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EL Panel Dimming - please help

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Junior Member level 3
Feb 7, 2002
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I am putting together an EL panel for an instrument panel backlight. It has a 12 VDC input and a 170 VAC EL panel drive.

I have been unable to find any info on how to add a dimming feature. I am assuming it is simply a pot inline on the output. But what resistance? Is that really where it should go? Etc.

Any help would be appreciated!

by what i know the light intensity is controlled via. the freq and the voltage.
higher voltage and higher freq more light
but dimming would only regulating one of them.
Try mesuring the current flowing thru the backlight and calc a resistor via ohm's law

As I know you should NOT connect pot between EL lamp and inverter. Connect it for control DC level on the inverter's input. Also inverters allow digital dimming by PWM. You can read more information on the inverter manufacturers site. For example

Best Regards

You should definately not connect a POT to the output of the inverter.

Do you need smooth control or just a 2 step (hi/low) type of control ?

For smooth dimming, try this .

use a LM317 type of variable voltage regulator. use a pot to adjust the output voltage and feed this voltage as supply to the inverter.

for 2 step dimming, use the same circuit - replace the pot with a switch and 2 resistors to set 2 different voltage levels.


Thanks for the assistance. Now that I am enlightened, I am off to try to make the panel dim!

A few more points to keep in mind when working
with EL inverters. Never, ever, apply power to the
input without the output being connected to the EL
panel. Always remove power from the input side,
never from the output side (such as with a switch).
Watch the output. Yes, it is very low current, but
it still will sting you.

And like the others have said, the easiest way
to control the brightness is by controlling the
voltage going into the input of the inverter.



What kind EL power you got? Do you use driver chip? If so use chip datasheets to find resistor/capasitor that controls boost voltage/EL driving frequency. That's the place where you should add control. I added NPC driver chip LDR to control brightness

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