Voltage regulator for bike light (12V to 7.2V)

[storab]

I‘m planning to connect my old LED lights to the 12V output on my Turbo Levo.
The lights (Magicshine/Ultrafire) are built for 7.2V battery power and I am planning to find a voltage regulator that can be placed inside the frame.

Anyone that have made this kind of solution already or know of any products I should look at?

 

[indypup]

You ever find a solution? I'm wanting to do the same thing...

 

[indypup]

I think we need a DC-DC converter.

 

[Slapbassmunky]

Those magicshine lights will want 8.4v for maximum output, equivalent to a fully charged 2S lithium pack. Current draw will depend on what model you have. DC-DC Buck regulators are available on a well known auction website.

 

[indypup]

Those magicshine lights will want 8.4v for maximum output, equivalent to a fully charged 2S lithium pack. Current draw will depend on what model you have. DC-DC Buck regulators are available on a well known auction website.

I wish I remembered everything we covered in my electrical classes at college way back when...lol Good thing we have google and youtube and of course this forum and ones like it...lol

 

[Slapbassmunky]

Google a BEC - Battery Eliminator Circuit - depends on how what amps you want to put through it?

Example

Matek Micro BEC 6-30V 5V/9V Adjustable (3pcs)

Matek Micro BEC 6-30V 5V/9V Adjustable (3pcs)

www.hobbyrc.co.uk

Those BEC's aren't up to the job, they're designed for pulse loading. Most XML style lights pull upwards of 2.5A continuous when the light is at 100%

 

[Slapbassmunky]

Try an auction site, search for XL4005, pick the most basic one with an inductor that lies flat across the board. When you receive it glue the inductor down with a big blob of silicone sealant.

They're rated up to 5A which is overkill. Realistically these cheap buck converters are good for 50-70% of their rated output before they cook themselves. Especially when sealed in heat shrink and hidden in a frame. Potted I/P rated industrial quality solutions become very expensive very quickly.

You would be better off replacing the light or the driver PCB for one that accepts 12V if at all possible.

 

[BeBiker]

I‘m planning to connect my old LED lights to the 12V output on my Turbo Levo.
The lights (Magicshine/Ultrafire) are built for 7.2V battery power and I am planning to find a voltage regulator that can be placed inside the frame.

Anyone that have made this kind of solution already or know of any products I should look at?

I have a similar Aliexpress battery powered light, and tried it on a regulated power supply.
Lower than 5V the light goes out

The current goes up together with the voltage and brightness till +-8V
Up to +-16V the current and the brightness stayed the same.