Im looking for a Common Cathode 7 segment display !

That operates at 12 volts . I have been looking everywhere for these and ive noticed they are not easy to find. Please help . I HAVE BEEN WORKING ON DESIGNING A LIGHT AND DARK SENSOR which when darkness falls , a relay operating at 12v will turn on an analogue 555 timer circuit . This timer will then trigger a lamp after 5 seconds. Ultimately, the pulses from the op amp will also feed into two chips a 4511 and 4510 bcd . These chips will then be connected to the common cathode 7 segment display . If anyone can assist in linking me up .

thanks

Giggabite said:

That operates at 12 volts . I have been looking everywhere for these and ive noticed they are not easy to find. Please help . I HAVE BEEN WORKING ON DESIGNING A LIGHT AND DARK SENSOR which when darkness falls , a relay operating at 12v will turn on an analogue 555 timer circuit . This timer will then trigger a lamp after 5 seconds. Ultimately, the pulses from the op amp will also feed into two chips a 4511 and 4510 bcd . These chips will then be connected to the common cathode 7 segment display . If anyone can assist in linking me up .

thanks

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So why cant you design the cct so that the leds trun off a 5v supply?
The 4511 will happily run from a 5v supply

Chippie said:

So why cant you design the cct so that the leds trun off a 5v supply?
The 4511 will happily run from a 5v supply

Click to expand...

Im confused ...

Giggabite said:

Im confused ...

Click to expand...

I'm confused as to what you are trying to achieve here........Are you wanting to clock the displays so that each time it turns light/dark they count up?


The 7seg displays are common cathode Yeah? ergo the 7 anodes are fed from the outputs of the driver chips...if the chips are fed with a 5 volts supply, the cathode end of the 7 seg display is then connected to ground....No 12 volt supply in sight...You will need a 5v reg to drop the 12v main supply to 5v using a 7805....Whats the problem?

The attached drawing shows how to hook up a 7 seg display to a 4511.
The 4 binary inputs will be replaced by your dec/binary counter....which in turn is triggered by the op amp?