IRW Posted February 27, 2008 Share Posted February 27, 2008 Until some one turns up the brightness... I don't think the 500w versions are 'cheap' :) This one doesn't appear to be too OTT! EDIT: And this one from good old B&Q is even cheaper! Link to comment Share on other sites More sharing options...
DaveP Posted February 27, 2008 Share Posted February 27, 2008 from good old B&Q is even cheaper! Yes.. that will be the best option :) Link to comment Share on other sites More sharing options...
paulears Posted February 27, 2008 Share Posted February 27, 2008 fairly simple job to mod a dimmer switch so t can't go all the way up - and the OP isn't too worried about cost, is he? Link to comment Share on other sites More sharing options...
GasMan Posted February 27, 2008 Share Posted February 27, 2008 Use a dimmer to get the right effect, then take it apart and replace the pot with fixed resistors! (don't move the setting till you've measured it) SimpleCheapEffective Result !!! Best of luck John Link to comment Share on other sites More sharing options...
KevinE Posted February 27, 2008 Share Posted February 27, 2008 I think the OP mentioned NOT using a dimmer. Link to comment Share on other sites More sharing options...
Wuddy Posted February 27, 2008 Share Posted February 27, 2008 Did I miss something? Hi All.>SNIP<The old lamp is still working and I would like to make an illuminated ornament for (perhaps) domestic use. I therefore only want the filament to glow. Can anyone think of a simple way of achieving this that avoids using a dimmer? How about a standard wall-mounted dimmer light switch? An easy and cheap solution if it can be incorporated into the design!fairly simple job to mod a dimmer switch so t can't go all the way up - and the OP isn't too worried about cost, is he?Use a dimmer to get the right effect, then take it apart and replace the pot with fixed resistors! (don't move the setting till you've measured it) Must learn to type faster Link to comment Share on other sites More sharing options...
DaveP Posted February 28, 2008 Share Posted February 28, 2008 I think the OP mentioned NOT using a dimmer. Thats true... but As using a dimmer is by far the best method, I for one chose to over look that bit :) Link to comment Share on other sites More sharing options...
gnomatron Posted February 28, 2008 Share Posted February 28, 2008 The OP might have been avoiding a "proper" dimmer, the domestic one might be ok. Anyway, you could use glue and the existing pot if it came to it. Link to comment Share on other sites More sharing options...
IRW Posted February 28, 2008 Share Posted February 28, 2008 I think the OP mentioned NOT using a dimmer. Thats true... but As using a dimmer is by far the best method, I for one chose to over look that bit I took it that the OP was talking about 'proper' dimmers such as LD90's or Betapacks, or any other type of theatrical dimmer. :) Hopefully he will be along at some point and clarify this. :) Edit: Beaten to it! Link to comment Share on other sites More sharing options...
Bryson Posted February 28, 2008 Share Posted February 28, 2008 I certainly hope that's the case, otherwise it would be like saying: "I need to switch something on and off, but would like to avoid using a switch for no particular reason....." Link to comment Share on other sites More sharing options...
DaveBeattie Posted February 28, 2008 Share Posted February 28, 2008 What about using the power supply from an old laptop? Many of these are single DC voltage and capable of pushing quite a current. <... looks at handily close HP variant ...> 18.5v at 3.5A. Do you think that this voltage would be enough to cause a good glow and do you think that the current rating would be high enough to cope with the load? Hope this helps Dave Link to comment Share on other sites More sharing options...
RoyS Posted February 28, 2008 Author Share Posted February 28, 2008 Wow! I’m amazed at all your responses and would like to thank all who have posted thus far. Where do In start?... This lunch time I have been messing around with a bench power supply and have got the lamp to glow very nicely with 35v drawing just under an amp. The capacitor route suggested by David Buckley and others sounds good to me. David would you mind recalculating for me? As far as the dimmer point is concerned…. I don’t want to use a domestic one because most are rated for 300W loads. 500W ones are available I know but this would be using it to it’s maximum rating and in my experience it’s working life would be short.. Domestic dimmers also have a propensity to buzz, if not at first, then probably after some use. 500W and above domestic dimmers are not that cheap either.. As far as a professional dimmer is concerned, I could try persuading the good lady of the house the industrial chic aesthetic of a 48-way flightcased dimmer rack in the lounge, possibly under the telly would look cool, but it’ll take some work and all the Shiraz in California…. Hang on….That trick worked for the black stockings….Em..Maybe I could give it another try… :D Thanks and best wishes to all. R0Y Link to comment Share on other sites More sharing options...
dbuckley Posted February 28, 2008 Share Posted February 28, 2008 Well, first ohms law, r=E/I, so R=35/<just less than one> so lets say 35R. 240V-35V=205V, so the other resistor of the potential divider is 205R. From the web site, 205R is 15.5273uF, so from the vendors page choose 16uF. Link to comment Share on other sites More sharing options...
themadhippy Posted February 28, 2008 Share Posted February 28, 2008 That trick worked for the black stockingsDo tell more Link to comment Share on other sites More sharing options...
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