Fluke 8050A

[bob91343]

I have one of these but the LCD display is hard to see without an extra light.  Has anyone found a neat way to light the display?

I am considering one of those 1970s lamps that looks like a fuse but need to mount it and connect it.  Maybe an add-on hood mounted to the case and projecting forward.

I don't think backlighting is an option but I am willing to try.

[lowimpedance]

 My 8050's have reasonably good contrast still, certainly do not need any 'side lighting' to help with contrast/reading.
Have you cleaned the elastomer (zebra) strip and PCB contact area, this should eliminate that as a cause of low contrast.

[bob91343]

There is good contrast.  The problem is that there isn't much light where I have the meter and, to make matters worse, it's facing a bit to the side.  A flashlight makes the display very obvious but I'd rather have it lit all the time.

[lowimpedance]

Ah ok...
 If I had to do this I would prefer a LED solution over a filament globe.
Just a thought, perhaps a perspex rod with the surface suitably roughened like bead blasted finish and the LED poked in one end and the other with some reflective surface glued on.

[bob91343]

You give me some interesting ideas.  LED is fine.  The mechanical arrangement is the problem, as well as the electrical connection.  I need to shade the light so it only hits the display.  I am sure the 20 mA or so drain won't overload the power supply.  Surely around here I have some polystyrene rod I could use.  I can use my glue gun to hold it together; that glue seems to come off cleanly when I want it to.

[J-R]

Get a desk lamp from a yard sale instead of molesting a perfectly fine piece of test equipment.

[purpose]

Get a desk lamp from a yard sale instead of molesting a perfectly fine piece of test equipment.

There speaks the logic of the Ancient Flukester.

[BeBuLamar]

You're complaining about the 8050a try Fluke newest 289. The contrast on the 289 is very poor.

[bob91343]

I do have desk lamps.  But this meter is a pain no matter what.  I don't consider adding a lamp to be molesting, since it will be attached with removable glue.  Just pop it off and the meter is once again pristine,  It's just the mechanical details I find challenging.

For instance, I could drill a couple of blind holes in the ends of a polystyrene rod, insert LEDs, paint most of the rod to eliminate spurious light, and glue the assembly to the lower edge of the display.  Then run leads down and under and sneak them into the case where they could get power.

Seems like a lot of trouble.  And ugly.

[AVGresponding]

Have they changed the LCD on the 289? My early one has no problems with contrast   

I think 20mA would be way more than you'd need for backlighting an 8050A, if you cut of one section of some 12V LED tape for example, and put an extra resistor in series now it happens that I can't remember the power rails on the 8050A...   

Ok had a quick look at the schematic. You could probably power it off the -5V rail. If you choose a resistor to limit the current to 1mA or so, it shouldn't cause a problem, and I'd bet it would be bright enough to edge-light the display

[J-R]

Get a desk lamp from a yard sale instead of molesting a perfectly fine piece of test equipment.

There speaks the logic of the Ancient Flukester.

I remember using the Fluke 8050A and similar back when I was working on my EE degree.  So I picked up a few this year out of nostalgia. Got a lot of 3 that were not working and was able to get two up and running.  The third has a bad LCD where the liquid has bled all over.  LED conversion project at some point!

[J-R]

You're complaining about the 8050a try Fluke newest 289. The contrast on the 289 is very poor.

Viewing angle and lighting direction impact the clarity of the 287/289.  Certain arrangements are terrible.

I have a 287 and have adjusted the contrast and the placement to maximize the visibility.  I'm happy with it.

But I'm moving towards bench meters with VFDs or similar for most tasks.  My 287 is my most accurate portable DMM at the moment though.

[bob91343]

One of my favorite functions is the conductance, which can measure very high resistance.  I like the REF button as well.  I wish it autoranged but it doesn't.

Someone said something about edge lighting the display.  I don't see any way to do that.  The display appears closed to extraneous light.