DIY 7.5-digits DVM

iddqd2001 · 发表于 2014-6-28 21:38:01

ADC - ADS1282.
Voltage reference - 1N829 zener from Solartron 7081.
Input voltage +/- 16 V, impedance >10 GOhms, <1 ppm nonlinearity, <1 ppm/C temperature coefficient.

iddqd2001 · 发表于 2014-6-28 21:40:03

Test results:

DNL Fixed (EN).jpg

augusking · 发表于 2014-6-28 21:40:15

好手艺！

ysfc51 · 发表于 2014-6-28 21:53:37

相当不错

Aihe · 发表于 2014-6-28 21:58:04

赞一个

leglg · 发表于 2014-6-28 22:09:30

zsxlh · 发表于 2014-6-28 22:21:50

厉害！

菜鸟级玩家 · 发表于 2014-6-28 22:35:18

那位高人能把这个山寨了

zhikai_wu · 发表于 2014-6-28 22:41:25

实在是牛

张文松 · 发表于 2014-6-28 22:46:41

Well done...

jamesys · 发表于 2014-6-28 22:51:18

不错，

falcon_ljc · 发表于 2014-6-28 22:54:43

a magnificent DVM

aydali · 发表于 2014-6-28 22:57:51

:
用料奢华，制作惊艳，专业，霸气，让我这门外的爱好者膜拜。

python_k · 发表于 2014-6-28 23:00:40

输入阻抗怎么测的？

qqwintian · 发表于 2014-6-28 23:05:06

很棒，完成了我一直想试试的东西，有了前人的经验，我也好办多了

xuanmic · 发表于 2014-6-28 23:07:22

很厉害！好漂亮的作品！

aydali · 发表于 2014-6-28 23:09:59

：
不过也有些看得很迷惑，显示屏的排线是接在哪里呢？ADS1282周围管脚怎么和手册上对不上呢？别见笑。

iddqd2001 · 发表于 2014-6-29 00:04:11

DVM board and LCD display are connected to x86-compatible Mini-PC for debugging only.Input impedance was measured via 1 MOhm serial connection.

lilith · 发表于 2014-6-29 01:35:14

本帖最后由 lilith 于 2014-6-29 01:36 编辑

and...

I DIY a 7.5d Source-Meter used the Linear's ADC LTC2400 (Tested the Ti ADS 1232)：
https://bbs.38hot.net/forum.php?mod=viewthread&tid=82147

the Meter Input range +/- 12.5V，input impedance > 10^9 OHM。But the non - linearity error after fitting will still great

. The Temperature coefficient is very low but only because of my real-time aoto "Self-calibration" design both the hardware and software。

You saied your meter's Performance good that < 1 ppm nonlinearity and <1 ppm/C temperature coefficient, I hoped to see more Test data and the Test equipment should be more reliable。Or，zhe ADS1282 it's very high-performance than other ADCs？Even so, the input attenuation circuit（16V to 5V or 2.5V）' error is inevitable，How do you killed those problems？

iddqd2001 · 发表于 2014-6-29 01:54:17

Test equipment - Datron 4000A calibrator and two Solartron 7081 DMMs, modded to LTZ1000 voltage references.Input Amplifier is bootstrapped and have a metal-foil resistors divider and MAX44246 buffer. Schematics is similar to Datron 1281 DMM.

zhengdahe · 发表于 2014-6-29 02:00:00

厉害！

fmm · 发表于 2014-6-29 07:51:58

好牛，学都学不来呀。之前折腾了一个6.5的，发现效果一般，没有添加软件修正。

xinjihua · 发表于 2014-6-29 08:26:02

好牛，学都学不来呀

lizhijun · 发表于 2014-6-29 10:09:10

这个厉害，记号一下

lflyy · 发表于 2014-6-29 10:27:00

厉害！漂亮的作品！

jdgtx · 发表于 2014-6-29 10:28:41

都是高手哇，佩服。

marshallemon · 发表于 2014-6-29 10:51:43

记得不是之前一位老大说话ADS1282的en性能并不怎样，还没有24xx好？

人生感悟 · 发表于 2014-6-29 10:59:40

ahhui · 发表于 2014-6-29 11:32:51

It's awesome! Especially of the shields and all mechanical works, maybe use a VFD display will be more cool than LCD.

昇阳 · 发表于 2014-6-29 11:39:01

俺不会做们只能等楼主卖的时候。我买一个

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