I have never seen a manual for a speed/foot controller. I do not know how to check with a multi-meter. I see you are in Algeria, so your voltage is different. I did a search for the Cat Number "CR513" and came up with several references on ebay such as
https://www.ebay.com/itm/TESTED-Vint...-/154267825430. If they have a back side view, it will show a Singer controller with the same Amps and much of the same Part Number. I have had John switch out controllers if the cord and plug were correct for the sewing machine. That is an unusual plug (from what I have seen) and it appears that the when I have searched for the Part number or Cat number they all come up with the same plug.
I noticed in your picture that there are metal pieces/rods that I'm not familiar with. It appears that yours has a chain that is attached to the bottom of the controller with a screw. It also looks like there is a metal rod on the top side, that I haven't seen anything similar to.
Some of the controllers I have seen have screws under the rubber pads, that need to be removed to disassemble the controller.
Sorry I couldn't be more help.
Janey - Neat people never make the exciting discoveries I do.
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