I went and oederd some red ones from Jameco. They are supposed to be 1.7v. Plus they are common annode so I have more options for powering them.


What I should have done was buy some logic level FETs too. Too late now. Maybe I can find some one ebay?? I hate paying $10 for shipping. Any tips on what part numbers to search for?

 

The main thing to check with displays is the luminance (maybe called brightness or efficiency) it should be listed in uCd or mCd for the display.

Some of the new 7-seg displays have really nice brightness and don't need much current to give a great visibility display.

 

The main thing to check with displays is the luminance (maybe called brightness or efficiency) it should be listed in uCd or mCd for the display.

Some of the new 7-seg displays have really nice brightness and don't need much current to give a great visibility display.

What's a good brightness #?

 

More is better. I only buy single LEDs now when they are >1200 mCd, usually preferring >5000 mCd when possible.

You won't get 7-seg displays in that high a light output but >100 mCd would be a good start, and like I said the higher the better.

Really what it means is that you can use the LED or display at a very low current and still get a good visible (indoor) result.

 

Maybe a small serial TFT display would be better than 6x 2-digit LED displays. If you want to produce a PCB, it is cheaper for sure.

In the past, 8-digit or even 12 digit LED display assemblies existed. There are not many of these available now. There are some 8-digit dot matrix displays, which are very expensive. Most common are 4-digit multiplexed 7-seg displays.

Most calculators etc. use LCD these days.

 

More is better. I only buy single LEDs now when they are >1200 mCd, usually preferring >5000 mCd when possible.

You won't get 7-seg displays in that high a light output but >100 mCd would be a good start, and like I said the higher the better.

Really what it means is that you can use the LED or display at a very low current and still get a good visible (indoor) result.

The problem is sometimes they rate them in ucd and sometimes in mcd and sometimes you find that fom the same supplier!