Making a voltmeter move on it’s own.

Thread Starter

Jonlate

Joined Dec 21, 2017
118
Humm, 20% accuracy isn’t quite what I was looking for!
Looking at my box design, I think I do have room to squeeze in a Arduino Nano or smaller board, so thinking I will go that way.
A clock with a load of resistors will take up more room than that.
I could even try a WeMos but don’t know much about them at the moment.

I will take out the resistor that’s in the voltmeter and start playing with ones to get a 5volt at full scale one.

Looking forward to seeing it spinnaker!

Thanks for the help
 

Thread Starter

Jonlate

Joined Dec 21, 2017
118
I am thinking of starting off with a 5k resistor.
From what I have read I need something between 4.7k and 5.5k.
Does this sound about right?
 

spinnaker

Joined Oct 29, 2009
7,830
I am thinking of starting off with a 5k resistor.
From what I have read I need something between 4.7k and 5.5k.
Does this sound about right?
Sorry I just don't recall what I used and I am not going to tear the meters apart to find out . ;) Plus my max volatge was 3V. Yours might be 5V or pretty much anything depending on your design.

Try this
https://www.neatcircuits.com/meter-mult.htm


I also added 1K trimmers

upload_2019-3-22_9-19-53.png
 

AlbertHall

Joined Jun 4, 2014
12,345
I am thinking of starting off with a 5k resistor.
From what I have read I need something between 4.7k and 5.5k.
Does this sound about right?
With 5V that would run about 1mA through the meter.
The most sensitive the meter is likely to be is 100uA so I would start with a 47k and 5V and see what the meter reads.
If it reads about 1/10 full scale then you can move to the 4.7k.
 

spinnaker

Joined Oct 29, 2009
7,830
FYI those meters already have resistors so you will likely want to replace them Be very careful as those movements can be easily damaged.
 

spinnaker

Joined Oct 29, 2009
7,830
Here is the schematic and the software. I have included the Diptrace files put also a PDF of the schematic. I have included the PCB design in Diptrace but be warned that I made some modifications in the design after I produced the board. Most notably is up sizing the battery socket. You might want to use a different pic anyway but at least the software will give you some ideas.

It has a lot of features like battery backup, sleep and low battery sense that you might not want to use.

Let me know if I have forgotten something.
 

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Thread Starter

Jonlate

Joined Dec 21, 2017
118
Let me know if I have forgotten something.[/QUOTE]

The circuit board that you made!!
Thanks for all that info I will post pictures when I eventually get it running as I like.
 

spinnaker

Joined Oct 29, 2009
7,830
Let me know if I have forgotten something.
The circuit board that you made!!
Thanks for all that info I will post pictures when I eventually get it running as I like.[/QUOTE]


I mentioned that above. It is included in the zip in diptrace format. I explained why I only included diptrace.
 

Thread Starter

Jonlate

Joined Dec 21, 2017
118
I really appreciate the files, that was said in jest!

I have never tried making my own circuit board before, I suppose this should be my ‘baptism with fire’
Let’s hit YouTube and see what’s the best way to make them.

If all else fails, there is always the proper board makers, it’s just then deciding who to send it to.
 

spinnaker

Joined Oct 29, 2009
7,830
I really appreciate the files, that was said in jest!

I have never tried making my own circuit board before, I suppose this should be my ‘baptism with fire’
Let’s hit YouTube and see what’s the best way to make them.

If all else fails, there is always the proper board makers, it’s just then deciding who to send it to.
There are lots of posts here on actual DIY manufacture of the boards.

The big problem I have with sending it off is you need to get the design working the first time. I don't know how man mistakes I made in design. No big deal as I DIY. Worst that happens is I lose some time and a PCB.
 
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