbs on these strings). These are 2.5 volt-0.17 amp bulbs. They work great on some strings, but on others they are very dim. Why is this? Are there two different standards when it comes to these bulbs? (That's the great thing about standards - we have so many to choose from .)

I have learned a lot about mini lights this year, but this is the last great mystery.

Thanks,

--Blaise
I am against intellect without discipline. I am against power without constructive purpose. Spock in the episode The Squire of Gothos

[bdarveaux]

Hi everyone,

Well I got the answer to my question by someone else outside of this forum. It turns out that bulbs made from different makers can vary in their resistance. Since, in mini lights, bulbs on the same series circuit divide the voltage amongst them, if you put a high resistance bulb on a string with all other low resistance bulbs, it will appear dim. If you put a low resistance bulb on a string with all other high resistance bulbs, it will burn out in a flash. There is nothing different about the strings themselves that is different, only how the voltage is shared by the bulbs. So on any given string you can replace all the bulbs with either high resistance or low resistance bulbs, (but not mixed) and the bulbs should all light properly.

Does this make sense? Comments?

[cadstarsucks]

Nope.  Different voltage bulbs, yes. 

Typically they do not even bother telling the common clay of the old west, to quote Mel Brooks' Blazing Saddles, what the voltage of the bulb is-only how many bulbs on the string it is meant for.

A bulb meant for a 100 bulb string put in a 35 or ten bulb string would indeed blow quickly.