Author Topic: Vishay OLED brightness  (Read 150 times)

ym2612

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Vishay OLED brightness
« on: October 29, 2017, 10:53:31 PM »
Hi all,

I'm building a PreenFM2 and I chose a Vishay OLED from Mouser for its white text display. https://www.mouser.com/search/ProductDetail.aspx?r=78-020N004AWPP5N0000

It works, and text is visible, but it's quite dim compared to photos I've seen of the yellow OLED. I soldered a jumper for the OLED resistor and verified that 5V is being delivered to the display (which is what the supply voltage is rated at). Is there a modification I can make to increase the brightness of the display?

FWIW, so far I hear no extra noise.

ym2612

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Re: Vishay OLED brightness
« Reply #1 on: October 30, 2017, 07:24:33 AM »
Also, I should mention that the Vishay display is slightly too thick to fit behind the acrylic screen protector included with the metal case.

Xavier

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Re: Vishay OLED brightness
« Reply #2 on: October 30, 2017, 09:07:12 AM »

Thanks for the feedback about this display.
A jumper for the OLED resistor was the way to go if your display is not bright enough.
I don't think there is other thing you can do.

Do you have a picture of it ? that reflects the brightness you see.

For the noise, you have to put a spectrum analyser (http://www.voxengo.com/product/span/) to be sure it does not add any noise at any frequency. Most of us don't hear the 13.5Khz peak of the yellow display.
Would be great to view what is the spectrum of you audio output with the preenfm2 switched on.

Xavier


ym2612

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Re: Vishay OLED brightness
« Reply #3 on: November 13, 2017, 07:36:17 AM »
Sorry for the delay on these images. I took screenshots in a spectral analyzer for iPad.

Vishay display (clickable image):


Yellow OLED (no shield):


Yellow OLED (homebrew aluminum foil shield):


As you can see, the noise spike is still very present and audible even with the shield I made, so hopefully I can make another display work or fabricate a better shield.

ym2612

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Re: Vishay OLED brightness
« Reply #4 on: November 13, 2017, 07:40:29 AM »
Here are some photos of the Vishay display plugged in:


Xavier

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Re: Vishay OLED brightness
« Reply #5 on: November 13, 2017, 09:34:06 AM »

Thanks a lot for the screenshots.  :)
That's very usefull and interesting.

All people who were annoyed by the high frequency peak reported it's not audible anymore after the shield + OLED resistor modification.
If you haven't done it before, look at the spectrum while trying to find the best place for your shield. 5mm can make a difference.
Also, verify what you hear is not directly the display (put the preenfm2 far away from you) and not a peak in the audio. (That happened to someone);.

I've just ordered a white and a green OLED display (Raystar). I'll report what result i got from them.

Xavier

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Re: Vishay OLED brightness
« Reply #6 on: November 18, 2017, 05:07:22 PM »
The white Raystar i just received is also much darker than the other colors.
Its brightness is very sensitive to voltage. You need a strong 5V.
I quite like anyway it and it's very quiet :)

The green one is very nice but same nois as the yellow one.

ym2612

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Re: Vishay OLED brightness
« Reply #7 on: November 19, 2017, 04:02:09 PM »
I switched my yellow OLED back to the white Vishay. It's dimmer, but I prefer the lack of noise.   :) I'll just avoid pointing a work lamp directly at it.