LED Resisitor on Mains Circuit - Electronic Circuits Projects Diagrams Free

bryan · 7th December 2003, 10:36 AM

I want to add a LED to a switch in a power supply. More or less the same as a neon indicator. I calculate the resistance to be about 5.5K for a mains voltage of approx 117 volts.

Question I have is what is the wattage of the resisitor I should use.

Sebi · 7th December 2003, 12:45 PM

Since the LED voltage around 2V You can calculated with 115V/5500ohm, this is 0.02A, P=U*I, 115*0.02=2.3W, But i recommend for continous use min. 4W. Or You can use X2 type condenser about 100nF with series 100ohm.Both case need antiparalel diode with LED.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

7th December 2003, 10:36 AM	(permalink)
bryan	LED Resisitor on Mains Circuit I want to add a LED to a switch in a power supply. More or less the same as a neon indicator. I calculate the resistance to be about 5.5K for a mains voltage of approx 117 volts. Question I have is what is the wattage of the resisitor I should use.

7th December 2003, 12:45 PM	(permalink)
Sebi	Since the LED voltage around 2V You can calculated with 115V/5500ohm, this is 0.02A, P=UI, 1150.02=2.3W, But i recommend for continous use min. 4W. Or You can use X2 type condenser about 100nF with series 100ohm.Both case need antiparalel diode with LED.