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Simple LED Light Switch

Posted: Fri Mar 05, 2021 1:38 pm
by Adrian Harris
I wanted something to turn lights on and off on the UC and everything I found seemed to have far too many functions, so I have built one myself.

20210305_133055a.jpg

It has two modes, selected at power on by the position of a three way switch.

If the switch is off (Pos 1) at power on then it behaves like this:

Switch Pos 1 LED1 Off LED2 Off
Switch Pos 2 LED1 On LED2 Off
Switch Pos 3 LED1 On LED2 On

If the switch is in the centre position (Pos 2) at power on it works in toggle mode, so if you click from Pos 2 to Pos 1 and back again LED1 comes on. If you do it again, it goes off. And the same for Pos 2 to Pos 3 for LED 2.

It has FET output drivers, so can handle 1A per channel, though most LEDs only use a few milliamps.

Price is £10 plus postage.

Adrian

Re: Simple LED Light Switch

Posted: Fri Mar 05, 2021 2:42 pm
by Tim Page
That looks really good Adrian and a decent price too.
Tim

Re: Simple LED Light Switch

Posted: Fri Mar 05, 2021 4:29 pm
by Mick Regan
Nice one Adrian. Perfect for the Universal Carrier lights👍

Mick

Re: Simple LED Light Switch

Posted: Sat May 22, 2021 9:57 am
by Sam Hough
Dear Adrian,

My Dad has bought one of these and I don't think we have the pin out description. Sorry if he has lost it or I'm being slow.

So the PCB header seems to have two outer pins marked (+) and two inner marked (-). Do these provide power (direct to the LEDs) from the rx lead into the unit or (less likely I guess) just the connections across the FET (although more like a switch)?

I think my Dad has bought LEDs with resistors calculated for 7.4v for the battery pack rather than the 6v from the BEC but shouldn't make much difference.

btw Is very neat and tidy unit.

Cheers

Sam

Re: Simple LED Light Switch

Posted: Sat May 22, 2021 10:12 am
by Adrian Harris
Yes, they are raw supplies for the LEDs, without series resistors.

The absolute maximum voltage of the PIC is 6.5V, though there is a series diode on the power input of the board, but watch the supply voltage.

Adrian.

Re: Simple LED Light Switch

Posted: Sat May 22, 2021 10:16 am
by Sam Hough
Thanks Adrian,

Very poor that I managed to mess up my questions ;) I was assuming no series resistors but then I said "direct to the LEDs". Sigh.

Cheers

Sam

Re: Simple LED Light Switch

Posted: Sat May 22, 2021 5:20 pm
by Sam Hough
I was short of a 4 pin shell for the standard servo connections output so printed one. Openscad source if anyone is in the same position and has a 3d printer...
pitch = 2.54; // 0.1"

w = [0, 0.6, 0.6]; // wall thickness
b = [14, pitch, pitch];
n = 4;

for (j = [0: n - 1])
    translate([0, j * pitch, 0])
            difference() {
                cube(b + w, center = true);
                cube(b - w, center = true);
            }
openscad is free to turn it into STL... I just printed on cheap FDM printer 0.4 nozzle and 0.2 layer.

Dad very happy with working lights.

Cheers

Sam