I have a bunch of 24v dc fans I want to power from a marine battery at 12v for an rv. each fan draws 110ma I wired them in parallel, so my load is 440ma (I think) Now If I power this directly from the 12v, the fans run slow, so I bought:
**broken link removed**
150W DC-DC Boost Converter 10-32V to 12-35V Step Up Charger Power Module
which by black magic converts the 12v to 24v. but there is a warning on the ebay listing:
Specifications:
Input voltage: DC 10V-32V.
Output voltage: DC12V-35V(adjustable).
Output current: 10A (MAX).
Input current: 16A (MAX) (more than 10A please strengthen heatsink).
Output power: natural cooling 100W (MAX), strengthening cooling 150W (MAX) real power.
Conversion efficiency: 94% (when Input 19V 2.5A Output 16V, Reference).
Output ripple: 2% (MAX).
Working temperature: industrial (- 40 ° c to +85 °c) ( environmental temperature, more than 40 degrees, please reduce power to use, or - enhance cooling).
Full-Load temperature: 45 degrees.
No-load current: 25mA typical.
Voltage regulation: ± 0.5%.
Load regulation: ± 0.5%.
Dynamic response speed: 200uS 5%.
Short circuit protection: No (Please installs the fuse or protection circuit at input parts).
Input Reverse protection: No (please comply with a reverse protection or connect a diode at input parts.)
Size: 65mm x 35mm x 21mm
I believe putting this DC-DC power boost inline will work fine but I have some theory questions if I add more load and
push the input current beyond the 10A suggested limit.
being an amateur, I figured it was like LEDs, all I would have to do iis put a resistor inline (something like a 2-ohm 25watt resistor) and that would "current limit" the input connectors to around 4-6A. The double E guys say that won't work, but can't explain to me why in laymen's terms. While researching this I see some reasonably simple circuit boards that say they will do this, but none seem quite right, and besides, I found it suspicious that I can't find one of these fairly simple "current limiting circuits" pre-built to buy from china for about $2, can somebody explain:
1) what is wrong with my inline resistor Idea and
2) what kind of circuit do I need if the inline resistor doesn't work, or what is wrong with my idea? I don't want to overheat the dc-dc booster.
Here is a typical website that talks about a dc current limiting circuit board:
https://freecircuitdiagram.com/2008/08/27/variable-adjustable-current-limiter-circuit/
or
https://www.radio-electronics.com/i...urrent_limiter/transistor_current_limiter.php