LCD backlight from unregulated 9V?

[ris8_allo_zen0]

Hello,

maybe I've not searched very well on the forum, so I couldn't find an answer to my question: if one has an optimized PSU, what about powering the LCD backlight from the unregulated 9V, between the rectifier and the 7809?

I don't think the backlight requires stabilized voltage, and this would reduce some heat from the stabilizers...

Tell me!

Best regards,

Enrico

[lylehaze]

This depends on the type of backlight.

If it is LEDs, you can calculate the correct resistance using one of the LED resistor calculators on the web.

Make sure you figure using the highest voltage that you ever expect to handle (fresh new battery).

The backlight might be a bit dimmer as the battery voltage drops, but I doubt it will be enough to be a problem.

Have Fun,

LyleHaze