I just use 3 4.7K to 24V
so, across 4.7 k it was 8V.
the input to CD4511 is not fine it make all logic to 8 when original 12V of CD4511 is taken it work fine 4 in display, why this is happening?

 

So, you mean to say 24V to 12K(up)+10K(down) ?
and is there any pull down or input requirement of another input resistance to CD4511 ??

Just connecting the common pins to the BCD input of CD4511, no need for other resistors.

 

I just use 3 4.7K to 24V
so, across 4.7 k it was 8V.
the input to CD4511 is not fine it make all logic to 8 when original 12V of CD4511 is taken it work fine 4 in display, why this is happening?

So you want the inputs using both 12V and 24V?
If do so then the resistor should be recalculate.

 

So you want the inputs using both 12V and 24V?
If do so then the resistor should be recalculate.

The circuit work in 12V external power supply, and PLC with its own supply.
How CD4511 should read the LOGic from PLC?

 

Actually, i was doing this with puc micro but it was becomng complicated for 4 digits

easy have done that with plain 16f54

2x4 with 16f884 or 16f57

 

easy have done that with plain 16f54

2x4 with 16f884 or 16f57

PIC16f877

 

serial 7seg module 16f54

 

PIC16f877

that also works.

8bits for digits, 5 for sinks, there are 5digit modules but uncommon
you could use 2x 3 digit with 6x multiplex

 

 

that also works.

8bits for digits, 5 for sinks, there are 5digit modules but uncommon
you could use 2x 3 digit with 6x multiplex

Did you see that the TS used 5 leds to be one segment in #21.

 

Did you see that the TS used 5 leds to be one segment in #21.

not well then needs Mosfets or ic driver, at this voltage also BJT could be used

 

What is the use of 1N4148 Small Signal Fast Switching Diodes , Here??
BCD AT 12v how, 10.273 getting here?
and 1k resistance?

Did you see that the TS used 5 leds to be one segment

Yes, We can change it after but question is bcd from PLC

 

Operating voltage 24v
PLC mitusbhi 202hcpu
Output card qy41 cards 32 bits
ladder programming

 

What is the use of 1N4148 Small Signal Fast Switching Diodes , Here??
BCD AT 12v how, 10.273 getting here?
and 1k resistance?

Yes, We can change it after but question is bcd from PLC

If you just using 24V to be the input signal then using 12K and 10K should be work.

If you using both 12V and 24v then the new voltage divider was designed for that, the diode was designed to separated the 24V high voltage and 12V low voltage.

10.273V:
Vo = (12V - 0.7V)*(10K/(1K+10K))
= 11.3V *(10K/11K)
=11.3V*0.909
= 10.272V

 

the diode was designed to separated the 24V hi voltage and 12V low voltage.

What this mean?
OK, in schematic there is 24V and 12V BCD format, but in real there will be 24V only!
and after this the BCD is to be given in CD4511

 

What this mean?
OK, in schematic there is 24V and 12V BCD format, but in real there will be 24V only!
and after this the BCD is to be given in CD4511

So using 12K and 10K, that's all.

 

If you using both 12V and 24v

What does both mean here?
The CD4511 is connected to 12V and as you know PLC work in 24V so, there should be reference in between circuit to measure high and low , how CD4511 will sense the 24V logic from PLC?

 

What does both mean here?[/qoute]
Because you asked too many times when I said that you could used 12K and 10K, but you still not satisfy, so I think maybe you need to use two powers.
The CD4511 is connected to 12V and as you know PLC work in 24V so, there should be reference in between circuit to measure high and low , how CD4511 will sense the 24V logic from PLC?

Unless you go to measure the real voltage of BCD from PLC, otherwise I will treated as 24V output voltage level, and you just ignore about how the CD4511 reading the data from PLC, you just feed it that the voltage of signal <=12V then it's ok when you used 12V for Vcc.

 

Hello,
I think the problem is solved.
Just know there was 24 transformer with rectifier 4 Diode!
it give 24V DC it was without any capacitor when i place small 22uF.
It gives around 34V. so i placed 4.7K 4 series i get 8V and both supply 37V and 12V gnd as common.
after this the BCD from 24V was succesful.
I got the importance of C in Rectifiers.
but what was the problem which was there due to absence of C 22uF the riple in CD4511 input?

 

Hello,
I think the problem is solved.
Just know there was 24 transformer with rectifier 4 Diode!
it give 24V DC it was without any capacitor when i place small 22uF.
It gives around 34V. so i placed 4.7K 4 series i get 8V and both supply 37V and 12V gnd as common.
after this the BCD from 24V was succesful.
I got the importance of C in Rectifiers.
but what was the problem which was there due to absence of C 22uF the riple in CD4511 input?

Missing the 22uF that the CD4511 input will get a 100/120Hz pulse voltage, and that will interfering the normal digital signal.