Bench magnifier led lamp conversion
 

Hi Peeps.. Over the years as the light dims, or is that eyesight getting worse, I found the need to use an illuminated Bench magnifier even more.
The original one had the usual circular fluorescent lamp, which was more of a safety issue , especially with the solder de sucker attacking the tube on occasion. I have posted previously my modification to LED strip illumination.
This was ok, but due to early led types, I found Leds failing quite regularly, until I dropped the DC voltage to 11V from 12V.
I found on ebay a new source of led strip. More White, than previous and more leds per inch. A reel cost £4.49 per 5 metres. I fitted the new leds and I am amazed at the improvement. See photo's. For a couple of hours work, removal of the high voltage source, it is a very worth while mod, . One point of note.. dont trust the self adhesive backing. Bostic or other is most necessary.

Re: Bench magnifier led lamp conversion
 

That's interesting. I've got a similar lamp, and yes the tube is always at risk.

I've used that type of LED strip before; I have a length under the shelf that is above my workbench. I've also used it inside my grit-blasting cabinet, where it is stuck on the window so that 100% of the light is directed at the work piece. The cabinet originally had a fluorescent tube on the back wall, so has much light shone in your eyes as on the work piece :(.

B

Re: Bench magnifier led lamp conversion
 

That looks good, I must do mine too.

Can you provide a link to the source, or a note of the manufacturer and type number?

Re: Bench magnifier led lamp conversion
 

I had an old long reach round tube CFL magnifier. Then bought a similar LED unit. The LED arm only had two bars on each arm and was prone to swaying. I grafted the new head onto the old arm that had three bars on the main arm. This is very stable now. I think this may have been the reason I got it so cheap, because it was so unstable.

John.

Re: Bench magnifier led lamp conversion
 

I did a similar conversion but used a circular led panel made for the job.

https://www.ebay.co.uk/itm/234638808541

Just an example, other suppliers are available.

Peter

Re: Bench magnifier led lamp conversion
 

That is one solution I was not aware of. There seems to be a LED board for just about any fittings. I have used a few 2D LED boards.
One thing to consider when converting a lamp like mine in #4 is that the head will be lighter and want to lift all the time, especially if there was a heavy ballast attached.

John.

Re: Bench magnifier led lamp conversion
 

Grrrrrr.. I wrote a rather longish reply, only for the Tinternet connection or modem to fail, thus I lost it.. so I am not repeating it. However the Wall wart mod may be of interest. As I say I reduced my voltage to 11V to help with long levity. After opening the case, the set resistors are on the "cold" side of the PSU, usually two 1% resistors. the lower, as in "to ground" resistor needs shunting. I used my resistance box to get "near enough". But PLEASE ensure safety and case integrity afterwards.
Sorry Dave ebay link. or code (353811725474), but that supplier is now defunct. But others are on the site

Re: Bench magnifier led lamp conversion
 

Hi.
I found one of these being dumped in the skip and ran over and rescued it. The cord from the transformer/ ballast unit at the base, & the lamp was open circuit, presumably the reason for its disposal. Didn’t take long to fix, but hubris struck as the tube went after about a week. I did manage to find a tube some years ago, but I shall bear your tip in mind Wendy for the day-which may already be here- when tubes are no longer available.

Don’t LED’s need a constant current?

Re: Bench magnifier led lamp conversion
 

I know exactly how you feel, You just don't feel like doing it all again. Happened to me on more than one occasion.

Sorry for OT please delete if necessary.

John.

Re: Bench magnifier led lamp conversion
 

That is my understanding. The LED board in the above link shows 85v AC -265v with output 40v - 80v DC @ 220ma. There may be a settable current chip in the control box.

John.

Re: Bench magnifier led lamp conversion
 

It's worth mentioning that there are direct LED replacements readily available for these circular lights. Just search LED T9.

Steve.

Re: Bench magnifier led lamp conversion
 

That was worth finding out. However I see they come with a replacement starter that my lamp doesn't have!

Re: Bench magnifier led lamp conversion
 

Then you should wire out the ballast and the replacement LED tube will work nicely.


An afterthought: the LED replacements are available made from polycarbonate rather than glass although you can get glass ones too. A polycarbonate one will stand up to the odd knock with a solder sucker etc. so I would go for that type every time.

Steve.

Re: Bench magnifier led lamp conversion
 

TBH, I think the problem will be the lack of ability to easily wire out the starter which isn't there. As well as the on / off switch, there is a momentary switch which I think is in place of the starter. Most times just switching on, it lights up, but sometimes I have to operate the momentary rocker, I think mostly when it's cold in there. Of course I could short out the start switch, but am I missing something other than the possible risk that after conversion someone could put a conventional tube in? But then again I think I'd remember! Oh and yes, I've smashed one tube, and had several near misses on the second with a spring loaded solder sucker.

Re: Bench magnifier led lamp conversion
 

I cannot help you any further I'm afraid but I will make the following comment for anyone else who might find it useful.

LED replacement tubes require no starter and you connect them to the mains via a switch in the same way that you would wire a normal incandescent bulb. None of the 'guts' associated with a conventional fluorescent tube is required. I cannot think of a fitting that could not easily be modified.

In every LED replacement I have ever had there is a sticker to fit under the tube to make it clear that the fitting has been modified for LED tubes only.

Steve.

Re: Bench magnifier led lamp conversion
 

Yes. The replacement tubes I've used come with a replacement starter which is a wire link.

In most fluorescents with a ballast (as opposed to electronic control gear) the starter heats up and goes open circuit to 'start' the tube (as I understand it).

My lamp has no 'starter' as such. It does have a start switch, which is a momentary rocker. I don't have to use it all the time. Only when the lamp is cooler. My assumption is that this is O/C at rest, and so would probably need to be shorted out permanently to wok with an LED tube.