Light bulbs for lamp limiters.

[Station X]

RS Components stock 100W Rough Service Bulbs:-

http://uk.rs-online.com/web/search/s...duct&R=0604624

Maplin have normal 100W bulbs, but they are out of stock at present for online ordering. Some stores have them in stock though:-

http://www.maplin.co.uk/Module.aspx?...rderCode=GB16S

Other suppliers are available.

[Tim]

I prefer clear bulbs for the LL, it makes a really dim filament easier to see. You don't see them everywhere though. i stocked up a few years ago

[Neil Purling]

Would someone like to message me on the difference between the ordinary 100W bulb & the Rough Service alternative. More supports for the filament perhaps?

Please reply by PM only as the question is definitely OT.

[ppppenguin]

The last time I looked both Robert Dyas and Poundland had ordinary 100W bulbs. The 70W(?) halogen in GLS gives about the same light as a 100W GLS bulb but is obviously less well suited to larger radios and TVs. 2 in parallel is the answer.

There's no mystery about rough service bulbs. They are underrun and have more filament supports.

Within reason, for a given wattage and technology a lower voltage bulb will be tougher and give more light. This is due to a thicker filament. 230V 100W GLS gives about 1300lm, 110V 100W GLS about 1700lm.

[paulsherwin]

Market stalls also still sell bog standard 100W pearl bulbs, though clear ones are scarcer. I find the pearl ones to be OK in a limiter - the bulb will glow noticeably when passing any significant current, and you soon learn what they look like with various loads. Possibly this is less true if you have a very brightly lit workshop though.

[BGmidsUK]

Maplin also sell 105W GLS halogen bulbs (150W equivalent), I have a couple of them.
I wonder if those giant heat-and-light bulbs are still available? Haven't seen any on the shelves recently.


Brian

[XTC]

You can still get 40W incandescents in Tesco. You could just parallel two or three.

I see 60W and 100W incandescents at car boot sales, the local ironmonger and pound shops, 150W are becoming a rarity, although I saw some 200W in a local hardware shop a month or two back. I think you can get them on ebay and there are some specialist ones such as rough service and artist's natural daylight lamps around. There may be others around such as the bulbs used for coal effect fires.

Definitely time to keep your eyes open and stock up, if you haven't already done so.

Pete.

[qualityten]

Originally Posted by ppppenguin

There's no mystery about rough service bulbs. They are underrun and have more filament supports.

Within reason, for a given wattage and technology a lower voltage bulb will be tougher and give more light. This is due to a thicker filament. 230V 100W GLS gives about 1300lm, 110V 100W GLS about 1700lm.

Recently a cold 'rough service' 100W bulb slipped out of my hand and dropped onto the carpet. I was impressed by the thorough collapse of the entire glass innards.

[Phil G4SPZ]

My lamp limiter has two bulbs, switchable between 60 watt and 100 watt or both in series. I also find clear bulbs easier to 'read', although I usually run up equipment from an isolating transformer via a variac and through an old Avometer, set to the 1.2 amp AC current range.

I have a number of Philips 250 watt Photoflood bulbs. These have a standard sized pearl envelope and a BC cap. Their design life on 230 volt mains is about one hour!

[arjoll]

Are 'normal' incandescent bulbs really getting that scarce there? Here you can get them at any supermarket or hardware store!

[Station X]

Not just scarce, but in some cases banned from sale environmental reasons. It's difficult to get lamps over 60W. Rough Service lamps are available, but not widely available.

http://www.lightbulbs-direct.com/art...ight-bulb-ban/

[Coastwatch]

Once bulbs have gone could cheap soldering irons be used. If suitably boxed (draft proof) perhaps a simple circuit with a thermistor or thermocouple and meter could be implemented to give a visual reading to replace the glow of the bulb, or am I way of track

Cheers n Beers,

David......

[Phil G4SPZ]

The lamp limiter not only limits current drawn to a safe maximum level, but also gives an immediate indication that something is wrong or not. A soldering iron would do the former, but not the latter.

As has been suggested, simply paralleling multiple incandescent lamps of lower wattage would work - two 60 watt lamps would be more-or-less as good as a single 100 watt lamp. Just a nuisance having to wire two lampholders in parallel. Small 'golf ball' or candle-shaped 40 and 60 watt clear bulbs are likely to remain available for some time to come.

[paulsherwin]

Originally Posted by arjoll

Are 'normal' incandescent bulbs really getting that scarce there? Here you can get them at any supermarket or hardware store!

Our friends in Brussels are behind the progressive withdrawal of consumer grade incandescent lighting, primarily for energy efficiency reasons. This has been quite controversial and very unpopular in some quarters. Commercial rough service incandescents continue to be available but are relatively expensive.

This subject is OT for this thread though.

[davegsm82]

You can get a 5 pack of mixed 40w and 60W incandescents (clear) from our local poundland.

Dave.

[Paul Stenning]

In practice unless roughly handled the bulb in a lamp limiter should last a long time because it is only used for short periods of time and generally at low levels (unless the set in question has a dead short on the input). So there is probably no need to stock up with loads of bulbs.

[Hybrid tellies]

I have just bought some 100w pearl bulbs from the local maplins. They were in the special offer sales area.

[mrmagnetophon]

geez here i bought a box of 10 100 watt heavy duty bulbs for 2 dollars at the hardware store, can't you just run a couple of those in series and parallel to get what you need? i understand that you need higher voltage but these are good for 130 volt. so 130x 2 should be enough.

[BGmidsUK]

100W 240V bulbs are still readily available in the local shops here (in both ES and BC) despite having disappeared from the supermarkets some time ago. My local Aladdin's cave (hardware) has 150 and 200 watt bulbs in stock. I use them in parallel when more juice is required.

I also have a box of 60W 110V bulbs, didn't notice the rating until I'd got them home. Good job I didn't screw one straight in as it would have exploded! Tested on a transformer to confirm voltage. These could be used in series.


Brian

[Coastwatch]

Originally Posted by davegsm82

You can get a 5 pack of mixed 40w and 60W incandescents (clear) from our local poundland.

Dave.

And poundstretcher as well.

Cheers n Beers,

David.......