10V Reference (I Did It My Way) No1

[Andreas]

Hello Blackdog,

sorry I do not have a 3458A like Frank. (so probably you should ask him).
My ADC´s which I use have a host program on PC which generates
a CSV out of the binary data which is transferred by the ADCs.
The rest is spread sheet calculation.

With best regards

Andreas

[T3sl4co1l]

I've done this before;



No pictures, unfortunately.

Construction is a copper sheet of modest gauge, bent into a trough, with a piece of copper clad PCB soldered in the middle for deadbug construction of the circuit.  Also soldered to the sheet are the transistor and regulator, at opposite ends.  Since both the regulator and heater carry essentially the same current, heat will therefore be balanced between them when the supply is a nominal 10V or so.  (Under ambient conditions, it regulates from 7V to 18V and "naked" to "wrapped with as much fluffy stuff as I can find".)

Compensation is slow and stable, with a time constant around 30 seconds.  I think it had mild overshoot, but nothing crazy.

Tim

[blackdog]

Hi Heren <=Dutch

Some pictures of the data afther the rebuild of my Quad LT1021CH-5 Reference.
Measuring thime is almost 240 Hour.

The top graph in this picture shows the drift from "0" function (9,6e-07V) <Stupid BenchVue software, code written by hobbyists!!!
1Div. = 1PPM (10uV), the mountains in the graph, the sun is shining in my LAB. 

The bottom graph in the temperature drift @ the LT1021 references.
1Div. = 0,1C, you can see very well when the sun is shining.


Hi Resolution foto link.
www.bramcam.nl/NA/NA-Quad-LT1021-10V-Ref/NA-Quad-LT1021-10V-Ref-Drift-Temp-238H.png

Histogram of almost 240 Hour.



And this is nice...
I isolate the Polystyrene box better with a small towel and the temperatuur in the oven went up, about 0.8C!
And nothing to see at that point at the voltage output.
So the DC graph, indicates for the most part, the drift of the KEYSIGHT 34461a DMM...



I left out the "trim" possibility in this reference, it makes it more stable and its only about 3.8 PPM of from 10.000000
Time to build de Quad LT1021 reference in a nice box.

Kind regarts,
Blackdog

[JohnnyBerg]

And this is nice...
I isolate the Polystyrene box better with a small towel and the temperatuur in the oven went up, about 0.8C!
And nothing to see at that point at the voltage output.

Nice pictures!

May I conclude that keeping the temperature of the oven is not that exiting?
After all, a 0,8°C temperature jump did not change the output voltage.

[blackdog]

Hi JohnnyBerg,

I used 4 selected aged LT1021CH-5 and the LT1021 is already a good part, thats why i good let you see this nice data 

Kind regarts,
blackdog