Hello,
I’m trying to make a voltage regulator that can act as a dimmer for a 12v 90watt LED light bar. I made one with the LM317 using a 10k pot, 500 ohm resistor, 0.1uF and 1uF capacitors for a different project that works but limits the voltage too much. Using this circuit I’m able to input 12v but can only output 10V 1.5A as the LM317 is only rated for that much current. Is there another variable transistor I could use that would be capable of outputting 2 or more amps?

Thanks for the help!

 

Use a PWM dimmer.

 

Hello,
I’m trying to make a voltage regulator that can act as a dimmer for a 12v 90watt LED light bar. I made one with the LM317 using a 10k pot, 500 ohm resistor, 0.1uF and 1uF capacitors for a different project that works but limits the voltage too much. Using this circuit I’m able to input 12v but can only output 10V 1.5A as the LM317 is only rated for that much current. Is there another variable transistor I could use that would be capable of outputting 2 or more amps?

Thanks for the help!

No such thing as a variable transistor. There are circuits that can be used with Adjustable Voltage Regulators (like theLM317) to increase the amount of load current available. A more efficient approach would be to use an SMPS (Switch Mode Power Supply).

 

Welcome to AAC!

I made one with the LM317 using a 10k pot, 500 ohm resistor, 0.1uF and 1uF capacitors for a different project that works but limits the voltage too much.

When discussing circuits, you should post schematics instead of trying to describe them in words.

Is there another variable transistor I could use that would be capable of outputting 2 or more amps?

You'll have much better luck dimming if you use a PWM circuit. You can buy something made for a motor.

This one is only good for 2A, but you should be able to find something to handle the current you need.

 

first of all your math does not add up.

if you have LED bar that is rated 12V 90W that means max current is I=P/V = 90W/12V = 7.5A

so you need something that can AT LEAST do 7.5A. that means both the PSU and whatever regulator you use.
i would say go for parts that are 10+ Amp rated.

https://www.amazon.ca/SHNITPWR-Transformer-Regulated-Adapter-Converter/dp/B08BHSNY7F/ref=sr_1_2?crid=2U32EZRY04WOI&keywords=12V+10A+psu&qid=1705367148&sprefix=12v+10a+psu,aps,169&sr=8-2&th=1

https://www.amazon.ca/DC12V-40V-Efficiency-Controller-Variable-Regulator/dp/B0C4ZQWDH5/ref=sr_1_47?crid=2GEB3K4MXJQMX&keywords=pwm+10a&qid=1705366653&sprefix=pwm+10a,aps,76&sr=8-47

and you can always go bigger
https://www.amazon.ca/dp/B09294YN7Z...&s=kitchen&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWw

 

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