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SuperGun power switch wiring help

Simon

Simon

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Hi everyone,
I have a 12V LED on off switch I bought off amazon that I would like to use as a power button for my SmallCab Supergun Deluxe V2.1. The Supergun has a dipswitch that enables the "WOPWR" circuit, two connections that when closed turns the power on. I think that's simple enough to hook up a regular switch, but I'm having trouble figuring out how to wire the LED portion of this switch.

I have no idea how to measure the output of WOPWR in a safe way to see the voltage or amperage that it's giving. I also have no idea how to tell if one side is ground or not haha. I'm new to all this electronics stuff.

So anyway, the switch has NC, NO, C, and +, - connections. I am using an ATX power supply, so if I need to I can get 12V from there. I just want to be able to connect this switch in a safe way without killing my supergun! :)

Any help is appreciated.

Thanks.
 
Post the exact switch brand/model number so we can look up datasheet. or post a link to the datasheet.

Normaly these switches do not have a built in resistor for the leb so you can burn it out if powered directly.

Also, details about your supergun/link/pics would be nice to see exactly what you got

But it should not be difficult to hep wire it up, the more info you give the easier it will be to help you out.
 
If WOPWR is used as a power switch for the ATX power supply, then it's likely that one side of the connection is wired to ATX Pin 16 and the other side would be GND.

https://en.wikipedia.org/wiki/ATX

You can verify this with a multimeter to check that one of the screw-terminals goes to Pin 16 on the ATX connector, and the other is connected to ground.

You would wire one of your NO switch terminals to one of the WOPWR screw terminals, and the C switch terminal to the other WOPWR screw terminal, then when you press the button, the switch connection is closed and Pin 16 of the ATX connector is shorted to ground, and your ATX power supply would start.

As for the LED, you would need to pull power from somewhere on the supergun to the +/- pins.
 
Wow that makes a lot of sense! Thanks :)

So I checked the connectivity, and oddly they both connect to ground, and I don't think they connect to the Pin 16.
 
Simon said:
So I checked the connectivity, and oddly they both connect to ground, and I don't think they connect to the Pin 16.
Click to expand...
Its probably jumpered, why you see ground on both??

2020-07-02_13-27-00.jpg


And yeah, very little info on those switches regarding the led, no voltage drop, etc...too lazy to to do math right now.

But here, is this what your switch contacts look like?

2020-07-02_13-17-19.jpg
2020-07-02_13-16-48.jpg

So yeah, like benime already explained. NO & C got to WOWPWR
+/- would go to 12v on the either the supergun or on the ATX power harness.

Alternately, you can wire that switch to the ATX supply itself, but kinda defeats the purpose since it already has a switch.
 
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Yup, that's how the switch looks. I can easily get power for the led from the PSU rather than prodding around the board. It does sound like I need to control the amount of power going in though.

My supergun model is slightly different, it seems like the older model connected the terminals with a jumper, but my model doesn't need a jumper to power on by default. To "enable" the WOPWR terminal you have to turn off a dipswitch. Both positions don't seem to change anything when I check the connectivity.

I realized I could just test by powering it on with the dipswitch set, so I did that and it powered on anyway... I decided to trace the leads and found that it didn't connect to sw1, but to sw2. So the manual is wrong! Oops!

With the correct dipswitch set, it does indeed connect to pin 16, and the supergun does not power on automatically.
 
The only issue is the led, if it has a builtin resistor or not, most of these switches dont.

What color led is in the switch?

To calculate your resistor value needed to power the led:

Example, leds have a Forward Voltage (Vf)
red, orange, yellow and yellow-green LEDs have a Vf of about 1.8 Vf
while pure-green, blue, white, and UV LEDs have a Vf of about 3.3 Vf.

So, if you have a yellow led on the switch, the voltage drop (Vf) will be about 1.8 V

If your power source is 12V, and your Leds current rating is 15ma
Use this formula to calculate what size resistor you need.

red, orange, yellow and yellow-green LEDs have a Vf of about 1.8 Vf
Source Vf
12v - 1.8 = 10.2v

10.2v / 15ma = 680 or 10.2 / 0.015 = 680 Ohms


while pure-green, blue, white, and UV LEDs have a Vf of about 3.3 Vf.
Source Vf
12v - 3.3 = 8.7v

8.7v / 15ma = 580 or 8.7 / 0.015 = 580 Ohms

Doesnt have to be exact a little higher resistance its fine, for the 580 you could get a 600 Ohm resistor, etc..

Hope my math is good :D Double check that.
 
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What a great post thanks! I always knew LEDs needed resistors but didn't know how that worked, that was very informative. I have a bunch of 300ohm resistors, I will chain two of those since it's a white LED I believe.
 
It does! This is a knockoff version, the PicoPSUs were kind of expensive to get here in Canada, I got this RGEEK one which claims to output up to 17A. I chose a 12V/5A power adapter for it, since I knew that the games I wanted to run off of it didn't require that many amps. I've even heard stories of people powering TGM2 from a 5V phone battery!
 
Arcade PSUs don't draw as many amps as people think. Of course there are exceptions but most boards require less than 3A.

Single slot MVS is less than 1A.
Double slot MVS is just under 2A.
CPS2 is around 3A.

Most single board PCBs fall within the above ranges.
 
USB-C power is very cool! Would love to see more of that in superguns :)

Do you happen to know the power draw of a System 16B? I heard that 3A isn't enough.
 
Simon said:
USB-C power is very cool! Would love to see more of that in superguns :)

Do you happen to know the power draw of a System 16B? I heard that 3A isn't enough.
Click to expand...
USB-C was able to power the consolized Neo because it can be modified to work on 5v only (the components used on MVS and AES are roughly the same and AES operates on 5V)

Most boards require 12v for sound and others need -5 so it would be much more difficult and potentially not possible to run many boards on USB-C because all 3 power rails need to have enough amps.

The maximum output of USB-C is approximately 100W and requires a controller to activate, and it would then need to be regulated down which would lose current as the voltage is dropped.

100W would allow for up to 4A on the +5 rail which could also be used with a Negatron to cover -5 (which only needs 0.5A max) and 1A on +12

It could potentially be done but it would be expensive, not work on all boards and would be a much larger Supergun than Minigun/Parsec/HAS etc.

S16A should be ok with 3A, they're inefficient mainly because the caps and components are old. You may need a bit more to get it to fire up.

Sorry for the thread derail, I like that switch, I've ordered several of those for my console MVS and I've been waiting for them to arrive from China :)
 
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