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Question about "turning on computer" without a case.

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sdifox said:
Well that gets the time count going.
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Yeah but if there was no button and just power was wired to pin2, would the timer just start as soon as it gets power? Or am I just not following correctly?

I quickly tried to make the circuit shown and doing what I mentioned but it didn't do anything, but I was also in a rush so didn't really have time to double check anything and retest.

Also do you have any other suggestions? Just been a busy weekend for me and haven't had much time to mess around with it but now do lol.
 
purbeast0 said:
Yeah but if there was no button and just power was wired to pin2, would the timer just start as soon as it gets power? Or am I just not following correctly?

I quickly tried to make the circuit shown and doing what I mentioned but it didn't do anything, but I was also in a rush so didn't really have time to double check anything and retest.

Also do you have any other suggestions? Just been a busy weekend for me and haven't had much time to mess around with it but now do lol.
Click to expand...

Yeah when you power up the counter starts. Maybe get a 5v relay? That way we isolate the PWRPin from the timing circuit. Get a bunch of smaller value cap and resistors in case you need to reduce time.
 
sdifox said:
Yeah when you power up the counter starts. Maybe get a 5v relay? That way we isolate the PWRPin from the timing circuit. Get a bunch of smaller value cap and resistors in case you need to reduce time.
Click to expand...
Dang so nothing with what i already have lol?

Do you have any idea why when doing the timer circuit like straight up with +5v and ground from the PSU, that when I read from the multimeter pin3 and the +5v that it reads 1.3v while the LED is on, and then once it is off it reads 5.2v? Not knowing much about this, I would have expected it to read 5v while it is on and 0 when it is off.
 
In theory, could I use the 12V to power the circuit with the timer instead of 5v, and then pin3 from the timer would output 12v when it's done, thus activating the relay? Or would 12v fuck up the timer?
 
purbeast0 said:
Dang so nothing with what i already have lol?

Do you have any idea why when doing the timer circuit like straight up with +5v and ground from the PSU, that when I read from the multimeter pin3 and the +5v that it reads 1.3v while the LED is on, and then once it is off it reads 5.2v? Not knowing much about this, I would have expected it to read 5v while it is on and 0 when it is off.
Click to expand...
purbeast0 said:
In theory, could I use the 12V to power the circuit with the timer instead of 5v, and then pin3 from the timer would output 12v when it's done, thus activating the relay? Or would 12v fuck up the timer?
Click to expand...
The timer chip is capable of using 12V but the datasheet only shows value for 5v and 15V so you'll have to play with resistors and capacitors.

I would suggest bigger resistor values, especially infront of the LED. You are going to have higher currents going there.


Check the voltage of the 555 pin3 output.
 
sdifox said:
The timer chip is capable of using 12V but the datasheet only shows value for 5v and 15V so you'll have to play with resistors and capacitors.

I would suggest bigger resistor values, especially infront of the LED. You are going to have higher currents going there.


Check the voltage of the 555 pin3 output.
Click to expand...
WHen you say to check that voltage of pin3, what 2 pins do I use? pin3 and then ground? Because I had previously been doing pin3 and +5v, which was giving me the 1.3v when light onthen 5.12v values when light off, which I thought was odd.
 
purbeast0 said:
WHen you say to check that voltage of pin3, what 2 pins do I use? pin3 and then ground? Because I had previously been doing pin3 and +5v, which was giving me the 1.3v when light onthen 5.12v values when light off, which I thought was odd.
Click to expand...

Pin 3 and ground after led.

A relay would isolate the pwerpin and PWRGRD from the control circuit, making it as close to a button press as possible.
 
sdifox said:
Pin 3 and ground after led.

A relay would isolate the pwerpin and PWRGRD from the control circuit, making it as close to a button press as possible.
Click to expand...
Okay shit well that explains why I was getting wrong readings lol.

Okay so now I am getting 3.95v then it drops to 0 when the light turns off.

If I completely remove the LED from the equation and just do pin3 to ground, I get 4.7v then drops to 0 after a second.

