[SOLVED] 74HCT14N need it to operate in the opposite way.

[3dprintingtech]

Hi All

I have used a 74HCT14N for a circuit I have designed (not the best with electronics but learning) i was advised a 74HCT14N would do what i want but it does the opposite i have a photo interrupter that i want to turn an LED on when it is interrupted.

using the 74HCT14N when it recives a HIGH feed from the interrupter the LED is on when it receives a LOW feed (i block the signal) it turns off. is there a Cmos that operates the other way round ie turns on with a LOW and off with a HIGH?

thanks all

 

[doraemon]

Hello!

If you want people to reply, you should consider sending a schematic of what you did. There
are many ways of wiring even a simple inverter. It depends whether the LED is connected
to the anode or to the cathode, it also depends on how the input is wired. What is your
interrupter? Is it a simple photoresistor? Do you associate it with a resistor at the input of
the gate or is there a more advanced circuitry between the detector and the gate?
If it does the opposite of what you want, it may be precisely because it's an inverter. In this
case use another gate serially (the 7414 has 6 of them).

Dora.

 

[3dprintingtech]

yeah should have thought of that one this is how i have it wired at the moment(i have tried a few other ways which didnt work)
the interrupter is just a phototransostor (**broken link removed**)

hope you able to help from this

- - - Updated - - -

ah i wasnt sure what you meant when you said "In this case use another gate serially (the 7414 has 6 of them)"
but then realised what you meant and tried it its now working as i wanted.

Thanks for the help it does only seem to have 2.6v across the led and its not very bright compared to wiring it to the 5v in what could cause that.