|
Websites Found an interesting website? Post the details here and share it with the rest of us. Please stick to websites that are in some way related to our hobby/interest. |
|
Thread Tools |
2nd Dec 2014, 11:54 am | #1 |
Dekatron
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,737
|
Calculating shunts for 'mystery' meters
There used to be a wonderful website by American Amateur, W6BKY, called ‘Wanna Tinker’ which no longer exists, but happily, W6BKY still exists and is his 80th year! The original 'WannaTinker' started with an article in the May 1997 issue of a monthly newsletter for a local Ham Radio club (now defunct). From that modest beginning, WannaTinker advanced to being published in other Ham Radio club newsletters as well as being published in the HamRadio Online website for several years.
Some of the articles on that original website are still accessible, notably a very useful gizmo called the ‘Meter Master’ – a simple device which enables you to work out the internal resistance of a ‘mystery’ meter in order to discover its FSD current, and to calculate shunt resistances, be it for current or voltage. So for example, if you discover that the meter is 200uA FSD and want it to read 10 Amps, you can calculate the parallel shunt resistance. He then explains how to make that shunt. Or if you want the meter to read 12 Volts (or 240Volts or whatever), he shows how to calculate the series shunt resistor. I made one some years ago and have found it very useful. I thought others might be interested in it, and if so it can be found at this link, along with other interesting items: http://w6bky.me/2011/11/30/meet-the-meter-master/
__________________
David. BVWS Member. G-QRP Club member 1339. |