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I would like to use blender PSU board. enter image description here

To power motor of the blender. Whole blender consists of this this board, control board (which blew up) and motor itself. I am now trying to hack this board to output power and use arduino (with some mosfets) instead of control board.

I know this is some kind of AC to DC converter (the motor itself is DC, I powered it with my Lab bench power supply and it spinned). I tried to trace all connections with multimeter and found datasheet (LNK362-364) for chip between diodes (left bottom on the picture). All I was able to get was a DC voltage jumping from 2V to 30V, measured from LNK's pins (pin 5 and 7). I imagine that is rectified sine wave (but I don't have oscilloscope to prove it). I wasn't able to get stable DC from this board, I guess I have to plug somewhere around these caps, but where to get reference point? There is transistor under the white goo, I guess it could serve a safety feature for the board. enter image description here

The pins on the top was where the control board was connected. I tried to measure, connect them, but with no luck. I am kinda lost now, where should I go next, to obtain power from this little device.

One more photo from the back: enter image description here

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    \$\begingroup\$ Did you fix it? what is the voltage on U2 pin 7,8 w.r.t 0V or across adjacent cap \$\endgroup\$ Jan 22, 2019 at 23:16
  • \$\begingroup\$ If the control board blew up - it's very likely it's this board that blew it up. \$\endgroup\$
    – james
    Jan 23, 2019 at 11:17
  • \$\begingroup\$ The LNK chip is a switcher that is usually used to provide a low (3-12V) supply for the controls and display circuitry. You'll find that voltage across the electrolytic top left. The motor is almost certainly a universal, which will work on DC, but is in this case speed controlled by a chopper using the triac TR2 that is on the extruded heatsink. One of the motor terminals would then be common with the incoming power - assuming the terminal at the bottom of the board is "M" then it is connected to L1 via the fuse. \$\endgroup\$
    – Phil G
    Jan 23, 2019 at 16:28
  • \$\begingroup\$ I was able to get 100V DC between two points on the board and then I realized that I don`t have anything to drive this much voltage. So there must be thyristor or something on the board (they had.to vary it somehow as well). Thanks to @PhilG very usefull comment I am sure it is thyristor. Also, thanks to his point with low voltage, I am now able to get 9.5V across the cap he mentioned and power arduino with that. Yay! Now I need to study how to drive the Triac, I dont have many experience with that, only way I know is with FB rectifier + optocoupler. This was probably placed on the faulty b. \$\endgroup\$
    – Kudlas
    Jan 24, 2019 at 22:05

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Unless you are comfortable with and competent to work with AC Mains power that is NOT isolated, you probably should not attempt this project.

The clue that this is dangerous is the blue and brown wires on the right-side of the board. This board is powered directly from the AC Mains and there is NO isolation from the mains.

All that said: if you want to proceed, you need to do some work.

The very first thing to do is to trace the board out and create a schematic diagram showing all of the parts on the board and how they are connected together. Modify your question by adding the schematic that you created.

Only then can anyone else provide meaningful advice.

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  • \$\begingroup\$ easiest way to create a schematic is to print out an enlarged image of the board .... use a camera or a scanner or a photocopier to obtain the image ...... then draw the components on the printed image \$\endgroup\$
    – jsotola
    Jan 23, 2019 at 4:38

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