Thus it's not well suited for multiplexing with larger digit count.
Anode driver- ULN2003A (o/p current 500ma per driver pin) and BC327(collector current of 500mA) AND Cathod Driver- ULN2803(collectro current 500ma).
all will be coming under rating. then why not suited as u said.
Will u plaese update the fact ??
I notice that YSD-1100AR7B-15 (I guess that's your LED display) is specified with only 30 mA segment peak current. Thus it's not well suited for multiplexing with larger digit count.
tota30ma x 7 = 210 ma for each digit, then if i use ,HTML:Thus it's not well suited for multiplexing with larger digit count.
HTML:Anode driver- ULN2003A (o/p current 500ma per driver pin) and BC327(collector current of 500mA) AND Cathod Driver- ULN2803(collectro current 500ma). all will be coming under rating. then why not suited as u said. Will u plaese update the fact ??[/QUOTE] It will work just fine. For a 6 digit clock, the average current in the LED's will only be 30 mA / 6 = 5 mA, but that is more than enough for modern LEDs. According to the datasheet, the decimal point uses one string of LEDS, and all the other segments use two parallel strings. I think this means that the peak current for the segments is 60 mA, 30 mA in each string. The peak current for one digit is then 7*2*30 mA + 1 * 30 mA = 450 mA You should have a series resistor for each segment driver to get a predictable current.Don't assume that you really need as high current as possible. In this case you can easily make the current adjustable by making the 15V supply adjustable.
I see no indication that the current rating is meant per LED string. 5 mA average in x6 mux may be too low for bright ambient light conditions.
Thus I think, this display will be best operated in non-mux.
No, the voltage drop across the resistor should only be about 3V (15V - 12V). So 100 Ohms for 30 mA or 50 Ohms for 60 mA.ok std, the series resistor for each segment (2 parallel string) will be 15v/60ma=250, standard 230R.
It will work just fine.
For a 6 digit clock, the average current in the LED's will only be 30 mA / 6 = 5 mA, but that is more than enough for modern LEDs.
According to the datasheet, the decimal point uses one string of LEDS, and all the other segments use two parallel strings.
I think this means that the peak current for the segments is 60 mA, 30 mA in each string.
The peak current for one digit is then 7*2*30 mA + 1 * 30 mA = 450 mA
You should have a series resistor for each segment driver to get a predictable current.Don't assume that you really need as high current as possible.
In this case you can easily make the current adjustable by making the 15V supply adjustable.
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