Comments: LED Light Bar Hookup
Looking for answers to technical questions?
We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.
Hi, I have a question about dimming the led. Does it have to be using pwm or can a pot do the job? If both works what is the advantage of pwm over simple pot?
- PWM is more energy efficient than a pot in series with a LED. Power is lost in the pot to heat.
- There is a dead spot when turning the pot to overcome the forward voltage of the LED.
- PWM gives more precise control of brightness given the voltage to current relationship of LEDs.
If you want a pot in your design, as the tutorial suggests you can connect the pot to the ADC input of a micro-controller and adjust brightness through software or have it in a 555 circuit that generates a PWM signal.
If you've found an issue with this tutorial content, please send us your feedback!
I am in a wheelchair and rely upon digital LED lights powered by a USB connection with a portable battery bank. The problem I'm finding is two fold. The company that makes it has a USB plug from which the line runs to the first digital light bar. A second light bar is in a chain from the first.
See the diagram below:
USB - [IIIIII] CABLE - ========= LIGHT BAR - [ @ @ @ @ @ @ @ @ @ ]
NOTE: There is something in between the USB and light bar that is heat shrinked so i cannot identify what the item is that I need to add.
CURRENT DESIGN: [IIIIII]---------------[ @ @ @ @ @ @ @ @ @ ]-----------------[ @ @ @ @ @ @ @ @ @ ]
I want to quit relying upon their design and switch to a "Y" design with two separate light bars being powered via the USB and power bank. NOTE: (The system they sell me has a remote control.)
I would like to re-design it with two separate cables, one from each light bar. That way i can set the length of each cable specific to what i need.
The light bars have velcro on the back BUT when you go to separate the two pieces, you run a risk of damaging the light bar from the pulling of the velcro to separate the two pieces.
Amy help on this would be greatly appreciated...