Aixun T3A overshooting?

[stj]

Re: Aixun T3A overshooting?

i didnt know it buzzed?

[tony359]

Re: Aixun T3A overshooting?

Yes, of course it depends on the duty cycle. There is a power indication on the display, it goes up to 87% which of course it doesn't mean it's delivering constant 170W but the duty cycle is adjusted so it's 87% of the max power... you know what I mean

ahah, we reverse engineered the reverse engineered one

One thing I might have noticed with 1.33 is that the station is noisier? It's buzzing louder.

[stj]

Re: Aixun T3A overshooting?

in regard to your comment about 170w boost,
soldering stations use PWM driven mosfets.
it's either 170w or nothing - it's the duration that counts

there is a project to reverse engineer the T3A, they have extracted the firmware and i think created a schematic.
maybe they will eventually customise the firmware
https://github.com/c0d3z3r0/aixun_t3a_rev

[tony359]

Re: Aixun T3A overshooting?

Turned out the issue was already mentioned on EEVBlog forum and indeed downgrading to 1.33 fixed it.

Too bad for Axiun who replied with Marketing BS to my query. But hey...

[tony359]

Re: Aixun T3A overshooting?

ah gotcha. Then I guess it's kind of understandable even though I still don't understand why the unit is letting the tip cool down to a point where it deserves a 170W boost
The tip does not cool down instantly so in theory the algorithm has plenty of time to realise it needs to push the power a tad more. Uhm...

Someone on my video recommended to downgrade to 1.33

[stj]

Re: Aixun T3A overshooting?

no, it doesnt know what cartridge it is.
in theory if you had a menu to tell it the cartridge model it could compensate by having a lookup table.
one of the cheaper units - maybe quicko or ksger has a tip menu that lets you set different offsets for the temp, so it's possible

there is a very expensive station that does have an eeprom in the cartridge but thats going to be stupid money.
i think it may be hakko or weller but not sure - it's not been cloned anyway.

[tony359]

Re: Aixun T3A overshooting?

well... you can see the temperature is creeping down for no apparent reason. I see what you mean and I don't disagree but I feel there is some improvement possible in keeping a more stable temperature when the tip is not doing anything.

The software should push a tiny little more power in the tip to avoid the temp going below the threshold which likely triggers the "temp has lowered, they must be soldering, let's pump 200W to the tip to compensate".

Does the station know what type of tip is being connected? I remember watching some reviews (not sure about what station) where it was being mentioned that the reason why the full 100% power was not being sent to a specific tip was because it was too small to take that amount of power.

Indeed a "high thermal efficiency" tip would require more power than a very small, tiny precision soldering one.

[stj]

Re: Aixun T3A overshooting?

to be fair then, it's probably the tip mass causing a delay between the sensor and heating element thats hard to predict in software.

[tony359]

Re: Aixun T3A overshooting?

Aixun replied to my enquiry saying it's intentional (of course!).

It might make sense though: they say it's designed to give the tip a little boost when the solder is being melt, to prevent the tip from dropping the temperature too much.

I admit that when measuring on a thermometer there is no mass, hence the test is kind of "unfair". On a proper solder joint I'd imagine the overshoot is not as bad.

Still, with the smaller knife tip that does not happen so... uhm...

[tony359]

Re: Aixun T3A overshooting?

it is, you can see 1.34 on the display.

It does look like a software issue to me. I've reported it to Aixun, also mentioning I am reviewing it, it might get some traction

The funny thing is that a couple of versions before it said "fixed overshoot on 245"
Maybe I should try downgrading!

[stj]

Re: Aixun T3A overshooting?

maybe software - is it the lastest version?
https://aixun-updates.github.io/

[tony359]

Hi all,

I've just purchased an Aixun T3A T245 soldering station and I am pretty happy with it, coming from a Hakko knockoff.

However, I purchased a genuine JBC tip and the temp massively overshoots with it. I can see a similar behaviour with the Aixun tips but not so horrible.

With the JBC tip on the thermometer I see the temp more or less stable but slowly dropping. At some point there is a 100% power spike and the registered temp goes +40C from where it was - obviously the display doesn't show anything!

Is this "expected"? 40C seems quite a lot.

See a video of what's happening here: https://youtu.be/z6oj99W5PH0

I am just holding the tip on the thermometer, no wet sponges or anything.