This is my Volt and Ampere Meter

[bg7nyt]

Click here! You can see it. (http://netkiller.8800.org/ham/meter/index.xml)

This is some pictures.
http://netkiller.8800.org/ham/meter/ham-bg7nyt-1.jpg

[VK2TIL]

Very neat work; you should be proud of it.

What will it be used for; 12/13.8 volt radios or for general testing?

Note; I have taken the liberty of linking to your posting in the Questions & Answers section of this forum;

http://www.qrz.com/ib-bin....457;r=1 (http://www.qrz.com/ib-bin/ikonboard.cgi?act=ST;f=5;t=180457;r=1)

That's a more "technical" section than here and many people who are active there might like to see your work.

[bg7nyt]

VK2TL DE BG7NYT Thank you for reply.

I used 12v switch power supply for radio (YAESU FT-7800R).
actually, those switch power supply is adjustable.
for example 12v you can adjustment 13.8v.
I used 15v too and then adjustment 13.8v.

http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
I usually use the Amperemeter judgement Watt.
for example the following table.
5W = 2.5A
10W = 5A
40W = 8A
......

[VK2TIL]

For that use, you can "expand" the voltmeter scale to make more accurate readings.

These meters are on my home-made power supply;

http://img253.imageshack.us/img253/2851/metersdt3.jpg (http://imageshack.us)

Notice that the voltmeter starts at 10 volts.

If you wish, you can do this by putting a 10 volt Zener diode in series with the meter; you will then have a meter that begins at 10 volts and ends at 20 volts.

You will, of course, have to change the meter scale;

http://img524.imageshack.us/img524/3742/meterzh4.jpg (http://imageshack.us)

You have done a fine job; congratulations.

[VE2NSM]

Cool!

[N2RJ]

Not bad. Maybe you can add some Andersen powerpoles to it and make a distribution panel?

[bg7nyt]

VK2TIL DE BG7NYT

You are right,

My radio's maximum watt is VHF 50W / UHF 40W so 15 voltmeter and 15 amperemeter are best.

[VK2TIL]

Here is one circuit;

http://sound.westhost.com/articles/meters.htm#5

But I just used a Zener like this;

http://img182.imageshack.us/img182/4122/znrmo1.jpg (http://imageshack.us)

If the voltage is less than 10 V, the Zener will block it; at over 10 V the Zener conducts but it "loses" 10 V across itself.

The resistor R will already be in your voltmeter; perhaps inside it.

[bg7nyt]

right, The resistor R inside the voltmeter.

Also, the Shunt Resistor inside the amperemeter.