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Low ESR Output Capacitor for REF5010 and REF5025
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magic:
By the way, it seems that you intend to stack 120 of those chips.

Are you sure you don't want to use a single 2.5V reference chip and 120 identical 0.02% resistors to scale its output up to 300V in the same discrete steps?
Kleinstein:

--- Quote from: magic on July 09, 2022, 10:29:17 am ---By the way, it seems that you intend to stack 120 of those chips.

Are you sure you don't want to use a single 2.5V reference chip and 120 identical 0.02% resistors to scale its output up to 300V in the same discrete steps?

--- End quote ---
I abosolutely support the idea of single reference and than stack resistors. Though I would more like start with 10 V and than use only 30 Resistors for the coarse part an a sperate fine part at one end.
The idea with stacking refrence is mainly useful if one wants to measure them individually and this way get a rather accurate step from the sum.
EPAIII:
120 of them stacked? Er, NO! That would cost around $1K and for that much I would rather try to find a used standard that I could repair and get calibrated. NO!

Thirty (30) of the 10 Volt reference chips would get to 300 V. And an additional four of the 2.5 V ones would allow selections in 2.5 V steps all the way up. And, with around 30 of the REF chips in series, that would cost a few hundred. Actually I will probably need to top it off at a bit under 300 V due to the available transformers at reasonable prices.

But I do not understand how one REF5010 plus a bunch of resistors will get me up to several hundred Volts. A Voltage divider could divide the 10 Volts down to, perhaps 0.1 V steps, but I would want to go the other way and multiplying the 10 Volts up, not divide it down. Are you talking about some kind of amplifier circuit with some other IC? An op amp, perhaps? One that allows 300 V supply rail? I do not know of such a chip. Discrete output stage added to an op amp? I can smell smoke now.




--- Quote from: magic on July 09, 2022, 10:29:17 am ---By the way, it seems that you intend to stack 120 of those chips.

Are you sure you don't want to use a single 2.5V reference chip and 120 identical 0.02% resistors to scale its output up to 300V in the same discrete steps?

--- End quote ---
tom66:
Why not just use precision resistors and an op-amp and power electronics circuit (or just a high-voltage opamp)?  That way you only need one reference.
EPAIII:
The idea is to have a moderately accurate Voltage reference that has steps which would be useful for checking and calibrating analog meters. I would like to be able to check at least one scale, perhaps a 100 V or a 250 V one at several points (10%, 20%, or 25% steps) and also check the other scales at least at one point, as high as possible in the needle's deflection. I would probably add a divider to get down to a 1 V level and perhaps to a 0.1V level.

I hope to accomplish this without access to a reference meter that would allow the circuit to be calibrated. I presently do not have such a meter.

Perhaps I dream.




--- Quote from: Kleinstein on July 09, 2022, 01:17:09 pm ---
--- Quote from: magic on July 09, 2022, 10:29:17 am ---By the way, it seems that you intend to stack 120 of those chips.

Are you sure you don't want to use a single 2.5V reference chip and 120 identical 0.02% resistors to scale its output up to 300V in the same discrete steps?

--- End quote ---
I abosolutely support the idea of single reference and than stack resistors. Though I would more like start with 10 V and than use only 30 Resistors for the coarse part an a sperate fine part at one end.
The idea with stacking refrence is mainly useful if one wants to measure them individually and this way get a rather accurate step from the sum.

--- End quote ---
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