water level indicator circuit 7 segment does not work

[david0802]

Hi,can help me see my circuit,why the 7 segment can't work?thank a lot !

[aa232004]

hello, I have it checked.

a few things -

you have used display with common cathod but needed - common anode.

resistor R1  value is to high - reduce it down to 50..60 ohm or keep the 100 ohm but reduce the ON carrent of LED display,

unfortunately you did not read data of the U2 - 7447  - carefully -  pins 3.4.5 should be in High condition( connected to +5 v through resistor 10 kohm f.e),

I hope it helps

best regurds

Michael

[david0802]

thank you for your reply 🙂

but i follow the changing you told me,but it also can't work. Can u help mecheck what is the problem?thank a lot!

[aa232004]

hello,

no problem.

yours LCD display is still Common Cathode, but should be Common Anode as I recommended.

fix it and it gonna be OK

thanks

Michael

[david0802]

Thank you very much,it can work ady

if i want add LED and buzzer in to my circuit,have any suggest?

[david0802]

Thank you very much,it can work already

if i want add LED and buzzer in to my circuit,have any suggest?

[aa232004]

hello, I am glad it helped.

to your questions -

please formulate exactly what  you are trying  to do.

thanks

Michael

[Buechsenschuetz]

I am not the admin of this forum, but PLEASE do not forget that this forum is dedicated to discussions about problems using Ultiboard and Multisim, NOT problems how to design a circuit. There are lots of forums and newsgroups on the web dedicated to circuit design problems. 

[david0802]

ok,thank you for remind