When the cartridge was connected mid-air, there was no noise
but when I used the handle, the handle was buzzing.
Me neither. Since both the SMPS and handle are buzzing I really think it's the pwm swichting of the controller...
...
Oh well, it depends very much on the temperature set (how much it needs to heat). Set it to 380 or 400 degrees and you'll hear that buzzing each 1-2 seconds.
Yes for the opening of these handles - it can be done non-destructively, with some care taken. And perhaps you can see inside what few is in there to go wrong. (If not a poor ground pin contact, but in general tolerances between the rings and the contacts can be less well fitting to make some clean and strong connection).When the cartridge was connected mid-air, there was no noise
Could you please try to clarify what you are actually saying here?
Are you saying by "cartridge mid air" that you put clips onto a bare T245 cartrigage (not in any handle whatsoever). And then ran yourself custom wires to the base unit, to test the cartidge alon outside of the handle?
Or are you saying that you took a C245 cartridge in 1 hand, and then the Aixun T245 handle in the other hand, and plugged it in while the handle was removed from the stand, that then it buzzed?but when I used the handle, the handle was buzzing.
Ok. So again, I am not fully clear. Are you saying that "handle is cradle", that when you leave the handle into the cradle stand. That then it buzzes?
Because this could be that when the ground jacket of the cartridge is inserted into the stand. That it then has a poor electrical connectivity through the metal stand itself. That then is supposed to go through that banana wire, which is a return path back to the station's sense pin (stand detect pin).
This could then be like something to give a partial circuit, for example if not plugged into. Or if through the MCU isn't clear path to ground.
I am scratching my head here. But when I measure this stand detect pin on my PCB, it's not connected to ground, it's like mega ohms (or not connected to GND path). However you can see on the PCB that they used a green and yellow ground wire to run as a seperate cable to the back of the station, the 4mm banana jack to the stand detect port. That has it's own dedicated wire.
So if you re-assembled your station back together, and mistook this ground marked wire for ground (that it is not actually). Then perhaps some mis-wiring or something can be possible by error? But then the stand detect function cannot work, that the heater cannot heat up. And it seems like an easy to spot mistake. (To eliminate at least).
Me neither. Since both the SMPS and handle are buzzing I really think it's the pwm swichting of the controller...
...
Oh well, it depends very much on the temperature set (how much it needs to heat). Set it to 380 or 400 degrees and you'll hear that buzzing each 1-2 seconds.
This c0d3z3r0 makes more sense probably to explain buzzings. That the PWM is not clean itself. But either double PWM, or that the switching mosfet is kindda failed, damaged or otherwise out of spec? For example, if the mosfet is replaced to a perfect mosfet. Then can the buzzing be eliminated?
In other words, does the ambient conditions affect / impart noise onto the sensitive mosfet gate? (To then mess up the switching).
With this cap installed, suddenly I witnessed the weird bug that Tony shared not too long ago. The screen would turn off, complaining about "no tool installed" and then quickly coming back alive a second later showing a readout of the temperature, and then go off again half a second after. This is getting more and more confusing as I go down this rabbit hole. Why would this happen?
When the cartridge was connected mid-air, there was no noise
Could you please try to clarify what you are actually saying here?
Are you saying by "cartridge mid air" that you put clips onto a bare T245 cartrigage (not in any handle whatsoever). And then ran yourself custom wires to the base unit, to test the cartidge alon outside of the handle?
Are you saying that "handle is cradle", that when you leave the handle into the cradle stand.
I just had the idea I could set up very simply circuit with Arduino, MOSFET, tip and do some experiments with PWM and see if I can reproduce this behaviour with different timings/duty cycles/whatever... Maybe later..
Put a good 10R or so in series with the cap. You've most likely made a VHF/UHF oscillator.
and he already said that without handle not buzzing...
anyhow moving on, i have to say also: the fact that the tip is hard grounded is... indeed not ideal design choice. wouldn't it be better thru a resistor? (for example 1mohm is typical for esd grounding, otherwise some other suited values). what would be good is if then the thermocouple can be working and giving valid readings with that esd resistor in place. not to throw it off.
To T12 clones I add a fast diode like RS1M across the heating element to clamp -ve spikes. I have also seen a small cap across the heater to help with that. Would also add to a T3.
Laptop power MOSFET AO4413 max. VGS +/-25V and VDS -30V. With those R6 10k, R11 1k resistors gives drive of 21.8V and T12 clones instead use 2k (or 4k7)/1k for 16V or 20V drive.
anyhow moving on, i have to say also: the fact that the tip is hard grounded is... indeed not ideal design choice. wouldn't it be better thru a resistor? (for example 1mohm is typical for esd grounding, otherwise some other suited values). what would be good is if then the thermocouple can be working and giving valid readings with that esd resistor in place. not to throw it off.
I have not been able to find a clear answer on that. There are various people saying direct earth is better while others say a 1 Meg resistor is better... Anyway, it's unclear if that resistor would influence tc measurements
Nice, but did this also solve the controller board and smps buzzing?
Just done on mine. No tape inside the handle here.
Difficult to open it, need to glue it after the intervention.
No more noise frome the handle.