SteveR
Member
Offline
View
Posts
View Gallery
|
Hi. I have a mid 20th c Osram bulb of a squirrel cage filament design. I would like to know if its still in working order but don't have a bayonet fitting to test it. It's a 60w, 240v bulb. I put a multimeter across the base and got a reading of 75ohms resistance. The filaments all look to be intact. And the glass is still clear. Does this mean that it may still be viable? Is that resistance reading about right for this bulb? (I only have a really basic level of electrical knowledge). Thanks, Steve.
|
|
|
Logged
|
|
sox35
Guest
|
|
Bulbman256
Member
Offline
Gender:
View
Posts
View Gallery
Mad Max
|
|
|
Logged
|
Collecting light bulbs since 2012, a madman since birth.
|
sox35
Guest
|
|
|
Logged
|
|
SteveR
Member
Offline
View
Posts
View Gallery
|
Thanks guys, just knowing that it may still be viable is good news. I probably won't light it up as I don't need to. I can put a modern 60w bulb into the lantern that the older bulb came in and get it working. Am I right in thinking these bulbs have approx. 1000 hours service life? If so, if it's done 999, I don't want to be the guy who blows it! Thanks, Steve.
|
|
|
Logged
|
|
sox35
Guest
|
Don't worry, it's not going to blow the instant it hits 1000 hours Put a picture of it up on the gallery, always interesting to see what other people have. By the way, welcome to the madhouse that is LG from the frozen North East of Scotland
|
|
|
Logged
|
|
Bulbman256
Member
Offline
Gender:
View
Posts
View Gallery
Mad Max
|
|
|
Logged
|
Collecting light bulbs since 2012, a madman since birth.
|
SteveR
Member
Offline
View
Posts
View Gallery
|
Thanks Sox....Scotland cold, Lancashire very wet! I guess I'm just a bit nervous about putting current through something that hasn't been used for 50 plus years.... I posted a picture of the bulb on a recent post (Osram Dating) a couple of days ago. Thanks, Steve.
|
|
|
Logged
|
|
sox35
Guest
|
It's not all that bad at the moment, if anything it's a touch on the humid side, which is one of the things I hate; I don't mind heat but humidity is a killer What I do with old lamps is run them up very slowly through a Variac, just so I can see if the filament is intact and the outer bulb has not let air in. Just seen your post, would still suggest you post a picture on the gallery though, that's where people expect to see them and it'll most likely get more views and comments. Nice lamp, by the way
|
|
|
Logged
|
|
funkybulb
Member
Offline
Gender:
View
Posts
View Gallery
|
Nice to see that u have nice incandescent lamps I think most of those lamps are under a Vacumme Your not a quite out of the woods yet.
First step what u done is correct using a meter and See if u got a reading that it not open.
Now second step this where it gets important Is to invest in a Variac that way u can ramp up The voltage slowly till the fillament to start to glow red Justjust a bit more. Now this it time u let the lamp warm up a while and if there any air inside the lamp u will know u have a problem when have a hot spot and glass heats unevenly. If iyou dont have that problem. Then u can enjoy it and bring the voltage slowly up whike u watching for antthing abnormal. My best advice is not run them full power about 1/2 to 3/4 voltage to the lamp.
|
|
|
Logged
|
No LED gadgets, spins too slowly. Gotta love preheat and MV. let the lights keep my meter spinning.
|
SteveR
Member
Offline
View
Posts
View Gallery
|
Great advice thanks. It seems that yourself and Sox agree about using the Variac and it makes sense. I'll have to see what I can do....
|
|
|
Logged
|
|
sox35
Guest
|
If you want to avoid buying from China (especially when they fit those awful and totally non-compliant multi-plug sockets on them) then they can be a bit on the pricey side, but they are well worth the investment.
|
|
|
Logged
|
|
joseph_125
Member
Offline
Gender:
View
Posts
View Gallery
|
If you were in a 120v area I would go with a Powerstat/Superior Electric or Staco branded one. They're a bit expensive over the imported models but as far as I know both brands still make their variacs in the US.
Personally I would find a vintage unit. I have a vintage 2200VA Powerstat unit and it works great to run up my 1000w incandescent lamp. The top vintage brands would be the aforementioned two as well as General Radio/Variac.
|
|
|
Logged
|
|