Home > All images > Alex > High pressure mercury lamps
Return to the thumbnail page FILE 1/7 See next file Skip to end
1972 Philips PowerWhite MBFR 125W --not working properly-- Here you can see a 1972 British made Philips PowerWhite (here is a brand name thats never coming back) reflector Mercury lamp. Sadly this lamp does not work properly and I honestly don't really know why. The lamp starts up normally but then does not warm up. The picture here was made about 20 minutes after ignition. The arctube of the lamp is clear and there seem to be no leaks as it glows normal when excited with a Tesla hid lamp tester. After 20 minutes the lamp draws approximately 40W at a lamp voltage of only 21v. The lamp current is approximately 2A at that point.

1972 Philips PowerWhite MBFR 125W --not working properly--

Here you can see a 1972 British made Philips PowerWhite (here is a brand name thats never coming back) reflector Mercury lamp. Sadly this lamp does not work properly and I honestly don't really know why. The lamp starts up normally but then does not warm up. The picture here was made about 20 minutes after ignition. The arctube of the lamp is clear and there seem to be no leaks as it glows normal when excited with a Tesla hid lamp tester. After 20 minutes the lamp draws approximately 40W at a lamp voltage of only 21v. The lamp current is approximately 2A at that point.

IMG_0410.JPG IMG_0423.JPG IMG_0428.JPG IMG_0451.jpeg IMG_0461.jpeg
File information
Filename:IMG_0410.JPG
Album name:Alex / High pressure mercury lamps
Manufacturer:Philips Lighting ltd.
Type/Model:powerWhite MBFR
Wattage:125W
Date manufactured:09. 1972 Hamilton, great Britain
Filesize:1639 KiB
Date added:10 Apr, 2026
Dimensions:1536 x 2048 pixels
Displayed:96 times
URL:http://80.229.24.59:9232/gallery/displayimage.php?pid=24427
Favourites:Add to Favourites

Comment 1 to 9 of 9
Page: 1

dor123   [10 Apr, 2026 at 10:14 AM]
If it leaks, I would expect to see a glow discharge in the outerbulb, instead of an arc inside the arctube. I can't see from this angle.
Alex   [10 Apr, 2026 at 11:04 AM]
Sorry spelling error, i intended to say no leaks.. (now corrected)
dor123   [10 Apr, 2026 at 11:10 AM]
Can you capture the inside so we can see what happening? (Video would be great)
Beta 5   [10 Apr, 2026 at 11:35 AM]
Strange, I had a Sylvania (only modern Chinese) 50W HSL-BW do this, it lit but just never warmed up Confused
FrontSideBus   [10 Apr, 2026 at 12:27 PM]
Lost outer vacuum I reckon. Maybe try it on a bigger ballast. I can't imagine you would see any discharge in the outer since there is no ignitor in a mercury circuit.
Alex   [10 Apr, 2026 at 12:34 PM]
I though the same and sacrificed a modern 125W Mb lamp by punching a small in it and tried it... It did warm up much more...
FrontSideBus   [10 Apr, 2026 at 12:55 PM]
Could well be a manufacturing defect. I have a Thorn 70w SON-T lamp with no sodium in it!!!
Lightbulbfun   [11 Apr, 2026 at 03:44 AM]
fascinating! I am not sure I have seen a British, Hamilton made 125W MBFR before now! do you have a picture of the etch? as for the defect, I'd say the problem is its either not been dosed with any mercury or not enough mercury to fully build up pressure, (high pressure mercury lamps are not as thermally sensitive like a SON lamp is, so will still run up even if the outer bulb has lost vacuum or completely broken)
Danny   [12 Apr, 2026 at 01:26 PM]
Stunning shame it’s not working correctly

Comment 1 to 9 of 9
Page: 1

Add your comment
Anonymous comments are not allowed here. Log in to post your comment