what is wrong

Hi to you all.

Well, the first problem in the schematic that you made is using a linear voltage regulator (LM7805) and the second problem is using incorrectly the LM7805… like TomGeorge, cbaker391 and Grumpy_Mike were saying, you forget the caps from the input and the output of the regulator to stop the oscillations. (don’t worry, everybody learns from mistakes…)

The linear voltage regulator weren’t design to be used in this way, they are slow, they oscillate and they are extremely inefficient and you will need a decent heat sink for cooling it… you can make them work in this way, but it will be a mess.

In my first clip i just shared an idea and i didn’t talk about triggering the input and powering the project, so in my second version i explain how simple is to use optocoupler to trigger the input and in the third version i showed how you can use a step down buck converter to power everything up (see attachment).

Modern turn signal lights v2.0
Modern turn signal lights v3.0

A good and cheap step down buck converter is MP1584EN, i’ve been using it in countless projects and in never failed for almost two years (yet).

Hope this info helps you and others that are trying to recreate my or other projects.

For other versions check out my channel Think small, build big!

Optocoupler and arduino input.jpg

Hi, @Fjhony
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html .

You can embed those images in your post.

Thanks... Tom... :slight_smile:


I know that i can embed those images in my post, but i don't have them hosted anywhere as they are, only in zip... but i'll put them in the post later on if it helps...


Is the scooter engine a GY6 or GY7? The voltage production on a GY6 is quite noisy.

Also, when I had a GY6, I noticed the rectification was 1/2 wave with minimal filtering.

I'd start with an analysis of the scooter 12V to see what needs to be done to groom the power for use in your project. Your scooter may only produce enough power to barely charge the battery; notice how popular scooter battery chargers are?

What you describe as the "DC jack" is essentially useless! Do not use it - or the "Vin" pin - for any purpose!

I've used mine many times in the last six years on most if not all of my 6 UNOs.
I don't know what the problem is supposed to be but it's always worked for me. The schematic clearly shows that it won't enable the onboard regulator unless the voltage is at least 6V. (see comparator/mosfet switch circuit)

I usually use a 9V battery with a 2.5 mm jack plugged into the barrel jack.
Works for me !

“Works for me !”

PP3 ???

? PP3 ?
What's that ?

Oh , right , the battery !
Yeah, I forgot that.




Please READ THIS POST for future reference.