Pump or just capacitor?

[DP]

Tony, me thinks you need to go to FIRST principles regards meters on HOW they operate. To measure voltage, a series resistor is fitted series with meter movement and this rudimentry meter applied at any two points where voltage needs to be measured. For DC, the circuit through which current flows is cut and rudimentry meter placed between the cut wires so that all the current flows through the rudimentry meter- only in this case the 'heavy' current flow is bypassed through the shunt. I know, you already know all that. But what I cannot understand is, how can you post a picture and state this is how you would measure alternate current. Clealry the following says otherwise

Its so simple but here is a circuit:-

Your drawing is to be found here!!

http://www.allaboutcircuits.com/vol_2/chpt_12/1.html

Clearly the drawing you have cut and pasted is for voltage indication

The text reads

In order to use a DC-style meter movement such as the D'Arsonval design, the alternating current must be rectified into DC. This is most easily accomplished through the use of devices called diodes. We saw diodes used in an example circuit demonstrating the creation of harmonic frequencies from a distorted (or rectified) sine wave.

The reason why a bridge rectifier is used is to present rectified voltage to the meter ELSE the meter movemet will OSCILLATE.


You might want to look at following for ammeter design for DC current measurement
http://www.allaboutcircuits.com/worksheets/meters2.html

Or
http://www.richardsradios.co.uk/Images/mk2diagram.jpg
which is AVO 8 showing both DC and AC current measurement.

 

[DP]

Tony wrote on another thread

This might even prompt you to give me a push on the thanks button!

Can I ask you to do the same for my informative post above? You have to concede I know what I am talking about. By the way, Googling is fun as I did not have to dig out my Elementary Electrical course notes