So in theory, could I instead power the circuit with 12v and not 5v, and then run pin3 to relay, and once it goes from 12v to 0, it will flip the relay from NO to NC?
 
sdifox said:
For real? Drink a beer on my behalf.
Click to expand...
Haha yeah thanks for all your help man!

I ended up doing pin3 from timer to coil and PSU ground to coil. Then PWRPin to common and GNDPin to NO and ground to NC.

Now I keep getting this fucking chassis intruded error after I reboot after initializing BIOS settings but I'm like 99% sure it's because my CMOS battery is dead. I had this happen before and then put an old ass battery from my spare key fob for my car but i'm pretty sure that shit was like dead too.

I also need to figure out some screen interference issues that have to do with power. It doesn't have to do with the circuit at all it's when I plug my ATX PSU into the arcade PSU there is noticeable screen interference, and when I use this 6ft power cable I made longer that was originally 3ft long I see more too.
 
purbeast0 said:
Haha yeah thanks for all your help man!

I ended up doing pin3 from timer to coil and PSU ground to coil. Then PWRPin to common and GNDPin to NO and ground to NC.

Now I keep getting this fucking chassis intruded error after I reboot after initializing BIOS settings but I'm like 99% sure it's because my CMOS battery is dead. I had this happen before and then put an old ass battery from my spare key fob for my car but i'm pretty sure that shit was like dead too.

I also need to figure out some screen interference issues that have to do with power. It doesn't have to do with the circuit at all it's when I plug my ATX PSU into the arcade PSU there is noticeable screen interference, and when I use this 6ft power cable I made longer that was originally 3ft long I see more too.
Click to expand...

Ground loop I guess.

Ground loop (electricity) - Wikipedia

en.m.wikipedia.org en.m.wikipedia.org
 
sdifox said:
I mean remote guessing ground loop issue is impossible xd
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If it's a ground issue I wonder if it has to do with the relay or something. It's only happening with the game using the ATX PSU and separate motherboard, Target Terror Gold. None of my other games have any of that screen interference.
 
purbeast0 said:
If it's a ground issue I wonder if it has to do with the relay or something. It's only happening with the game using the ATX PSU and separate motherboard, Target Terror Gold. None of my other games have any of that screen interference.
Click to expand...

relays are isolating so it should not have ground issue. assuming the common pin on that relay with PSON is hooked up to the arcade ground instead of PC ground.
 
sdifox said:
relays are isolating so it should not have ground issue. assuming the common pin on that relay with PSON is hooked up to the arcade ground instead of PC ground.
Click to expand...
Common is actually hooked up to the ATX PSU ground. The coil pins are the +12 and ground from the arcade jamma interface board. There is nothing on NC.
 
purbeast0 said:
Common is actually hooked up to the ATX PSU ground. The coil pins are the +12 and ground from the arcade jamma interface board. There is nothing on NC.
Click to expand...
So arcade psu is isolated from pc psu. Are they plugged into the same circuit breaker?
 
sdifox said:
So arcade psu is isolated from pc psu. Are they plugged into the same circuit breaker?
Click to expand...
Yes they are.

I do get noticeable distortion when I plug ATX PSU into arcade PSU versus when I plug ATX PSU into a different outlet.

Do you think it's worth trying to use the JAMMA interface board ground as the common on the relay instead of the ATX PSU ground? Then when the circuit is open (PSU turned on) it would be green switch wire from ATX PSU and the JAMMA interface board ground the 2 pins connected on the relay. Right now when its activated its the green switch wire and ground both from ATX PSU.
 
And here is the final product.

f1ijWcT.jpg


Fv1yTsf.jpg


Tested it all out and it's working just fine!

Thanks again this was a fun project and a great learning experience. Now I completely "get" relays too and how simple they actually are lol like from a "what they do" stand point.
 
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purbeast0 said:
And here is the final product.

f1ijWcT.jpg


Fv1yTsf.jpg


Tested it all out and it's working just fine!

Thanks again this was a fun project and a great learning experience. Now I completely "get" relays too and how but simple they actually are lol like from a "what they do" stand point.
Click to expand...


Well at least we figured it out.
 
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