Aliexpress Yunbao pulse skipping Product Guide manual

[black.yang]

Hello, everyone.
Recently, many friends mail to me to find to Yunbao driver's manual.
Yunbao was originally designed by me and later shared its code with some Chinese form enthusiasts.
So project was fork and made it a cheap driver for hobbyists.
I got a product user manual from the fork designer，
Unfortunately, at this version it is described in Chinese.
Fortunately, the ports in the picture are described in English, you may need to use Google Translate to help you understand more detail.
But it's better than nothing. 
enjoy it！

[black.yang]

https://highvoltageforum.net/index.php?topic=506.0
Answer questions in this post and my email 

[Weston]

So this controller regulates the average tank current by skipping pulses? Is this for QCW operation?

Do you have any photos or waveforms of the controller in operation? In the past, people have talked about using a pulse skipping controller for QCW coils but the consensus was that loaded Q is too low to effectively regulate the tank current.

I see a crystal oscillator on the board, are you using the FPGA to control the phase lag digitally to get more accurate zero voltage switching?

[black.yang]

You can see what you want from this page.
https://4hv.org/e107_plugins/forum/forum_viewtopic.php?p=1&id=179388#post-179400
In fact, there is only one GDT in the original design. In order to ensure magnetic balance, when the current over the threshold, a resonance period width will be skipped on the GDT. So it is more suitable to call it "skipping cycle".
A ramp signal input port is reserved on the circuit board. It has been tested that it can be used to operate QCW mode, but the test effect is mediocre and the arc does not look straight.

[maxhi]

Hello,
thank you very much for this manual. It is very helpful.
You can get these boards very cheap but I got no information about it.
Does somebody know, what the P4 connectors  (number 9 in the photo) are for?
Thanks

[L_Mangold]

Bless your heart, I just bought one of these. I’ll try to post results in a few weeks

[octopus1]

I know this is stupid but I can’t seem to find the output voltage on a data sheet. Does anyone know we’re I can find this?

[Maju]

Hi,

The output voltage equals the input voltage minus the voltage drops across the input rectifier bridge.

In other words, this driver does not have a voltage stabilizer for GDT outputs power supplying. The output voltage is directly dependent on the supply voltage. This has its advantages and disadvantages 

[octopus1]

So if I would want to driver a bridge that needed 24v I would use 24v plus the voltage drop through the rectifier as my input voltage?

[Maju]

So if I would want to driver a bridge that needed 24v I would use 24v plus the voltage drop through the rectifier as my input voltage?

Yes, exactly.

The easiest way to do this is to supply this driver with 18V AC. It will give you ~ 24V DC.
If you are using a 24V DC power supply, solder in after the rectifier bridge or get rid of it to avoid voltage drops.

But!...

Note that the smoothing capacitors at the power input (2x big 4700uF electrolytes) are only rated for 25V max. So you only have 1V in reserve. I love reducing costs used by manufacturers... 

So ask yourself if you really need 24V. If so, be sure to replace these two capacitors with others with a higher operating voltage.

For example, I supply this driver with 16V AC, which gives me just over 21V DC at the output. This voltage is fine if you have large transistors and are not pushing them to the limit.

[octopus1]

Oh okay that makes sense, I’ll definitely do a lower power than 24v then, wouldn’t want to blow those capacitors! I have one last question about the fiber connector, it looks like it uses toslink, can this be replaced with another type? And does it operate like normal toslink or is it a regular on=high off=low?

[Maju]

There are an interesting things about fiber optic receiver. It seems that the board has holes for the widely used HFBR receiver. I haven't tested it but the place is where toslink is mounted. Of course there is another "but" 

This driver needs a special signal to work properly. It is not simple 0 and 1.
Probably to minimize the interference to which the toslink is very sensitive, a carrier wave with a frequency of 1MHz was used. In other words, the driver needs a 1MHz signal to interpret it as high (special interupter included).

These rules apply to the TOSLINK receiver, I have no idea what would happen if it was replaced with a "standard" one, maybe the signal from it has no such restrictions and works as a standard 0 or 1, but I haven't tested it.

[panjaksli]

I think the fpga itself is programmed to that 1mhz signal,
Since stupid me soldered a capacitor to filter the weird looking output wave on the transmitter and then measured, that signal is perfect square wave on the driver itself, when received, but no response occurred.
My point is, the other connector is pin-pin interconnected with the other one and fpga doesn't respond to anything other than 1mhz signal, so yes the connector would work, but you would have to transmit the high frequency wave anyways.

[GrantV]

Hi there,

I am having a problem when testing my yunbao driver.

The pulse width (on time) is working properly but at minimum frequency (bps) I am seeing just 800uS between bursts, which is 1.25KHz.



Can you help?

[JCF]

Hello GrantV,
what test on bench ?
take care with SKP and DR interruptor.

[GrantV]

Hello GrantV,
what test on bench ?
take care with SKP and DR interruptor.

The scope signal I attached was from a current sense transformer while driving the coil directly.

I am however seeing exactly the same 800uS pulse rate (1250 BPS) when I scope the output of the interrupter, so the problem is not in the driver, it is definitely the interrupter that is causing the problem.

As I am not getting any response from the developer, I am seriously considering throwing it away, ordering the parts and building my UD2.7C and a standard interrupter ......

[Kevindk9]

The pulse width (on time) is working properly but at minimum frequency (bps) I am seeing just 800uS between bursts, which is 1.25KHz.

I noticed this too, you can fix it by opening the interrupter and on the back of board there are two capacitors, change the small one to 470nf to bring the frequency between 10-300hz.

The interrupter is just two 555 timers, one is connected to an lm393 comparator and audio input to create the pulses for the audio modulation, and the other controls the pulse width and frequency.  The SKP/DR switch just switches between two capacitors to control the different pulse widths and frequency ranges.

I figured out quickly you can not play normal music through the interrupter, but i figured out you need to download a midi file and open it in VLC media player.
but in order to play midi files in VLC you need a sound font file that turns midi notes into square waves, i used this one https://www.polyphone-soundfonts.com/documents/24-sound-effects/470-square-wave-soundfont  I also found out it can really only play one or two notes at a time.

[GrantV]

The pulse width (on time) is working properly but at minimum frequency (bps) I am seeing just 800uS between bursts, which is 1.25KHz.

I noticed this too, you can fix it by opening the interrupter and on the back of board there are two capacitors, change the small one to 470nf to bring the frequency between 10-300hz.

The interrupter is just two 555 timers, one is connected to an lm393 comparator and audio input to create the pulses for the audio modulation, and the other controls the pulse width and frequency.  The SKP/DR switch just switches between two capacitors to control the different pulse widths and frequency ranges.

I figured out quickly you can not play normal music through the interrupter, but i figured out you need to download a midi file and open it in VLC media player.
but in order to play midi files in VLC you need a sound font file that turns midi notes into square waves, i used this one https://www.polyphone-soundfonts.com/documents/24-sound-effects/470-square-wave-soundfont  I also found out it can really only play one or two notes at a time.

Hey Kevin, lol thanks for that and well done for figuring out the problem :-)

As I have since replaced that controller with a UD2.7C, built my own interrupter and am the proud owner of a MidiStick, I doubt that I will need to go back and fix this controller, but it's good to know that there is a way to get it working if I ever need to throw something together for a small project in the future 

[henryj]

I wish to use the hand-held interrupter with a UD2.7C driver, but the PN for the fiber interface is BLT1120.
Shouldn't this be a DLR1120?