FreeTrack Forum

Welcome, you're not connected. ( Log in - Register )

RSS >  SFH485P power
fosamax #1 06/11/2008 - 22h32

Class : Apprenti
Posts : 1
Registered on : 17/10/2008

Off line

I am thinking of using SFH485P ir leds, they are 3v 100mA each.
Which battery?, and resistors?

3 point cap btv.
Edited by fosamax on 06/11/2008 at 22h32.
benmeijer #2 06/11/2008 - 22h54

Class : Habitué
Posts : 208
Registered on : 19/07/2008

Off line

Take a look here my build: http://forum.free-track.net/index.php?showtopic=466&page=4#8487

1.5 Vf is enough (3Vf is for high freq. pulsing leds), 50 mA current

so if you use 3V from battery use 3 * 30 Ohm resistors
tristan68 #3 11/11/2008 - 07h32

Electronicien en chef
Class : Electronicien en chef
Posts : 651
Registered on : 10/07/2007

Off line

Hello


1.5 Vf is enough



It's not only enough, it's the operating value.

TRYING TO OPERATE THE SFH485P AT 3V IS AN ERROR. YOU WILL FRY THEM


Also 100ma is a max value.

Please use 75 mA max to power them.
If you use 100mA with freetrack your leds will be overpowered.

About the resistor value, please use the led wizard on the web frontpage, and provide the power supply you plan to use and your leds characteristics (1.5v and 25 to 75 mA, depending of your webcam setup) and it will provide the resistor values.

cya
DButler #4 12/11/2008 - 13h32

Class : Apprenti
Posts : 2
Registered on : 12/11/2008

Off line

Hi all, I have ordered and should receive today 3 SFH485P LEDs and a 30 Ohm resistor. I plan to use a 5VDC cell phone charger as the PS. With the resistor and the LEDs wired in series, sholdn't that work?

Thanks in advance.

DB

 >  Fast reply

Message

 >  Stats

1 user(s) connected during the last 10 minutes (0 member(s) and 1 guest(s)).