Do you need the brightness that 25 to 30 mA will make? If not, I think you ought to be able to set the segment current with resistors and go with, say 10 mA per segment. If that's all you're using the 78L05 for, then you'll be safe at 70mA max. as long as the input voltage is not too much. 10V in - 5V out = 5V; times 0.07 = 0.35w. Probably tops for the TO-92 package, but this gives some idea of what you're looking at.
Bob Bell
-----Original Message-----
From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Don Caprio
Sent: Wednesday, March 11, 2015 1:53 PM
To: n8vem...@googlegroups.com
Subject: [N8VEM-S100:6514] 7805 Package choices
Hey brains I have a question.
I'm designing a 5V circuit. Considering the 78L05 (TO-92) and 7805 (TO-220).
The L05 is rated at 100ma while the 05 comes in 1a and 1.5 versions.
Is there anything in between? 100ma is not quite enough while the 7805 is overkill.
Space is a concern so I like the TO-92 package.
If I'm reading the datasheet right for a 7 segment display it draws 25-30ma for each segment? Thats a current draw of 250ma if all segments are lit.
Therefore I may have
to use the 7805/C or change my design to use dual state LED (17-22ma) instead of the 7 segment LED.
--
Don Caprio
ilv...@gmail.com
--
You received this message because you are subscribed to the Google Groups "N8VEM-S100" group.
To unsubscribe from this group and stop receiving emails from it, send an email to n8vem-s100+...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google Groups "N8VEM-S100" group.
To unsubscribe from this group and stop receiving emails from it, send an email to n8vem-s100+...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.