connecting LEDs in parallel

k7elp60

Joined Nov 4, 2008
555
And, of course, there's the occasional mHz frequency, when the poster meant MHz.
I wish to apologize to the members of this website that posted to this thread. First let me correct the count of LED's on my post. I said there were 10 when in fact the picture has 12. The second thing I made an error in was the symbol or notation for milliamps.
I posted Ma, when it should be mA. The other error is I stated the current in the LED's of the photo was about 1.5mA. In fact it is the individual LED current is in the uA's. The battery powering the cross is in fact a CR2032. There a 220 ohm 1/8w resistor in series then to the parallel bank of LED's. I had forgotten about the battery's internal resistance which by it self limits the current. Looking at the data sheet for the battery I read the normal load is a 15k ohm load or 0.19mA
 

WBahn

Joined Mar 31, 2012
24,695
How many microamps per LED? 30 uA versus 300 uA is significant. If you still have the cross, it would be nice to know what the voltage drop across the 220 Ω resistor is.
 

tranzz4md

Joined Apr 10, 2015
314
.... individual LED current is in the uA's. The battery... CR2032. There a 220 ohm 1/8w resistor in series then to the parallel bank of LED's. ....internal resistance which by it self limits the current.... load is a 15k ohm load or 0.19mA
What I see, and like, and can quickly understand, is that pic of the little cross. Those LEDs are not noticeably varying in brightness, relative to each other. How bright they are "absolutely" is unknown, but I'm under the impression that they're bright enough to fill their purpose, which is all that actually matters.

Funny; with graphics, block gains, thumbdrives, voice to text and all, how people still hafta use abreviations and stuff so much. I won't hold it against you if you spell stuff out,,,, er at least I'll try...
 
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k7elp60

Joined Nov 4, 2008
555
How many microamps per LED? 30 uA versus 300 uA is significant. If you still have the cross, it would be nice to know what the voltage drop across the 220 Ω resistor is.
I made about 6 of these crosses. The white one has 113mV(millivolts) drop on the 220 ohm resistor, The blue one has 240mV drop on the 220 ohm resistor. Both colors are illuminated quite well and can be seen in a lighted room about 10 feet away. I tried shorting the resistor on both color of crosses and I could see an increase in brightness. I wish i could take more accurate pictures with my smart phone.
 
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