JOY7307 Multi-Calibrator with 7.5digit DCV, 6.5digit DCI and standard Ohm output - Page 1
Forum section: electronics / testgear

author: Edward3121
author_rank: Contributor
timestamp: June 22, 2021, 02:58:58 pm
content: A simple demo video:https://youtu.be/vVtmyE5ElQUFeatures:<>Use LTZ1000ACH as voltage reference.<>Use VHD200 for 7V to 10V conversion.<>7.5Digit DC Voltage resolution, INLmin<1ppm, TCmin<0.3ppm.<>6.5Digit DC Current resolution, INLmin<2ppm, TCmin<3ppm.<>9 physical resistors Ohm Output with 4-wire.<>Low noise 1.5uVp-p@10Hz typical.<>Additional DC voltage measurement function.<>Fully digital calibration.<>Small size (140x100x83mm), battery powered, suitable for portable use.Introduction:JOY7307 is a new works of selena2211 ( Chinese nickname: 乐逍遥) (NOT me). JOY7307 is a multifunction calibrator powered by a lithium battery, suitable for portable use. JOY7307 uses LTZ1000ACH as the voltage reference and VHD200 as the 7V to 10V conversion resistor to achieve ultra-low temperature drift, high stability and low noise. The DC Voltage resolution is 7.5 digit, the lowest adjustable value is 0.1ppm.Functions:<>DCV OUTPUT:#10V Range: -10uV~11V adjustable, 7.5Digit, INLmin<1ppm, TCmin<0.3ppm#1V Range: 0uV~1.1V adjustable, 7.5Digit, INLmin<1ppm, TCmin<1ppm<>DCI OUTPUT:#100mA Range: 0~110mA adjustable, 6.5Digit, INLmin<2ppm, TCmin<5ppm#1mA Range: 0~1.1mA adjustable, 6.5Digit, INLmin<2ppm, TCmin<3ppm<>Ω OUTPUT:#ΩRange using 9 physical resistor, they are 0Ω, 10Ω, 100Ω, 1kΩ, 10kΩ, 100kΩ, 1MΩ, 10MΩ and 100MΩ. The performance of Ω range is related to the actual resistor used, and the calibration value is 7.5 digits.<>MEAS:#DC Volt meter, 12.5V range, 7.5Digit, INLmin<1ppm, filter is enabled by default<>OTHERS:#Clock & internal temperature#LCD contrast adjustment#LCD backlight ON/OFF#Keypad tone ON/OFFHere are some images, more images and videos will upload later.

author: Edward3121
author_rank: Contributor
timestamp: June 22, 2021, 03:05:09 pm
content: the noise

author: baof
author_rank: Newbie
timestamp: June 22, 2021, 03:11:23 pm
content: Cool ！！！

author: HighVoltage
author_rank: Super Contributor
timestamp: June 22, 2021, 06:23:45 pm
content: Nice!Are you planning to make this commercially available ?

author: thm_w
author_rank: Super Contributor
timestamp: June 22, 2021, 09:00:43 pm
content: Quote from: HighVoltage on June 22, 2021, 06:23:45 pm"JOY7307 is a new works of selena2211 ( Chinese nickname: 乐逍遥) (NOT me). ""His chinese nickname is 乐逍遥, and english nickname is selena2211. And some othe works, such as AC Noise AMP, Low EMF Scanner, Chiron 7120A Series(LTZ1000/LM399*4), Mini 10V Ref(LTZ1000), Standard Resistance Box are also available."

author: syau
author_rank: Frequent Contributor
timestamp: June 22, 2021, 11:16:43 pm
content: QuoteDid he sell under toabao or aliexpress ?

author: AVGresponding
author_rank: Super Contributor
timestamp: June 22, 2021, 11:22:26 pm
content: The date codes on some of the components are quite curious. NOS? Salvaged?

