Yihi SX350J Technology Discussion Thread

[retird]

Short copy of pulse fequency modulation vs. pulse width modulation.

The Advantages of Pulse Frequency Modulation for DC/DC Switching Voltage Converters | DigiKey

Just wondering Vlad1 if you saw any ripple with increased voltage... say 400 - 500F @ 30-50 joules? Or any voltage sag?

From link above...

Side effects of PFM operation

An increase in voltage output ripple is often observed when the switching converter flips to PFM mode because of the need for a tolerance band (rather than a fixed point) to sense when the power switches need to be turned on again. If a narrower tolerance band is used, the converter switches more frequently, which reduces the power saving. The engineer must decide on the best trade-off between improved low-load efficiency and increased voltage output ripple. Figures 2a and 2b illustrate the difference in voltage ripple for a switching converter operating in PWM and PFM modes, respectively.



During load transients, any switching converter will exhibit some amount of overshoot during a high-to-low-load transient or undershoot during a low-to-high-load transient. In the case of a converter that is operating in a PSM, the load level is already low, so the next transient will be from low-to-high current (which typically corresponds to transitioning from sleep to active mode). The increased load on the regulator output often results in “output-voltage sag” until the converter loop has time to respond.

Some switching converters include provision to minimize this voltage sag. TI’s TPS62400 employs “dynamic voltage positioning”. During PSM operation, the output-voltage set point is increased slightly (for example, by 1 percent) to anticipate the instantaneous voltage-sagging transient that occurs when the load is suddenly stepped higher. This prevents the output voltage from falling below its desired window of regulation during the initial load transient.

Some devices also offer an enhancement that can be used to balance the compromise between good transient response (best in PWM mode) and low power consumption (best in PSM). The enhancement is an intermediate mode that the engineer can implement using I²C commands to the converter IC that offers better transient response than PSM, but is more efficient than PWM. The intermediate mode is a good option for a system that goes from a high load to a very light load (for example, sleep mode).

Noted: PSM is Pulse Skipping Modulation...

 

[jazzvaper]

^^^^ This is what I intuited as "filtering". Frequency filtering.


Sent from my iPhone using Tapatalk

 

[Ariel_MX]

Yihi just posted this @ Facebook:

Yihi SX Mini @ Facebook

 

[Sptz]

They should definitely hire a translator... Geez

 

[dr g]

So. I'm not an SX expert by any means but these boards really strike me as OEM boards that are slightly modified for repurposing, as opposed to real modder boards. The size, the fixed screen location, the fixed USB, etc. are really unfriendly for modding. It's interesting to look over the componentry on the board too.

One quick thing I noticed is a filter cap on the fire button. Is this required? Does this imply the board does not have onboard filtering?

hmmmmmmmmm

 

[retird]

WE ARE BACK........nice at first glance.... ECF rocks.....

 

[tchavei]

WE ARE BACK........nice at first glance.... ECF rocks.....

Damm, they didn't lost you during the move










[emoji14] [emoji14] [emoji14]

Regards
Tony

Sent from my keyboard through my phone or something like that.

 

[retird]

Damm, they didn't lost you during the move










[emoji14] [emoji14] [emoji14]

Regards
Tony

Sent from my keyboard through my phone or something like that.

Yep.... still here.....new stuff to learn.... feel right at home since I figured out how to get my years old sig line back....

 

[tchavei]

Yep.... still here.....new stuff to learn.... feel right at home since I figured out how to get my years old sig line back....

I guess you can't choose family. We're deemed to be stuck to each other. [emoji14]

Did you have time to build your mod yet?

Regards
Tony

Sent from my keyboard through my phone or something like that.

 

[retird]

Nope.... with all the early talk about the hum/buzz/rattlesnake noise I cancelled the order...a buddy is testing one as we speak ..... gonna see how the bug fixes go and the updates....guess new stuff just comes with bugs....guess you saw Pbusardo's 2 part review...

 

[dr g]

So I've been putting an SXJ through the paces on a testbed, and of course ECF is down and phil's review comes up, and I can't say a word about it.

My first, and biggest point, is I really hope people can finally accept what I have been saying all along about joules now that the esteemed phil busardo has said the exact same thing. Joules are ... watts. The fact that the ramp curve can be programmed is irrelevant; the DNA-TPs showed that the watt setting can be a guideline. There is no real meaningful way joules are being applied in this application other than the total joules counter, now that is the real application of joules. I can't entirely be sure that joules were not selected as a setting to cover up deficiencies in the way this board operates.

Second, in my testing the temperature control of the SXJ is significantly less accurate and reliable than the DNA-TPs. The SXJ can blow right past the set temperature and stabilize at other settings, which are apparently more in line with its capabilities. It does not seem capable of throttling power as low as necessary for full temperature control. The DNA-TPs on the other hand will absolutely adhere to the temperature limit in any circumstance.

