I bet $100 that mini actually works, and is much better!
Your standard looks really good.
How much are you selling them for?
Care to trade?
I have an awesome voltage standard with great claims, that is even inspired by the almighty God.
Richiem, I took the liberty of plotting your data. See attachment. JanI mentioned on the LTZ1000 thread that I was interested to see what Awesome14's D-105 could do so I was buying one. It came yesterday. In the interest of more light and less heat, here is what I've found so far. The results are not metrology lab measurements -- they are a guide only, but I've provided enough info to make the results useful. One note -- I have thought for a while that my HP 3458A is reading 10VDC about 6ppm high, although it is in spec....
Calibratory D-105 10V standard evaluation, started on 2-7-15
Instruments used in evaluation:
— HP 3458A, calibration checked on 7 Aug. 2014, by Keysight in Loveleand — no adjustments made, found to be completely in spec; this is the standard model — 8ppm ref board. Used to monitor 10V standard outputs. 3458A powered on for last 6 days; internal temp 36.5 °C. ACAL 1 (DC) run at 4:30PM. NPLC=60, NDIG=8
— HP 3456A, cal’d against HP 3458A. Used for monitoring ambient temps with Pt100 RTD.
— Heath 2718 Linear Triple Bench Supply — each 20V supply powering one standard..
— Geller SVR (not the temp comp unit), purchased in 2007, used for approximately 12 hours total since then up to this time. On for the last 8 hours (included in total of 12), since 8AM with 15VDC power. Geller’s 2007 certificate says 10.000 00V, Tolerance 5ppm/°C, 15ppm/1k hrs. Cal’d at 23°C ambient.
D-105 unboxed in lab at 4PM. Connected to bench supply at 14.5VDC, initial ambient temp at case 23.0 °C. Ambient measured immediately adjacent to and in between the two standards, all sitting on top of an HP 8904A that was powered off — makes a handy stand with some thermal mass.. D-105 output started a few hundred microvolts below 10V, quickly rose to 10.000 05VDC. Calibratory’s certificate says 10.000 0014V, cal’d at 20°C ambient.
Both the Geller SVR and the D-105 outputs are connected with 24ga. solid copper insulated wires (old-school telephone extension wire) to gold flashed dual banana plugs to ease connections to the 3458A. The wires are soldered to the Geller SVR and clamped in the gold-flashed bindind posts of the D-105.
Elapsed time Ambient Geller SVR D-105
for D-105 °C
0.6 hr 23.5 10.000 060 10.000 058
3.4 hr 22.9 10.000 071 10.000 068
5.3 hr 23.6 10.000 060 10.000 066
6.4 hr 23.8 10.000 053 10.000 068
Overnight break in measurements with lab cool-down to thermostat set 66°F, reheat in AM to 71°F; standards left powered on.
20.1 hr 22.4 10.000 092 10.000 078
22.5 hr 22.5 10.000 088 10.000 078
Moved to warmer location on top of HP 3456A, standards and RTD grouped as before.
22.8 hr 28.9 10.000 017 10.000 047
23 hr 29.3 10.000 002 10.000 042
24 hr 29.5 9.999 997 10.000 043
Standards powered down. Will begin from room ambient start in 18 hours or so.
At this point, a simple "box" of drift v. temp shows that average drift for the D-105 is approximately 0.5ppm/°C; the Geller SVR average drift is approximately 1.4ppm/°C (pretty good).
Well, selling is perhaps a big word. I made one for myself, and have gotten 11 boards. I made 7 boards compete, of witch I have sold 3 for € 14,50 + postage. That boils down to the price of the components + the boards.
I also can offer the boards, without components for €3,00 + postage. The REF5025 is pin compatible with the LT1021. Could be a nice experiment.
no offense to the gentleman who makes the alternate ref mentioned here.....but why do people keep buying these things w/o seeing ANY specs or data.....
Generally surface mount REF IC's aren't as stable as their through hole counterparts.....
no offense to the gentleman who makes the alternate ref mentioned here.....but why do people keep buying these things w/o seeing ANY specs or data.....
Generally surface mount REF IC's aren't as stable as their through hole counterparts.....
no offense to the gentleman who makes the alternate ref mentioned here.....but why do people keep buying these things w/o seeing ANY specs or data.....
Generally surface mount REF IC's aren't as stable as their through hole counterparts.....Is that just due to mechanical stress (where does that come from?) or are other factors at play?
@JohnnyBerg
I am most def. NOT trying to admonish you or your REF. I can't fault it's design. My comment was meat more towards HiGhVoltage. He seems to be ordering every ref he finds, w/o really getting the facts. So he is going to be disappointed, or at the lest not really have a basis for testing it when it arrives. That most certainly isn't the manufacturers fault.
I did not ask for help. I found this miserable thread already started, disparaging me and my product, based purely on conjecture. I tried to make the truth known, but the community wasn't interested.
*snip*
I've never required technical assistance from anyone. That may seem difficult to believe, and I tried to explain how I do it, but I was berated for about six pages for even mentioning it. Thanks for all the help. I came to resolve an issue regarding a product. I'm leaving with more than what I came with. I'll never forget this board and the members I met here.
