USB Output Card LED Brightness decreases as more LEDs are lit up

[Masterploxis]

Hello,

as the thread title sais, the more LEDs i am lighting up (for test in controlador.exe) the lower the bright ness of the connected LEDs gets.

I connected 5V external power supply to Jumper Nr. 10. I connected all LEDs to a common positive pole (with resistor). I connected the separate minus poles of the LEDs to the screw connector.

See the attached pictures. Did i connect it in the wrong way or why are my LEDs getting darker the more i light up ?

5237

Cheers
Andy

[kiek]

Hi
This is the way I did it: USBOutputs (http://www.lekseecon.nl/iocards.html#USBOutputs)
Check that.
regards,
Nico

[Masterploxis]

Hi Nico,

thanks for the fast response. I tried that also. Leave J1 open and close J2. Still the same result. The more outputs (minus) connectors i activate with controlador, the darker the LEDs go.

I measured the the 5 Volts from the Power supply - ok.

All the LEDs plus poles are daisy chained (in line) connected to the common plus pole 5V as in my photo. The minus poles go from each LED separate to the single connectors. The voltage stays the same (4,3V) no matter how many LEDs are lit up. But the brightness goes down ; (.

Thanks anyway - and you have very nice website i already visited many times ; )

Cheers
Andy

[kiek]

Hi Andy,


All the LEDs plus poles are daisy chained (in line) connected to the common plus pole 5V as in my photo. .

That's not good... You must put the leds in parallel, each led between 5V and ground with a resistor in series (in-line).

regards,
Nico