Sjöström Audio DIY forum

Projects => Power supplies => Topic started by: dvb-projekt on February 18, 2012, 04:13:59 PM

Title: SST03 LED voltage
Post by: dvb-projekt on February 18, 2012, 04:13:59 PM
Hi P-A,

the LED in my power-switch needs 12V. I measure only 0,46V at the LED connector X4.
Is the measured voltage normal with the resistor value from the BOM?

Any recommendations?

Best regards,
Oliver
Title: Re: SST03 LED voltage
Post by: peranders on February 18, 2012, 04:57:02 PM
You may adjust R2. If your LED can take approx. 40 mA, then you can omit the R2 but if it's too much you can let current go through R2. 560 ohms may be sufficient.
Title: Re: SST03 LED voltage
Post by: dvb-projekt on February 19, 2012, 11:50:37 AM
i have insert a pot to adjust the voltage to the needed 12V.
Run's perfect! :wink:

Best regards,
Oliver
Title: Re: SST03 LED voltage
Post by: peranders on February 19, 2012, 12:08:09 PM
Notice that this pot is on a deadly potential. I'll recommend that you change to a fixed value when you have adjusted the right current.