I have some poorly designed PCB board (LED dimmer), through-hole mounting. The output is in the left corner, it have 8 x 0.1" pitch pin mounting holes for connecting line-in, power, and output (H,M,L,+). Signal input is placed right near the power pins, which is simply wrong. The worst thing is that place with mounting holes in PCB is too small for standard 0.1″ (2.54 mm) Screw Terminal Blocks. The exact pad size for this 8-pin output connector is only of 20 x 6 mm. For this tight header, I can only use 0.1″ (2.54 mm) male header pins, which it not suitable to use in LED Dimmer.

Can anyone advice what connector can I use in this case?

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    \$\begingroup\$ Power next to signal is not an issue for some type of signals. If they have intended a less robust header type for the board, that may be because for the purpose using male header pins or some kludge is harmless. Am I correct in understanding that the drilled holes are too small for the header you want to use, which uses slightly larger square pins? If your project is small quantity or a one-off you can file down the pins in the screw terminal header to fit, so long as the spacing is correct. You could also drill out the pins in the board, but that requires more tools and skill. \$\endgroup\$ – K H Dec 27 '18 at 22:28
  • \$\begingroup\$ It's one-off project, measuring with a regular ruler, the spacing is correct. I tried on some OEM terminal block that were in the local component store, the choice was small, the terminal pad shape were larger than pad on PCB, and flat pins where wider that holes. Possibly I should try another, branded terminal blocks like Molex. Based on Molex drawing, it looks it should fit. (6,5 x 20,78 mm which close to pad size). \$\endgroup\$ – triwo Dec 27 '18 at 23:15
  • \$\begingroup\$ Yes. There are probably hundreds of similar connectors so if cost and shipping times are no issue getting one that matches well is a good plan. As long as pad size is adequate and no unintentional cross connection occurs, filing down the pins on the terminal you have is almost certainly adequate. The metal of the pins is not hard or tough so they are easy to reshape with sandpaper, a small file or a Dremel(rotary tool). Ampacity of the terminal must be adequate, but exact geometry should not matter for your project. \$\endgroup\$ – K H Dec 27 '18 at 23:30

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