Soft-on Soft-off LED Driver

How can I make my 15W LED's have soft on and soft off features through which they start very subtly. Please help and mention every way possible. Operation Voltage :240V(China/India)

by vedant_chawlaa
August 02, 2018

1 Answer

Answer by mikerogerswsm

Interesting question. First you need to drive the leds from dc, ie have a rectifier in the circuit. Then you need to ramp the voltage (or rather current) up and down slowly. This is easy at low voltage but very difficult at high voltage. I'd suggest you reconfigure your lights to low voltage dc, possibly about 20V, and start from there.

+1 vote
by mikerogerswsm
August 02, 2018

I have my LED's at 12 V. How can I ramp the voltage at the start so that it slowly increases?

by vedant_chawlaa
August 03, 2018

You really need to increase the current gradually, either by a dc method or by pwm (qv). Any competent electronics design engineer can be employed by you to do this. He will need to know the local regulations to ensure compliance. Please ensure that anything you market to the public is adequately insulated. mike

by mikerogerswsm
August 03, 2018

Your Answer

You must log in or create an account (free!) to answer a question.

Log in Create an account


Go Ad-Free. Activate your CircuitLab membership. No more ads. Save unlimited circuits. Run unlimited simulations.

Search Questions & Answers


Ask a Question

Anyone can ask a question.

Did you already search (see above) to see if a similar question has already been answered? If you can't find the answer, you may ask a question.


About This Site

CircuitLab's Q&A site is a FREE questions and answers forum for electronics and electrical engineering students, hobbyists, and professionals.

We encourage you to use our built-in schematic & simulation software to add more detail to your questions and answers.

Acceptable Questions:

  • Concept or theory questions
  • Practical engineering questions
  • “Homework” questions
  • Software/hardware intersection
  • Best practices
  • Design choices & component selection
  • Troubleshooting

Unacceptable Questions:

  • Non-English language content
  • Non-question discussion
  • Non-electronics questions
  • Vendor-specific topics
  • Pure software questions
  • CircuitLab software support

Please respect that there are both seasoned experts and total newbies here: please be nice, be constructive, and be specific!

About CircuitLab

CircuitLab is an in-browser schematic capture and circuit simulation software tool to help you rapidly design and analyze analog and digital electronics systems.