Search found 5 matches

by dstahlke
Sat Jan 29, 2011 5:58 pm
Forum: SparkFun Site Questions/Comments
Topic: Nokia breakout: inductor very hot
Replies: 16
Views: 8233

Re: Nokia breakout: inductor very hot

I ordered it from Digikey. The part number is: M8294-ND (CHOKE RF HI CURRENT 220UH .508A) This thing is huge (compared to the typical size of electronics components) and I ended up having to run wires from the inductor to the board so that I would be able to still mount the LCD on the front panel of...
by dstahlke
Mon Aug 31, 2009 7:04 pm
Forum: SparkFun Site Questions/Comments
Topic: Nokia breakout: inductor very hot
Replies: 16
Views: 8233

cpolley: Interesting. I have no idea why that works. Last week I finally had some time to work on my project again. I figured that I would use the circuit as-is and just ignore the heat. Sure enough, once I mounted the display in a plastic box the inductor fried (I was running it at 3.7v). The funny...
by dstahlke
Thu May 14, 2009 5:28 pm
Forum: SparkFun Site Questions/Comments
Topic: Nokia breakout: inductor very hot
Replies: 16
Views: 8233

Funny, for me it seems to be just the opposite! At 3.7 volts it always gets hot. At 5v it seems that if it is initially cold it will stay cold. If it does get hot though, it will get extremely hot at 5v, even more so than at 3.7v. I think that the inductor is not meant to handle those kinds of curre...
by dstahlke
Fri May 08, 2009 5:36 pm
Forum: SparkFun Site Questions/Comments
Topic: Nokia breakout: inductor very hot
Replies: 16
Views: 8233

Nokia breakout: inductor very hot

I have a Nokia LCD breakout board from SparkFun: http://www.sparkfun.com/commerce/product_info.php?products_id=8600 The page states that the backlight driver should use 243mA at 3.7V. Mine uses about 130mA initially then jumps to 310mA after a minute and the inductor gets hot enough to burn my finge...
by dstahlke
Sun Mar 29, 2009 1:10 am
Forum: SparkFun Product Questions
Topic: how to turn a backlight on or off digitally
Replies: 0
Views: 424

how to turn a backlight on or off digitally

Is there a simple way to turn an LCD backlight on or off digitally? I am using the Nokia breakout board and driving the backlight using a 3.7v LiPo battery. The digital circuitry runs at 3.3v. It seems to me like this could be done with a single FET or transistor but my background in that area is la...