The volt box is likely to be a voltage divider that was used to divide a
voltage to be measured down to a value within the measurement range of a L & N
potentiometer (not the 3 terminal component but the type that sets up the
current in a series string of resistors to a known vale by comparing
Vibrating capacitor non contact field probe in feedback loop to create a
voltage follower:
https://www.monroe-electronics.com/ESD/pdf/244a_m.pdf
Bruce
>
> On 23 March 2018 at 15:12 Neville Michie wrote:
>
> Improvise by holding a metal disk over an electronic
Electrostatic voltmeter?
Either the classical version or the modern electronic variant perhaps?
Bruce
>
> On 23 March 2018 at 13:33 "Dr. David Kirkby"
> wrote:
>
> I want to measure a high voltage, but put minimal load on the circuit.
> Looking at
A method in use 40+ odd years ago for measuring atmospheric electric fields was
to use a slotted rotating disk rather than the rotating cylinder.
A matching stationary or counter rotating disk IIRC was used either in front or
behind the rotating slotted disk the the sensing disk was behind
The Keithley model 640 was a vibrating capacitor electrometer.
It was available in the 1970's.
Bruce
>
> On 04 March 2018 at 06:34 george wrote:
>
> Hi all
>
> To the best of my memory Keithley never made vibrating reed
> electrometers, the only one that I
1) Reverse the supplies on U4 (in real circuit reversed supplies will fry the
chip.)
2) Add 10k in series with reset switch
3) Swap connections to U4 inputs.
4) Use series shunt switch for reset switch as used in an actual 3458A.
Once done together with swapping in LT1220 for LT1225 rest works as
Why do you think that the datasheet is wrong?
Its the same as the 1989 version.
A lot of the early wideband opamps didn't have high open loop gain.
Even the LT1220 only has about 7 - 15x more gain at rated load.
The LT1220 has a a pair of cascaded complementary symmetry emitter followers in
Attila
Some insight can be gleaned by using a single pole model for an opamp
configured as an integrator and deriving the expression for the output signal.
Look at the non linearity in the output.
Look at the voltage at the inverting input.
The effective impedance at the inverting input due to
08:45 Bruce Griffiths <bruce.griffi...@xtra.co.nz>
> wrote:
>
> Moin attila
>
> I'd start with simulating and understanding the integrator in the 34401A,
> its a little simpler but still has a coupe of opamps in the integrator. Then
> analysing the GBW requir
Moin attila
I'd start with simulating and understanding the integrator in the 34401A, its a
little simpler but still has a coupe of opamps in the integrator. Then
analysing the GBW requirements of the various opamps used in the HP3458A shoul
become somewhat clearer.
Bruce
>
> On 24
Result of nonlinearity and dc offset combined?
Bruce
>
> On 19 January 2018 at 00:57 "David C. Partridge"
> wrote:
>
> Starting with a warmed up Prema 6048, if I power it off and then on,
> select
> 20V DC range, 4 second integration and connect to
than using a constant dimension of fibers.
>
>
> On Mon, 17 Apr 2017 05:35 Bruce Griffiths, <bruce.griffi...@xtra.co.nz
> mailto:bruce.griffi...@xtra.co.nz > wrote:
>
> > >
> > There's little out there on the frequency dependence of d
s, measured on a real world material? It would tell me a
> lot.
>
>
> On Mon, 17 Apr 2017 04:19 Bruce Griffiths, <bruce.griffi...@xtra.co.nz
> mailto:bruce.griffi...@xtra.co.nz > wrote:
>
> > >
> > Hook is merely a manifestation
A CLD is merely a JFET with the gate connected to the source.Sometimes a source
resistor may be included with the gate connected to the opposite end of the
resistor to the end connected to the source.
Bruce
On Monday, 30 January 2017 12:12 PM, Jerry Hancock wrote:
Laser welding should work for either similar or dissimilar materials.At one
time microwire PCBs used stainless steel wires were welded to stainless lands.
Bruce
On Saturday, 29 October 2016 1:39 PM, Dr. David Kirkby (Kirkby Microwave
Ltd) wrote:
On
Calibration of a 34401A is done electronically, however one needs to know the
calibration security code.If unknown one needs to open the meter to enable
calibration and then reassemble it and complete the calibration. The factory
default calibration security code is HP034401 only 034401 need be
Its certainly a good way to quickly check if anythings drastically wrong and
one could even compare them with a known source such as an LM317 based
regulator with no ADJ pin bypass. If one can hear the noise then its possible
that a sound card could make some meaningful measurements of the
I've used a pair of minicircuits phase modulators, a low noise OXCO, and a
Timepod to do this.The phase modulators work best with about 9V input.The noise
of my E3610A's is clearly evident as is the noise of an LM317 based regulator
with unbypassed ADJ terminal.To achieve lower system noise a
Why?The ADA4522 is unity gain stable with about 60 degrees of phase margin.The
equivalent output inductance at unity gain is about 0.5u
50 ohms in series with the 1uF output capacitance ensures an overdamped
response.
Bruce
On Saturday, 9 April 2016 11:20 PM, "acb...@gmx.de"
In order to understand the dynamics of the LTZ1000 temperature
regulation loop better in order to estimate the chip temperature
response due to ambient temperature fluctuations, I am attempting to
produce a model of the thermal impedance of the chip by fitting a Foster
RC ladder (later
Frank Stellmach wrote:
Dave,
well the schematic is the same as in the LT specification.
My PCB is a prototype, and I would not like to publish it, because it
contains several bugs.
One one those bugs led to the first change of the initial LT
specification, i.e. I discovered the parasitic diode
Dick wrote:
I need a little circuit help here -- I'm looking at the schematic of the
chopper amp, A5A4, and I'm trying to figure out if this amp is inverting or
non-inverting for DC signals, that is from pin 6 input to pin 4 output. I'm
looking at the simplified diagram on page 102 of the PDF
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