Re: Meters

> A week or so back, someone asked about converting DC meters to
> read AC (rf).  SHort answer: connect the meter inside a bridge
> rectifier.  Long answer:
>             +->|-+-|<-+
>             |  + |    |
> 	----+    M    +------
>             |    |    |
>             +-|<-+->|-+

Presumably this is to convert a DC voltage meter to an AC voltage 
meter.  Is there any easy way to convert a DC ammeter to an AC 
ammeter with diodes, etc...?  If you wired two diodes in parallel with the 
cathode of one connected to the anode of the other, but ran one of the 
half-wave rectified diode outputs through a meter before rejoining the 
wires (see below), the meter would be measuring the current in half the 
waveform.  Would the true AC current then simply be 2x (or some other 
simple multiple like sqrt(2)x ) the DC meter reading?

      |     |
  ----+     +----
      |     |

Steven Roys (sroys-at-radiology.ab.umd.edu)