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

Originally Posted by Giggabite

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

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

Originally Posted by Giggabite

Im confused ...

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?