12v // Seven Segment // Arduino // Max7219 // DLN2981

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kelvinmead

Joined May 15, 2011
30
Hi,

I'm building a circuit using a large 12v seven segment display (3 of) and i wish to have the counting part of the circuit done by an arduino, and the segments driven with a max7219.

the segments are common cathode, so i can't use the easier TPIC6B595 to shift and carry the larger current.

so i have to use a driving version of the usual ULN2803 and this brings me to a DLN2981... of which i can't seem to find a supplier with stocks on hand... so whilst i await the chip to fall on my doorstep, what alternatives can i use.

I guess that i can drive each line singularly with a standard NPN transistor PN222A


5V -------> 5V -------> +12V> +12V ---------------> GND
ARDUINO > MAX7219 > NPN > SEGMENT DISPLAY > GND

seem logical?
 
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