Talk:Ayrton shunt

This article contains several serious errors and is misleading. Sentence 1: reference to high resistance is wrong; resistances are typically quite low, in any case, no higher than with a MBB switch. Sentence 3: it is not more accurate than a circuit with a MBB switch if attention is paid to keeping contact resistance low enough in the latter case. Par. 2: badly worded; wording is more appropriate for the circuit with the MBB switch. Last sentence is false. Par. 3: Switched shunts such as the Ayrton are rarely used for currents above 10 amperes. I suggest the following rewrite: "The Ayrton shunt or universal shunt is an arrangement of switched resistors used to increase the current range of a galvanometer or ammeter. It is an improvement invented by William E. Ayrton over the obvious (simplest?) circuit shown in Fig. 1, which requires a make before break switch to avoid damaging current surges through the meter movement when switching ranges. If the switch ever fails to make before break, the movement can be destroyed.    The Ayrton shunt, shown in Fig. 2, does not require a make before break switch. For example, assuming a movement with a full-scale voltage of 100mV and desired current ranges of 10mA, 100mA, and 1A,the resistance values would be: R1=9 ohms, R2=0.9 ohm, R3=0.1 ohm. (If the meter movement resistance is less than 1000 ohms, R1 needs to be adjusted slightly.)     Switched shunts such as the Ayrton are rarely used for currents above 10 amperes." Derfnac (talk) 02:37, 29 April 2016 (UTC)

update
After sleeping on it, I withdraw some of my previous critique. In the case of a galvanometer, constant damping can be an advantage. And then the high resistance is significant. I have thought of a better terminology for what I previously called the obvious circuit. Let's call it the parallel circuit.Derfnac (talk) 16:30, 29 April 2016 (UTC)

3 May 2016: Since the article is a stub, I have merged it into the article Ammeter, with some further rewriting. I still need to import the figure from the stub article. Then I need to remove the stub; how do I do that? ```` — Preceding unsigned comment added by Derfnac (talk • contribs) 20:34, 3 May 2016 (UTC)

Merging stub into another article.
I have merged the "Ayrton Shunt" stub into "Ammeter". Now I have some questions. 1. I want to copy the line drawing but have had no luck following the instructions. What is the simplest way to copy an image from one article to another? 2. After that is done, the stub needs to be removed. How do I do that or who does it. 3. How can I assure that a search for "Ayrton Shunt" will lead to "Ammeter"?

Derfnac (talk) 01:07, 11 May 2016 (UTC)


 * for the first question, simply copy and paste  into the appropriate place. For the second and third questions, please see Wikipedia's guide to merging, specifically steps 4 to 9. Rotideypoc41352 (talk) 03:55, 11 May 2016 (UTC)