author: coromonadalix
author_rank: Super Contributor
timestamp: June 22, 2021, 11:37:56 pm
content: Why is it so hard to do a proper board clean up after soldering ...

author: Edward3121
author_rank: Contributor
timestamp: June 23, 2021, 01:20:51 am
content: Quote from: HighVoltage on June 22, 2021, 06:23:45 pmIt has already been commercialized in China. But, to other countries, shipping my be a tricky problem. And he is looking for a solution.

author: Edward3121
author_rank: Contributor
timestamp: June 23, 2021, 01:21:55 am
content: Quote from: AVGresponding on June 22, 2021, 11:22:26 pmFor cost reasons, some components use disassembled components. Even so, its price still exceeds many people's expectations. For example, the price of a disassembled relay only costs about US$2, but the brand new price is more than US$8. There are many such relays in JOY7307. He will carefully test these disassembled components before use to eliminate defective components.In fact, JOY7307 focuses on low prices. After all, compared with DMM, the price of the calibration source is much more expensive, and many people can only stay away from it.At the same time, JOY7307 is a customized product, and customers can propose to increase or decrease the configuration according to their own needs, or even use completely new components.In fact, my JOY7307 is a reduced version, the one in the demo video.考虑到成本原因，一些元件使用了拆机元件。即便如此，它的价格仍然超出了很多人的预期价格。举个例子，一个拆机继电器价格只需要2美元左右，但是全新价格超过8美元，JOY7307里面使用了很多这样的继电器。他会在使用之前，仔细测试这些拆机元件，以淘汰不良元件。事实上，JOY7307主打的就是低价格，毕竟与DMM相比，校准源的价格要贵很多，很多人只能望而却步。同时，JOY7307是一个定制产品，客户可以根据自身需求提出增配、减配，甚至全部使用全新元件。事实上，我的JOY7307就是一个减配版本，就是演示视频里的那个。

author: Edward3121
author_rank: Contributor
timestamp: June 23, 2021, 01:37:52 am
content: Quote from: syau on June 22, 2021, 11:16:43 pmHe has a shop on Taobao, but mainly sells in the QQ group.他淘宝上有个店铺，但是基本上不在淘宝上卖东西了，主要在QQ群里交流。Taobao:https://shop58205423.taobao.com/?spm=a230r.7195193.1997079397.2.b6ae3c99kZFSny

author: MegaVolt
author_rank: Frequent Contributor
timestamp: June 23, 2021, 08:39:37 am
content: https://www.eevblog.com/forum/buysellwanted/lfs-joy-7307-multifunction-calibrator/

author: ass20
author_rank: Regular Contributor
timestamp: February 02, 2023, 05:18:04 am
content: HiEdward3121I very interesring to another selena2211 project Joy6.5DMMI found shematics and photo on mydigit forum and download itBut firmware is not work goodCan you said, where i can found selena2211 ?

author: Edward3121
author_rank: Contributor
timestamp: February 02, 2023, 05:52:09 am
content: Quote from: ass20 on February 02, 2023, 05:18:04 amHi~Can you use QQ or WeChat?Now we discuss this in QQ groups and WeChat groups.QQ group No. is 384456070.Wechat group, you can send me a message and I replay a QR code, use Wechat scan the QR code to join.Also, you can find him onhttp://bbs.38hot.net/index.php,but this old forum may have some problem with registration.Sch and firmware I think you found is "Handheld 6.5" ,not the lasteset JOY6.5. And we have the lastest firmware of "Handheld 6.5" in QQ group.

author: ass20
author_rank: Regular Contributor
timestamp: February 02, 2023, 08:22:11 am
content: i do not have QQQQ registration blocked from outside of chinaI have weChat only

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: February 02, 2023, 08:26:47 am
content: Nice project, I suggest you share the project files on github,so many people can contribute to it.

author: coromonadalix
author_rank: Super Contributor
timestamp: February 02, 2023, 05:45:37 pm
content: have you seen some prices on the web ........ outch