Yihua 305D IV off measurements

[marce002]

Hi

I was wrong buying this bench YIHUA 305D IV!!! is was a real mistake since amps readings are terrrible off... Can anyone know how can I calibrate with the 4 internal blue pots in order to have real amps reading and not offset in low currents (like 100mah error!!...)

I have managed to get volts almost acceptable *compared with my reliable unit multimeter 980d+, but current think has 3 pots to work with.... i know maybe they are for:

1- mA range gain.
2- A range gain.
3- mA and A offset.
4- V gain. says VR in the board attached pic


but dont know which one controls what, in the IV version... see circuit attched

also the procedure to calibrate or adjust..... low current measure half of the real current eg says 50mah and should be 110mah in 4000mah says 310mah and so
crap

[clearchris]

Re: Yihua 305D IV off measurements

They do have contact information, why don't you ask?

http://yihua-soldering.com/product-4...ply-en/160008/

I wouldn't imagine they would be proprietary about that. I assume there was no manual?

[marce002]

Re: Yihua 305D IV off measurements

Already contacted them... is a shame support gave nothing useful

[budm]

Re: Yihua 305D IV off measurements

So you have calibrated Amp meter as a reference (980d+???) to verify that the meter of the power supply is not correct?
"low current measure half of the real current eg says 50mah and should be 110mah in 4000mah says 310mah and so"
So in low range the error is more than 100% off, showing 50mA instead of 110mA, But what does "in 4000mah says 310mah" mean? The real current is 4000mA but the power supply meter shows only 310mA?
The IV version may be too new to have some review and info about the problem for this IV version.


https://yihuadz.en.made-in-china.com...er-Supply.html
I like their claim of 'high precision'. Link in post #2 does not show the IV model.

https://cdn.badcaps-static.com/pdfs/...9b15493ec5.pdf
Not much in the manual. So far I have not found schematic for the unit to show what the pots are for.

There are some info at EEVBLOG for the 305d, the circuit mat be the same and only the displays are not the same.
https://www.eevblog.com/forum/review...05d-bench-psu/
https://www.eevblog.com/forum/review...ion-procedure/

Some youtube for 305D: may be the same quality for the IV series.
https://www.youtube.com/watch?v=KEppGK6wWKA

[marce002]

Re: Yihua 305D IV off measurements

Budm sorry 3100mah and my tester is a 890d+ i was in a hurry typing