This may not be terribly surprising, as solid regulation in all situations has been an Evolv hallmark whereas Chinese boards often have ranges they work best in. However, ironically, this may have led to a perception that the DNA-TPs are less stable when in fact they are more stable and accurate.

Third, as expected, the manual setting of the baseline resistance is problematic. It is quite easy for that setting to be forgotten or mis-set, leading to a much higher chance of TP failure and a generally greater level of inaccuracy. I somehow doubt many people are making multiple checks on the atomizer to confirm absolute cooling. It's easy to take the automatic re-read and new atty checks on DNA boards for granted until it doesn't happen.

In general what I find is that it is quite possible that people who DON'T know much about TP or don't have a firm grasp on the technology may end up with the most favorable views of the SXJ. It is a flawed board with some outright engineering errors, likely owing to the fact that it was engineered to follow what another company was doing rather than from a standpoint of full understanding.

It is not surprising that this board was delayed so long before release, I'm willing to bet the first iterations of this TP system were disastrous. But at this point it has been tuned to the point that it is capable of producing a good vape in the range that most hobby vapers vape in. It's only when you really push the TP do the flaws become apparent.

Subjectively, having not used previous SX boards, I was struck by the complexity and user-unfriendliness of the UI on the SXJ. It is one fiddly board and TP only complicates that. As a longtime Evolv user the difference was stark and very frustrating.

Oh for the record, I did not hear a hum on my unit, but I did find the rattlesnake very early on and I was surprised I had not heard about it before from other testers.

 

[tchavei]

So I've been putting an SXJ through the paces on a testbed, and of course ECF is down and phil's review comes up, and I can't say a word about it.

My first, and biggest point, is I really hope people can finally accept what I have been saying all along about joules now that the esteemed phil busardo has said the exact same thing. Joules are ... watts. The fact that the ramp curve can be programmed is irrelevant; the DNA-TPs showed that the watt setting can be a guideline. There is no real meaningful way joules are being applied in this application other than the total joules counter, now that is the real application of joules. I can't entirely be sure that joules were not selected as a setting to cover up deficiencies in the way this board operates.

Second, in my testing the temperature control of the SXJ is significantly less accurate and reliable than the DNA-TPs. The SXJ can blow right past the set temperature and stabilize at other settings, which are apparently more in line with its capabilities. It does not seem capable of throttling power as low as necessary for full temperature control. The DNA-TPs on the other hand will absolutely adhere to the temperature limit in any circumstance.

This may not be terribly surprising, as solid regulation in all situations has been an Evolv hallmark whereas Chinese boards often have ranges they work best in. However, ironically, this may have led to a perception that the DNA-TPs are less stable when in fact they are more stable and accurate.

Third, as expected, the manual setting of the baseline resistance is problematic. It is quite easy for that setting to be forgotten or mis-set, leading to a much higher chance of TP failure and a generally greater level of inaccuracy. I somehow doubt many people are making multiple checks on the atomizer to confirm absolute cooling. It's easy to take the automatic re-read and new atty checks on DNA boards for granted until it doesn't happen.

In general what I find is that it is quite possible that people who DON'T know much about TP or don't have a firm grasp on the technology may end up with the most favorable views of the SXJ. It is a flawed board with some outright engineering errors, likely owing to the fact that it was engineered to follow what another company was doing rather than from a standpoint of full understanding.

It is not surprising that this board was delayed so long before release, I'm willing to bet the first iterations of this TP system were disastrous. But at this point it has been tuned to the point that is is capable of producing a good vape in the range that most hobby vapers vape in. It's only when you really push the TP do the flaws become apparent.

Subjectively, having not used previous SX boards, I was struck by the complexity and user-unfriendliness of the UI on the SXJ. It is one fiddly board and TP only complicates that. As a longtime Evolv user the difference was stark and very frustrating.

Oh for the record, I did not hear a hum on my unit, but I did find the rattlesnake very early on and I was surprised I had not heard about it before from other testers.

And yet, in the end, people are loving the sx mini m despite all flaws you seem to have found.

Anyway, I think it would be fair to people reading this knowing your affiliation to Evolv. You know, it's like a Volkswagen seller reviewing a BMW. He might be right about what he sais but... You know what I mean


Ps: we were really worried about you when the busardo review came out and ECF was down. Glad you're alright and kicking.

Regards
Tony

Sent from my keyboard through my phone or something like that.

 

[dr g]

Actually his review was a good deal less unfair than I expected. While he repeats some of the socially pressured thought errors of the previous review, he did objectively report many of the flaws of the board and confirmed much of what I've been saying all along about it.

