Hello.
First, let me say this circuit works as is -- it is a 99 minute timer.
Second: I am NOT a student nor a manufacturer. I am a hobbiest who is struggling with electronics.
Because I have impaired vision, I want to use larger, 2.3inch 7 segment LEDs than the half-inch LEDs that were used in the original circuit shown here.
My new 7 segment LEDs are also common cathode, but they require 7.5 @ 10mA.
My idea is to use either a 9V or 12V supply and use an LM7805 for the PIC and an LM317 adjusted to put out 7.5V (I already know how to do that, so I only need to see how to drive the LEDs from that 7.5V so that I don't blow up the PIC.
Thank in advance for any advice you can give me!
First, let me say this circuit works as is -- it is a 99 minute timer.
Second: I am NOT a student nor a manufacturer. I am a hobbiest who is struggling with electronics.
Because I have impaired vision, I want to use larger, 2.3inch 7 segment LEDs than the half-inch LEDs that were used in the original circuit shown here.
My new 7 segment LEDs are also common cathode, but they require 7.5 @ 10mA.
My idea is to use either a 9V or 12V supply and use an LM7805 for the PIC and an LM317 adjusted to put out 7.5V (I already know how to do that, so I only need to see how to drive the LEDs from that 7.5V so that I don't blow up the PIC.
Thank in advance for any advice you can give me!