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Author Topic: large seven segment display drive  (Read 393 times)
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I have two 12v common cathode seven segment displays. I need to drive those to get out put for ping sensor. I have seen so many
articles regarding common anode large seven segment displays.

So please help me to drive 12v  common cathode seven segment display
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Hi,

You will need a supply voltage of perhaps 15V (12V will probably not be enough).

What is the max current of the segments?

Do you want to multiplex the 2 displays or not? Less hardware will needed if multiplexing, but displays will be somewhat less bright. You could adopt a 2:1 multiplex ratio (lighting one digit at a time) or an 8:1 to reduce current consumption but also brightness (lighting 2 segments, one from each digit, at a time).

You will need high-side switches, and, if multiplexing, low-side switches also. The low-side could just be npn transistors like BC337. The high side could be PNP transistors (e.g. BC327) with NPN transistors to pull their bases down.

Paul



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I have two 12v common cathode seven segment displays. I need to drive those to get out put for ping sensor. I have seen so many articles regarding common anode large seven segment displays.

So please help me to drive 12v  common cathode seven segment display

Which "displays"? It helps people is they know what you're talking about.

12V displays usually have built-in resistors, etc. so all you need is something to switch them. Common-cathode makes this more difficult.



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