I think he got the comparison at 280f wrong though, no one I know of is successfully running KF4s and squapes on DNAs at 280f. To me it seemed like he put a warm atty on the device and ended up jacking the temps (selected new atty).

 

[jhawk]

Actually his review was a good deal less unfair than I expected. While he repeats some of the socially pressured thought errors of the previous review, he did objectively report many of the flaws of the board and confirmed much of what I've been saying all along about it.

I think he got the comparison at 280f wrong though, no one I know of is successfully running KF4s and squapes on DNAs at 280f. To me it seemed like he put a warm atty on the device and ended up jacking the temps (selected new atty).

Totally agree. Mine is never out more than 10F when pulsing at 400 or whatever, and never over.

 

[peraspera]

Second, in my testing the temperature control of the SXJ is significantly less accurate and reliable than the DNA-TPs. The SXJ can blow right past the set temperature and stabilize at other settings, which are apparently more in line with its capabilities. It does not seem capable of throttling power as low as necessary for full temperature control. The DNA-TPs on the other hand will absolutely adhere to the temperature limit in any circumstance.

Could you please provide some details for the girl wearing the dunce cap in the corner of the electronics/physics class? What I taste in temperature is in no way reflected in what I see the screen is showing as temperature. I'm thoroughly confused about what I have been experiencing with my SX Mini and why.

The temperature I perceive as I am actually vaping seems warmer than the set temperature when there is a lot of juice on the coil but seems lower as the wick dries out but the screen only shows single digit fluctuations at most. It does this with the Subtank Mini, Tilemahos, Magma and Marquis using .06–1.2 oHm builds running at between 13–25 watts. However, the rDNA 40's temperature/power level display seems to rise and fall much more in line with temperatures I perceive when vaping using the same RTAs and RDAs with the same set temperature/power levels for the SX Mini and rDNA40.

 

[Vlad1]

So I've been putting an SXJ through the paces on a testbed, and of course ECF is down and phil's review comes up, and I can't say a word about it.

My first, and biggest point, is I really hope people can finally accept what I have been saying all along about joules now that the esteemed phil busardo has said the exact same thing. Joules are ... watts. The fact that the ramp curve can be programmed is irrelevant; the DNA-TPs showed that the watt setting can be a guideline. There is no real meaningful way joules are being applied in this application other than the total joules counter, now that is the real application of joules. I can't entirely be sure that joules were not selected as a setting to cover up deficiencies in the way this board operates.

Second, in my testing the temperature control of the SXJ is significantly less accurate and reliable than the DNA-TPs. The SXJ can blow right past the set temperature and stabilize at other settings, which are apparently more in line with its capabilities. It does not seem capable of throttling power as low as necessary for full temperature control. The DNA-TPs on the other hand will absolutely adhere to the temperature limit in any circumstance.

This may not be terribly surprising, as solid regulation in all situations has been an Evolv hallmark whereas Chinese boards often have ranges they work best in. However, ironically, this may have led to a perception that the DNA-TPs are less stable when in fact they are more stable and accurate.

Third, as expected, the manual setting of the baseline resistance is problematic. It is quite easy for that setting to be forgotten or mis-set, leading to a much higher chance of TP failure and a generally greater level of inaccuracy. I somehow doubt many people are making multiple checks on the atomizer to confirm absolute cooling. It's easy to take the automatic re-read and new atty checks on DNA boards for granted until it doesn't happen.

In general what I find is that it is quite possible that people who DON'T know much about TP or don't have a firm grasp on the technology may end up with the most favorable views of the SXJ. It is a flawed board with some outright engineering errors, likely owing to the fact that it was engineered to follow what another company was doing rather than from a standpoint of full understanding.

It is not surprising that this board was delayed so long before release, I'm willing to bet the first iterations of this TP system were disastrous. But at this point it has been tuned to the point that it is capable of producing a good vape in the range that most hobby vapers vape in. It's only when you really push the TP do the flaws become apparent.

Subjectively, having not used previous SX boards, I was struck by the complexity and user-unfriendliness of the UI on the SXJ. It is one fiddly board and TP only complicates that. As a longtime Evolv user the difference was stark and very frustrating.

Oh for the record, I did not hear a hum on my unit, but I did find the rattlesnake very early on and I was surprised I had not heard about it before from other testers.

Would love to see your test results when you get them completed. Please upload and share so we can all see what you've been able to acquire. Also what are you using for your testbed and measuring devices?

 

[jhawk]

The joule (pronounced DJOOL) is the standard unit of energy in electronics and general scientific applications. One joule is defined as the amount of energy exerted when a force of one newton is applied over a displacement of one meter. One joule is the equivalent of one watt of power radiated or dissipated for one second.