@JohnnyBerg
I am most def. NOT trying to admonish you or your REF. I can't fault it's design. My comment was meat more towards HiGhVoltage. He seems to be ordering every ref he finds, w/o really getting the facts. So he is going to be disappointed, or at the lest not really have a basis for testing it when it arrives. That most certainly isn't the manufacturers fault.
Well, I am working on several projects for a client and I will need a good and stable reference and if I do not have to design it myself, I will save some time that I can use for other parts of the project. In this case I will test the reference myself and see if it will fulfill my requirements. It is low cost enough, that I do not worry, if it does not work perfectly.
I am thinking of making a second version, and perhaps I use a dip. I even consider putting the ref on a "island", to minimize the mechanical stress on the device.
When soldering the REF50xx chips, I put the boards on a pre-heater and slowly bring them up to 150c over the course of 30-45 minutes, then I apply a small heatsink to the chip itself and quickly drag solder each side at 265c with eutectic solder. Afterwards I ramp the pre-heater down to 85c over 15 minutes, then 50c over 15 minutes. Then I turn the heater off and leave the boards in place, so they're still receiving heat while the heater cools. I give it an hour or two to come back to ambient.
Overkill? Maybe. But I've got 8 of them going in a 25c chamber for the last 6 months gathering data, so I wanted to give them the best shot I could.
Next I want to put 10 REF5010's in series and make a 100 volt reference to classify.
Sent from my Smartphone
@JohnnyBerg
I am most def. NOT trying to admonish you or your REF. I can't fault it's design. My comment was meat more towards HiGhVoltage. He seems to be ordering every ref he finds, w/o really getting the facts. So he is going to be disappointed, or at the lest not really have a basis for testing it when it arrives. That most certainly isn't the manufacturers fault.
Well, I am working on several projects for a client and I will need a good and stable reference and if I do not have to design it myself, I will save some time that I can use for other parts of the project. In this case I will test the reference myself and see if it will fulfill my requirements. It is low cost enough, that I do not worry, if it does not work perfectly.
The problem is that it's virtually impossible to know if it's "working properly", without a baseline or point of reference to benchmark against.....one option is to grab a known "certified" transfer standard, and then cal 2 meters against it.....then it's easy to make less subjective determinations about random ebay or UN-doccumented "standards".....
@JohnnyBerg
I am most def. NOT trying to admonish you or your REF. I can't fault it's design. My comment was meat more towards HiGhVoltage. He seems to be ordering every ref he finds, w/o really getting the facts. So he is going to be disappointed, or at the lest not really have a basis for testing it when it arrives. That most certainly isn't the manufacturers fault.
Well, I am working on several projects for a client and I will need a good and stable reference and if I do not have to design it myself, I will save some time that I can use for other parts of the project. In this case I will test the reference myself and see if it will fulfill my requirements. It is low cost enough, that I do not worry, if it does not work perfectly.
The problem is that it's virtually impossible to know if it's "working properly", without a baseline or point of reference to benchmark against.....one option is to grab a known "certified" transfer standard, and then cal 2 meters against it.....then it's easy to make less subjective determinations about random ebay or UN-doccumented "standards".....I have a friend here in Germany not far from me, who has a full professional calibration lab.
I use his equipment to verify my SVR-T voltage standard.
huh? Just above you said "Well, I am working on several projects for a client and I will need a good and stable reference "
huh? Just above you said "Well, I am working on several projects for a client and I will need a good and stable reference "
Yes, this is the case.
May be it is not the most perfect solution, but so far it has worked for me.
In order to verify and confirm the voltage reference at my clients facility, I do the following:
1. Take my Geller Labs SVR-T (battery powered) to the professional calibration lab and get it verified.
2. Also take my Agilent 34410A to the same professional lab and get it calibrated.
3. Take both to the clients facility and get the 34410A warmed up.
4. Check the transfer of the SVR-T to be accurate to the 34410A
5. Verify the clients voltage reference with the 34410A.
6. If verified, give the client a paper of conformity based on these steps
Repeat this procedure every 6 month.
So far, my client has accepted this procedure and has also fulfilled his obligations to his customers.
It has closed-chassis calibration controls. That means you don't need to open the chassis to calibrate the unit.
And how do you do that exactly?
Please be precise in your detailed explanation.
Also, please explain by what mechanism removing the rear case causes damage to the circuitry or calibration.
Once again, please be precise.
When soldering the REF50xx chips, I put the .............
SNIP
When soldering the REF50xx chips, I put the .............
SNIP
Ref50xx is a bandgap device, what the point
It has closed-chassis calibration controls. That means you don't need to open the chassis to calibrate the unit.
And how do you do that exactly?
Please be precise in your detailed explanation.
Also, please explain by what mechanism removing the rear case causes damage to the circuitry or calibration.
Once again, please be precise.
Dave not sure why you need this detail. He is correct, you do not need to open it to calibrate it.
Calibration means comparison between measurements.
Clearly you can calibrate it without opening it
When there is a discussion about calibration with a non-technical person, it helps for simplicity sake to use phrase "Calibration-Verification" and "Calibration-adjustment" to differentiate.