Question about "turning on computer" without a case.

[purbeast0]

Well that gets the time count going.

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.

 

[sdifox]

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.

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.

 

[purbeast0]

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.

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.

 

[purbeast0]

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?

 

[sdifox]

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?

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.

 

[purbeast0]

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.

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.

 

[sdifox]

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.

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.

 

[purbeast0]

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.

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?

 

[purbeast0]

I just tested it out and yeah the relay clearly clicks on then off after like a second.

 

[purbeast0]

YES I THINK I GOT IT!!

 

[sdifox]

For real? Drink a beer on my behalf.

 

[purbeast0]

For real? Drink a beer on my behalf.

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.

 

[sdifox]

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.

Ground loop I guess.

Ground loop (electricity) - Wikipedia

en.m.wikipedia.org

 

[purbeast0]

Ground loop I guess.

Ground loop (electricity) - Wikipedia

en.m.wikipedia.org

Yeah but I don't understand how extending a power cable (that was 6 18awg wires) could cause it, and then plugging my ATX PSU through the arcade PSU causes it too. I don't see how those could cause these ground loops.

 

[sdifox]

Yeah but I don't understand how extending a power cable (that was 6 18awg wires) could cause it, and then plugging my ATX PSU through the arcade PSU causes it too. I don't see how those could cause these ground loops.

No clue.

 

[purbeast0]

No clue.

You got me this far so thanks a bunch! I'm going to solder it to the circuit board today and then be done with that shit!

 

[sdifox]

You got me this far so thanks a bunch! I'm going to solder it to the circuit board today and then be done with that shit!

I mean remote guessing ground loop issue is impossible xd

 

[purbeast0]

I mean remote guessing ground loop issue is impossible xd

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.

 

[sdifox]

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.

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.

 

[purbeast0]

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.

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.

 

[sdifox]

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.

So arcade psu is isolated from pc psu. Are they plugged into the same circuit breaker?

 

[purbeast0]

So arcade psu is isolated from pc psu. Are they plugged into the same circuit breaker?

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.

 

[purbeast0]

And here is the final product.

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.

 

[sdifox]

And here is the final product.

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.

Well at least we figured it out.