I am waiting for a response from Littleghost as well. Not planning on ordering any new parts unless littleghost has a better setup.
WHY would common cathode LEDs be dimmer than common anode as you suggest??
I could add more voltage but then its a vicious circle that would perhaps have no better results as per ohms law.
No boards to the trash, no schematics to the trash etc. The set up I constructed is on a perfboard. Maybe adding more LEDs as suggested would brighten up the effect.
Pardon me WHAT?
"WHY would common cathode LEDs be dimmer than common anode as you suggest??"
Your LEDs are dim because they are built that way; this is what the data sheet says and these LEDs are designed to be indicator LEDs....LEDs you look at to see the status of something. I pointed this out in post #227. I did not state a common cathode would be dimmer than a common anode. Geez oh grief.
"I could add more voltage but then its a vicious circle that would perhaps have no better results as per ohms law."
What the hell are you talking about? LED brightness is a function of current. Period. And Ohm's LAW is a LAW. Not a rule of thumb. Not an approximation.
Vsupply = Vled + Vresistor
Vsupply = Vled + IR <---- I controls the brightness of the LED. R controls the current.
rearranging (yes, algebra - should have paid attention in math class)
Vsupply - Vled = IR
Maximum current in the LED is 20 mA, so rearrange and solve for R to achieve that current.
(Vsupply - Vled) / I = R, where R is in Ohms and I is in AMPS
Desired current is 20 mA = 0.02 amps
Vsupply ACROSS THE LED AND RESISTOR = 4.6 volts as you measured, which is because of the voltage drop across the transistor.
Vled = 2.5 from the data sheet
So
R = (4.6 -2.5)/0.02 = 105 Ohms. 105 Ohms is a standard value in the 1% resistor series. Or use the next greater value in the 5% series, 110 Ohms.
This will provide the maximum brightness for this LED. but it will still be dim.
"Maybe adding more LEDs as suggested would brighten up the effect."
MAYBE more LEDs will brighten the effect? MAYBE? What else could possibly happen??????
For sure using a brighter LED will....
My new rule is limiting the theater of the absurd to 15 minutes per day and answering your posts to 15 minutes. The time allowed for posting answers has been exceeded by a factor of 4 today.