Ears are open to all suggestions to improve efficiency with proper justification of course. Thanks guys
I say efficiency in terms of addition/reduction of components. This is a project and extra marks would be awarded if there's indeed a way to do so.What is your definition of efficiency?
Thanks for the suggestion can you explain what you mean a bit more. It is indeed common cathode, thanksIf it's a common Cathode, the ditch the resistors R2 to R8, and put them in the segments a-g.
As Dave says, ditch R2, R4, R6, R8.I say efficiency in terms of addition/reduction of components. This is a project and extra marks would be awarded if there's indeed a way to do so.
Ok understood. Justification for swapping the resistor locations would be to limit current entering the display segments. Looking at my transistor datasheet the Vce rating is 40 V so having those resistors at the collector is pointless. Is my line of thinking correctAs Dave says, ditch R2, R4, R6, R8.
Install resistors in A-G and DP as Dave says. 470Ω (220Ω if the digits are multiplexed).
Unlike a logic gate of opamp unused input, an LED can have a completely floating pin with no problems. Since only one digit is energized at a time, the other three digit's anodes are floating when their drive transistors are off. That is ok; the 1K pullup is not needed.Is my line of thinking correct
IF it is a multiplexed LED display (any particular reason why that detail is a secret?)
AND IF it is common-cathode
THEN the four pullup resistors R2-R8 are not necessary.
IF the segment drive signals are not current-limited externally
THEN you need to add 8 resistors, one for each segment.
ak
Thanks Analogkid it is multiplexed i forgot to mentionUnlike a logic gate of opamp unused input, an LED can have a completely floating pin with no problems. Since only one digit is energized at a time, the other three digit's anodes are floating when their drive transistors are off. That is ok; the 1K pullup is not needed.
ak
depends on what you meant by "efficiency".to improve efficiency
by Duane Benson
by Jake Hertz