Products > Test Equipment
Replacing OLED screen on an Agilent U1253A Multimeter
AVGresponding:
Set your mind at ease; I have the display brightness set to low. At £70 + shipping, I want it to last as long as possible!
gamalot:
--- Quote from: AVGresponding on December 11, 2022, 05:12:14 pm ---Set your mind at ease; I have the display brightness set to low. At £70 + shipping, I want it to last as long as possible!
--- End quote ---
Thanks, your reply saved my day.
I've always wanted higher power conversion efficiencies in battery-operated devices, but the chip shortage is indeed causing a lot of trouble.
--Oz--:
I will try and measure the current my meter drinks tomorrow and report back.
I would think adding three simple logic gate ic's would drink less than a mpu, but lots of variables
The stock nimh 9v energizer battery I got with my meter was 225mah. We know this 225mah is valid from energizer (they dont lie).
The li-ion 9v I use is rated at 600mah but tested to 520mah (its used and may have lost some capacity), but thats 2x the stock battery life.
With some good li-ion 14500 (AA size), they are 900mah (tested) and would give 4x the stock battery, that is low hanging fruit for little work.
If we could find some Li-ion pouch cells to fill the battery compartment (roughly 53mm wide X 17mm thick X 26mm high) more efficiently than round 14500 cells, should be at least 1200mah, or 5x the stock battery run time.
Maybe even use a wireless charger to charge the 2S Li-Ion pack.
--Oz--:
I found a stock meter (no OLED display replacement).
This U1253B battery icon has these reaction.
Keysight Stock. Agilent Modded.
9.40v full battery bars, 8.1v full battery bars,
9.3 to 9.0v 3 bars,. 8.0 to 7.7v 3 bars,
8.9 to 8.3v 2 bars,. 7.6 to 7.2v 2 bars,
8.2 to 7.3v 1 bar,. 6.65v shows 1 battery bar then turn off.
7.26v "X" in battery,
Works ok down till 5.7v,
At 5.6v the numbers jump around,
Current consumption (mA):
Keysight Stock. Agilent Modded
Vin Lo Med Hi. Lo. Med. Hi
10v. 23. 30. 34. 26. 32. 36
9.4v. 24. 31. 35. 27. 33. 37
8.4v. 25. 32. 37. 28. 35. 39
7.4v. 26. 34. 39 30. 37. 41
6.0v 29. 40. 44. Turned off at 6.65v
Clearly the two meters have different firmware and possibly hardware changes.
For the fun of it I powered a populated adapter board with 3.3v, current was 0.81mA.
Edited: 12-13-2022
--Oz--:
Will try and test my modded meter tomorrow.
The three IC's have very low idle current, total for the three is around 5uA.
All three work down to 3v, so lowering the 3.3v supply would work with the adapter board.
Two ideas.
1. Is there a "dark mode" for the OLED display? Could save some power there.
2. Is there a way to pwm the OLED display brightness (like you could could do with lcd)? Yea, long shot on that one, haha.
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