voltmeter with 7107

[nohutpilav]

Hello everyone,
I'm new to this site. I'm sorry if I'm wrong. I'm designing a voltmeter with the 7107 integrated.
I implemented a circuit I found on the internet in Proteus simulation and it worked.

However, I can only measure in the 0-200V value range.
Although I applied the resistance change written on the site, my voltage capacity does not reach 2kV.

Please help.

 

[danadakk]

Is your 2KV DC only or does it have a lot of noise ?

How do you confirm you are feeding exactly 2KV to the resistor divider input path
for the 7107 ?

Your 2KV divider, what are the resistor tolerances ? Are they clean, no residues on
them ?


Regards, Dana

 

[nohutpilav]

Is your 2KV DC only or does it have a lot of noise ?

How do you confirm you are feeding exactly 2KV to the resistor divider input path
for the 7107 ?

Your 2KV divider, what are the resistor tolerances ? Are they clean, no residues on
them ?


Regards, Dana

Hey dana. I mean I can only see voltage up to 200V on the screen. I can't even see 201V on the screen or 300V or 400V

 

[KlausST]

Hi,

you need to open the switch at D1.1.

Klaus

 

[nohutpilav]

No, this should not be my solution. When the input voltage is above 200v, I cannot see a value on the screen.

 

[FvM]

To measure voltage above 199.9 V, you need to change the input attenuator and get 1999V range.

 

[danadakk]

No, this should not be my solution. When the input voltage is above 200v, I cannot see a value on the screen.

The 7107 blanks its screen when in overrange, exceeding 200 mV Vin.


Regards, Dana.

 

[KlausST]

Hi,

No, this should not be my solution. When the input voltage is above 200v, I cannot see a value on the screen.

I guess you have a reason to say so.
But I would be very surprised if the display shows more than 199.9 as long as the D1.1 switch is closed.

*****
Besides this, you wrote

Although I applied the resistance change written on the site,

but
* we don´t know which site you refer to
* nor do we see where and how you "applied the resistance change".

Klaus