To construct the schematics you should post as good as possible pictures of bottom and top of the board, as well as any markings that you can read.

 

Have you seen the album? (***************)

 

The bottom is too blurry to see anything, could you get some better photo? What is the type of Q1?
Could you take a sharpie and blacken out all the traces connected to ground? Where does the fire signal connect to the bottom?

 

There is no clear name on Q1 so I can't find it on the internet (mor0cc00 P40 yut)
if you will find somthing thank you. aboute better photos my camera cant fucous so close to this board... but I can do it again.

 

morocco is country of origin, but I couldn´t find anythink close to the rest, isn´t there some other line?

If you have like 5Mpix or better camera, try staying far to let it focus, and the zoom it in in software. Or a magnyfying glass in front of the lens should allow you to get better photo.

 

Yes the suply voltage is 12v, the controll pin connected to pic18 micro controller.
I think it doesn't have enough current to turn on the mosfet and therefor Q3/4 darlington.

I don't know what that part of the circuit is doing.
I don't see it as a Darlington. I can't see the board clearly.

About the upper circuit I think I found the little ic ocs, but it's too advanced for me...
Please tell me what is it: http://cds.linear.com/docs/Datasheet/1871fe.pdf

It's a wide range flyback and SEPIC boost converter.

You can download LTSpice IV from Linear Technology's site. It's a good and free SPICE tool.
You have an inductor marked VP5-0155. This is a transformer that has 6 coils rated at 9.9uH, 2A. I will hazard a guess that they are using 1 of the inductors as a primary winding, and the other five connected in series as a secondary winding, using it in a flyback configuration. Or, they could be using more than one coil in parallel for the primary side, and multiple for the secondary side.

There is a high-power SLIC supply on page 36 in the datasheet (last page). This is likely where they got the starting idea for the supply you have, but they simplified it a lot, eliminating Vout1, the opamp, etc.

I can only guess that your MOSFET Q1 is performing the switching on the primary side of the inductor.

You are going to be pretty much on your own with this. I really do not have much time available. Your time is worth money. You might be better off working some extra hours so that you can afford to purchase another module - and be more careful with the next one.

 

Thank you for your help.
I will need anyway constructing this schematics for my project test...
I just need to figure out the last circuit of the LTC1871.

This is the most up to date schematics I have:

I think I found the ocs circuit with the vp5-0155 (look page 31): http://www.datasheetcatalog.org/datasheet/lineartechnology/18717f.pdf [our Q1 is Q9 in the pdf].

They have changed it a littel bit, if you can help me understanding this circuit and how they calculate their Vout I will thank you a lot.

 

In LTSpice they have a model defined for the LTC1871.

I used their example test jig, threw a couple of quick modifications in it, and came up with a quick example of what yours might look like.

I could be way off, this is just a quick and dirty simulation.

L1 and L2 are in parallel on the primary side, but L2 isn't actually used in the simulation. It was just a quick effort to see if I could get it to work.

See the attached.

[eta]
I did this simulation a few hours ago; before you made your last post.

If yours is not the basic part number, you need to let me know.

I don't know which schematic you are referring to in the datasheet you linked to.

 

Its grate!! now the last thing before I am constracting it, how it's connected and charging the capacitors?? from Vout?

Thank you.

 

Like I said, I just threw the simulation together quickly based on some wild guesses, the inductor you have on your board, and an example that was in the datasheet for the LTC1871.

C1 represents all or part of that 6-capacitor bank that's on the same side as the inductor. One or more of those caps might be used for the primary side; but you have them shown as all connected to D2/Q2/R1. You might be accurate, but you may not be.

In your schematic, there is a ground connection missing on one side or the other of R1; I don't know which.

 

Finally its all come together.
I have constructed the osc circuit:

Can you simulate it for me please?
if it's good I will be able to construct the whole schematic!!

Thank you.

 

That's almost exactly what I had before, except L3 is in parallel on the primary instead of in series on the secondary.

The resistor values I used were not quite standard.
Did you really map out, measure and trace out all of the components connected to the LTC1871? Or did you just take my schematic, and move L3 around?

 

I really measured and maped it, (it was extreamly hard hh.... Without the capacitors.

 

Alright. 470k is a standard value, but 6k is not; it could be 5.9k, 5.97k, 6.04k, 6.12k, 6.19k, 6.2k?

What is the actual part number for Q1?

Also, R5 should not be in series with C3; you must have made a mistake there. R5 completely negates C3, which is supposed to be the bypass capacitor for the Vin supply.

 

It's 7.28K I checked again...., Q1 is unknown (m0r0c00 , yot430 , p40n5, ST, 10L ,MRC) if you will found somthing it will be great.
About R5 you right I have mistaken, it's come between pin 1-9 (betwwen RUN to Vin)

Thanks.

 

And R6 is actually about 470k, right?

If so, the output should rise to around 84v and stay there. Is that what you were reading before it blew up?

 

The latest simulation is attached.

Note that CC is still very small; if I used the actual uF, it would take a very long time to run.

 

R6 - is 7.4K , R7 - I cant measure it because of larg capacitor that charges all the time and changes the resistance.

* I think I found Q1 - http://pdf1.alldatasheet.com/datasheet-pdf/view/24432/STMICROELECTRONICS/STP4NK60Z.html

**I am sorry I will see you tomorrow, I am sure you could solve this

Thanks.

 

What voltage did it used to charge up to?

I don't think that's the right MOSFET. Rds(on) is way too high. That's a high voltage MOSFET.

Realized that I had R6 and R7 swapped in my simulation - I just re-designated them.
If R6 is 7.4k and R7 were 560k Ohms, you'd get around 98v out.

But, you haven't told me yet what voltage you were getting out of it when it was working - either that, or I just forgot where you'd written it.

 

Hi,
I am using 12V from battery as power suplly to this driver.
When it was working it gives 100v-110v from the capacitors.
I now checked the resistance again and its appear that R6 and R7 are both 7.4K.

thank you.