Hi there! I am following this: Simple Arduino 7 segment display example – My Blog tutorial to create a simple countdown timer. I want to use this one with a big 7 segment element. 5 volts is not enough to power this one so I want to use of an external power source (12v).
Can I keep using my standard arduino ports to communicate with the 4511 and just hook up a 12 volt power supply to the 4511?
thanks.
rc1985
Can I keep using my standard arduino ports to communicate with the 4511 and just hook up a 12 volt power supply to the 4511?
No you need a transistor to drive the higher voltage.
Thanks for your reply. You mean I need to transform the arduino's digital output to a higher voltage? Can the 4511 then still recognize if the output is high or low? What kind of transistor should i use?
can i use the same one as described here?
The segments take 12 volts (serial leds?). I can just put 12v on 1 segment or on them all and connect the cathode side to ground without a problem.
you can see in the example there is made no use of any transistor.
Furthermore, it shows a common anode display
are you sure? this looks like a common cathode (pin 3 and 8 go straight to ground). I own this unit:
now i see it has a 8 volt forward. So 12 volt is a little too much.. I hope it must be possible to make some simple changes and use this big one instead of the smaller one using this same schematic. I hope you can help me.
thanks
anyone with some ideas on this?
To make things simpler:
this is exactly what i want to do:
except I have common cathodes. Should I just get some common anodes? Or is there a better way?
