Thread: Electronic Home Switch

Hi all, as my new router build is almost finished, I intend to use the hall effect home switches as per the CNCZone thread, very long thread if you are interested but most of the important information is in the first few pages.

My machine is using my own design Breakout Board and the inputs are opto isolated, requiring a positive 24 volts to work.

RomanLini's circuit makes a sinking switch, which I cannot use, so I designed a very simple circuit to work with my machine, it might be of use to others here.

Using three components plus the hall effect sensor and terminals this is as simple as I could make it, the idea is to get the machine to mill a blank PCB in its early stages of operation, so I used large spacings that will allow for new machine "character" and hopefully allow a working PCB to be made with a new machine.

Easiest way I can think of to share this is to share the DXF of the copper tracks, mirrored, so you just mill the copper as is, drill the holes then flip it over, solder in the components and away you go.

Please note I haven't made this board yet, plan to on the weekend so it won't be tested until then.

Parts are an LED, the SS441A sensor - hall effect, a PC817 opto (this won't make the home switch optoisolated, just using it to make things simpler),and resistor to suit your home switch voltage, I am using 24 volt, the resistor needs to limit the current to 20mAmps, so allowing 1.2 volts voltage drop across the LED and PC817 combined the resistor is 22.8(24-1.2) divide 0.02 which is 1140 ohms.

I normally use a small V cutter for this kind of work, machine a 0.2mm isolation track and get it to make punch holes for the drill holes and then just drill them out with a drill press by hand. Of course you can get the machine to do the drilling, it is a deeply personal choice.

Cheers.

Russell.