In some applications, the British thermal unit (Btu) is used to express energy. One Btu is equivalent to approximately 1055 joules.

When you cut on a 100 watt light bulb it instanlty burns at 100w, A joule reminds me of those old time light bulbs with 3 clicks to get the brightness up.

Simple free your mind your ... will follow.

 

[dr g]

Could you please provide some details for the girl wearing the dunce cap in the corner of the electronics/physics class? What I taste in temperature is in no way reflected in what I see the screen is showing as temperature. I'm thoroughly confused about what I have been experiencing with my SX Mini and why.

The temperature I perceive as I am actually vaping seems warmer than the set temperature when there is a lot of juice on the coil but seems lower as the wick dries out but the screen only shows single digit fluctuations at most. It does this with the Subtank Mini, Tilemahos, Magma and Marquis using .06–1.2 oHm builds running at between 13–25 watts. However, the rDNA 40's temperature/power level display seems to rise and fall much more in line with temperatures I perceive when vaping using the same RTAs and RDAs with the same set temperature/power levels for the SX Mini and rDNA40.

I don't really have a good answer for this other than that the SXJ may be fudging the results a bit. I do notice that the operation seems to skew high (temperature skews low) in real world applcation.

It is always hard to talk temperature specifics with the SXJ because of the inherent inconsistency of the calibration method.

 

[JimScotty0]

Third, as expected, the manual setting of the baseline resistance is problematic. It is quite easy for that setting to be forgotten or mis-set, leading to a much higher chance of TP failure and a generally greater level of inaccuracy. I somehow doubt many people are making multiple checks on the atomizer to confirm absolute cooling. It's easy to take the automatic re-read and new atty checks on DNA boards for granted until it doesn't happen.

It has been 3 weeks now that I have been using the M class and I am very conscious of setting the baseline resistance when the device has stabilized temperature. Usually about 15 mins. I do routinely check it to see if there is a change whenever I have it rested for a while. They are spot on with little change if any at all. I am finding this even after changing out atty's.

An analogy might be... There are some people that are not suitable to run a car with a manual transmission and I have personally met many that meet that classification. Then there are some that take to the gear shift and pull the most performance and timing to make that connection with the engine just work like magic. When you see that in action it is a work of art! If you are the type that can't remember to set your baseline, or your builds are a bit shaky, then the SX Mini M Class is not for you. The SX M Class is an APV and was not designed to be used by those who like the automatic mode of vaping. Since I am not a DNA owner, I really can't speak directly for those who use it, but from your description it sounds like it is meant more for those who are more suited for the automatic mode but still wanting to use an APV device anyway. I think any serious vaper that is not in the hobby vaping class would find the Yihi M class a great mod.

For the record, I always prefer to buy American products rather than a Chinese product whenever possible even if it means paying more for it. I am not the consumer type that buys cheap but instead I usually buy high quality products in all aspects of my life and usually after doing quite a bit of research. I actually believe I have some OCD in that area. With that being said, I have been closely following the TC mods, reviews, and forums since they first started including the Busardo videos with Evolv. I wanted to buy Evolv and cost was not an issue to me but I didn't feel it was ready. With the Yihi SX 350J chip and the SX Mini M Class I made a conscious decision to buy it despite it being Chinese and not an American product. It was because of the quality I bought it and the research I did prior to the purchase. It was in my opinion the best thing out there and I wanted to get into TC. I knew it would not be perfect as I believe engineering is in the infancy stage with TC, but it was big step forward and I was ready to take that TC plunge finally.

All I can say is that I am extremely happy with my Yihi SX Mini M Class mod, and would buy it again in a heartbeat. It isn't perfect but it is a great device and gives a great vaping experience. The USB firmware upgrade capability will make this an even greater device as we see future upgrades from Yihi. Not many other APV mods can do that so you are stuck with what you bought and frozen in time.

 

[dr g]

Actually the SXJ deals with shaky builds somewhat better than the DNA, it is far less ... demanding in what it does. I honestly dont think this is by design, i think it's a byproduct of its less-than-accurate operation.

The transmission analogy doesn't hold up. With a manual transmission there is a meaningful amount of control over gear selection and powertrain engagement and disengagement. With the manual calibration there is no such meaningful control, all it is is an inconvenience and a place where inaccuracy and errors are introduced.

I'm trying to think of a good analogy but coming up blank right now. I was thinking like, black powder vs cartridges, but eh. Not great.

The calibration method of the SXJ is IMO a design error. It actually smacks of afterthought or bodge. I wouldn't doubt that yihi's first attempts at tc resembled the smok m80. there is still a hint of familiarity between the two experiences.