Re: Has anyone replaced the Graticule lights with LEDs?


Eric
 

Led moding a 7000 Series Scope after crawling in to my head from a year ago.

The LEDs used were Adafruit / 754 Super bright White Leds. Important notes on these Vforward for the diode being white is 2.5Vdc this is important later. Led Size is 5mm Clear

Dropping resister – None

Power supply open circuit voltage – 8.1 Vdc at full illumination

LED wiring parallel like the old light bulbs

The lamp illumination is current limited by the scope its self. When the LEDs are connected and the illumination on FULL the voltage across the connector in the scope is only 3.2 Vdc this means that the Leds are only drawing about 40mA each this was verified on a 577. This is why the leds don’t burn up with no current limiting resister. This is running the leds at about 2X design spec but after running one like this off a lab power supply for a few hours it is barely warm to the touch and has not moved from a round 0.031 mA current draw Amp meter in the power supply so not the best thing in the word for measurement.

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Harvey White
Sent: Sunday, May 23, 2021 6:31 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Has anyone replaced the Graticule lights with LEDs?

LEDs can be gotten in different dispersions, some, for instance, I think at 130 degrees. If you have a 3D printer, you might be able to make a light shroud depending on your needs. If you can do PC boards, then I could recommend a 3 color LED. How to profitably control it is another matter. Otherwise, pick a color depending on what you want.

It might get close to an incandescent lamp.

Harvey


On 5/23/2021 5:15 PM, DaveH52 wrote:
In a few days, I'll be disassembling my 2465 again to install a replacement module for U800. Since it will be totally disassembled, I'm seriously considering replacing the graticule lamps with red LEDs. I plan on 'frosting' the tops so the light will be more diffused. It worked well for the meter on my Kenwood TS-440, except I used white LEDs for that.





Join TekScopes@groups.io to automatically receive all group messages.