Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: tdvt on January 28, 2024, 09:13:22 am

Title: LED Strip for Oscilliscope Backlight
Post by: tdvt on January 28, 2024, 09:13:22 am
A friend gave me custody of an older Tektronix scope (TDS210) with a dead fluorescent backlight.

While I have ordered a new fluorescent tube for it, (not yet arrived & no word on shipping) I would like to have a Plan B option, as many of these have been converted to LED surface-mounted strips.

But, I cannot seem to locate a good source for a small, high-density strip. There are many videos/posts about converting these scopes to LED, but the parts links are dead.

The simplest conversion I saw used a voltage divider between the +5V & -5V points on the main board (haven't opened it up yet to verify) to power the strip directly with no additional power supply. The tube/strip light is about 3" long & the screen case could be modded for mounting.

Is anyone aware of a source for a cut-able LED strip that small?
 
Title: Re: LED Strip for Oscilliscope Backlight
Post by: acheld on January 28, 2024, 10:06:30 am
Not sure exactly how small you need, so . . .

I've used lighthouseleds.com (http://lighthouseleds.com) quite a bit -- their stuff is good, and they have technical docs for those of us who don't know LEDs inside and out.

One thing you could do is make a string yourself.   It's not difficult.  You need to figure out voltage drops and current flows to fit your LEDs, and then solder up your string.   If you need (as I did) some direction, check out the "blog" section on the website where they have a bunch of examples.

Also, if I'm not mistaken, Doug has a longstanding interest in LED lighting -- he might have some insight.
Title: Re: LED Strip for Oscilliscope Backlight
Post by: tdvt on January 28, 2024, 12:37:32 pm
Thanks for that link, I wasn't aware of that place. Lots to peruse through, but I am certain there is stuff there to build my own strip.

The videos/posts I looked at so far about converting this scope generally used pre-made series/parallel strips, with the LEDs series connected in groups of 3. You could cut them every 3 LEDs for fitting.

Lighthouse seems to have the individual surface-mount LEDs units, which might be the best bet to getting things sized right as I could space them pretty closely.
Title: Re: LED Strip for Oscilliscope Backlight
Post by: sluckey on January 28, 2024, 01:31:11 pm
I would stick with plan A. Those fluorescent tubes will probably last thirty years. How 'bout you?    :icon_biggrin:
Title: Re: LED Strip for Oscilliscope Backlight
Post by: tdvt on January 28, 2024, 05:07:48 pm
Those fluorescent tubes will probably last thirty years. How 'bout you?    :icon_biggrin:

Yeah...

Technically possible, but I doubt I would remember much about anything...