Re: Electrometer design? (fwd)

[Steven Roys <sroys@xxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 05 Jul 2004 21:22:23 -0300
From: Antonio Carlos M. de Queiroz <acmdq@xxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Electrometer design? (fwd)

High Voltage list wrote:

> From: Malcolm Watts <m.j.watts@xxxxxxxxxxxx>

> I am currently examining a design which appeared in the July 1999
> Amateur Scientist section of Scientific American with a view to
> building several. The circuit is basically a transconductance amp
> which amplifies tiny currents which are then converted to a voltage,
> rectified and peak detected. I suggest having a look at that design
> and possibly throwing away the current set of electronics if it is
> too difficult to repair (I suspect it isn't ;)

This is a possibility. But I would like to keep the electronics,
that has a computer interface that can send the data through a
serial link for processing. The damage was caused by a bad design
combined with lack of attention of a student. At the back of
the instrument there are two pairs of identical connectors, one
for a voltage output to a meter, and another for a power supply.
If the power supply is connected to the wrong connector, the
device is immediately destroyed...

Antonio Carlos M. de Queiroz