You should check which brand of ic, the input voltage high Vih could be a little difference, as the CD4511BM/CD4511BC from ns will be about 70% of Vdd, so if Vin=12V then Vih should be about 8.4V.
You could check Vih of CD4511 on page 3 from the left side in the linked page.
Have you measure the I and Vf of led, and the 12Vdc real voltage?
Assuming that Vcc is 12V, 5 leds and the Vf of led is 2V, (12V-(2V*5))/120 ohm=2V/120 ohm = 16.667mA
Is that what you arrange the led display that you used 5 leds to be a segment?
Hello,
The Vcc is 12.42 right now is adapter SMPS after that there will be transformer!
total current is 222mA for 0 in 4 digits!
the voltage across string is 9.96V, Vf of led is 1.92V, current per segment is 8.89mA and voltage across resistance is 1.8V.
Here is the circuit only Vcc at 12V, and input with pull down of 10k and input of 9.4K same!
One thing more the input wire i have is cable of 5 wires. in circular color coded (I don't know the Name)
what will be the maximum length of input wire to work on it?
You may want to do a Google search for "multiplexing 7-segment displays". This technique allows you to use 7 (or 8 if you are using the decimal points) data lines common to all of the digits, plus one select line for each digit.
Hello,
There is some problem as THE PLC work in 24V and this circuit at 12V.
The Input are connected to Gnd with pull down of 10K, when the inputis connected to 12V it work as BCD 8421 on display.
But when i use external 24V the Gnd of both are common and the 24 to input the signal does not work well.
how to connect both of PLC 24 nad internal 12V led display together