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**zandrax** · 03-17-2008, 05:46 PM

Re: AT Power supply: how turn-on?

Welcome zgouki.

Japlitic posted a picture of your psu: perhaps he knows the switch cables' color. Quite strange there isn't a proper switch or, at least, two big cable with a connector.

Zandrax

**zgouki** · 03-17-2008, 08:01 PM

Ok, I saw this picture in this forum (attachment). I think that the cables (3) in the circle green in the second picture are the turn-on cables but I don´t know how conect bought...

.
One of them is GND becuse is black, but the grey and the violet????
Thanks for your reply.

Attached Files

**starfury1** · 03-18-2008, 12:54 AM

Re: AT Power supply: how turn-on?

doh posted but not supply I was thinking of

**davmax** · 03-18-2008, 01:49 AM

Re: AT Power supply: how turn-on?

If I remember correctly these old power supplies had a mechanical toggle switch on the front panel. If one lead is earth I suspect the the other two leads are intended to go to a switch that just connects them together to switch on the power supply.

Would anybody like to check me out on that?

**zgouki** · 03-18-2008, 06:15 AM

Re: AT Power supply: how turn-on?

I think the same that davmax,

If one lead is earth I suspect the the other two leads are intended to go to a switch that just connects them together to switch on the power supply.

But I didn´t connect anything because I don´t what will happen.... (EXPLOSION!!!

)

**kikkoman** · 03-18-2008, 06:59 AM

Re: AT Power supply: how turn-on?

the few standard AT PSUs I can remember had a 2xON push switch (going to the front panel via a 4-lead cable) that directly switched both A/C lines, thus no standby mode.

can't see such a cable here, the A/C jack seems to go straight to the PCB. there's a grey block underneath the A/C jacks - could that be a relais?

**PCBONEZ** · 03-18-2008, 07:15 AM

Re: AT Power supply: how turn-on?

What kikkoman said is what I remember.

Usually there was a 2P2T switch with 4 wires.
Hot and Neutral were both switched.
Ground stopped at PSU and did not go to switch.

There were some with a switch inside the PSU that was activated by a rod that passed through the case to the front panel 'button'.

.

**PCBONEZ** · 03-18-2008, 07:33 AM

Re: AT Power supply: how turn-on?

2P2T ??? or 1P2T ??? Been too long...
See picture.

Attached Files

**kikkoman** · 03-18-2008, 07:45 AM

Re: AT Power supply: how turn-on?

2P1T, effectively. i think it was a 2P2T switch, but only single throw used.

**zgouki** · 03-18-2008, 09:38 AM

Re: AT Power supply: how turn-on?

So what I must do?
The out-cables of the PSU are the molex, this cables :

HTML Code:

http://pinouts.ru/Power/MotherboardPower_pinout.shtml

and the 3 cables (black,grey,violet) that are also conect in the motherboard.
I have the motherboard, I turned on the cpu when I pressed one of the 3 microswitch there are in a PCB with 3 indicators-leds. This PCB have cables were conected to the motherboard to, but in other position.
i don´t know what another information i can give you for this problem.
Thanks

**starfury1** · 03-18-2008, 11:06 AM

Re: AT Power supply: how turn-on?

link
http://pinouts.ru/Power/MotherboardPower_pinout.shtml

no comment on the above supply...no idea...

I do I think remember what you guys are talking about...it just dont seem the case with that one to me.
(it was switching 240/120VAC & Neutral and they were spade connectors to a DPST (DPDT) )
..but I could be wrong
the photo is too small and from what I can tell like kikkoman I cant see mains wires going out

no help I know

**PCBONEZ** · 03-18-2008, 06:42 PM

Re: AT Power supply: how turn-on?

Okay, first it's not an AT power supply.
It's some proprietary (custom) unit.

This page:
http://www.a1parts.com/surplus/index.html
... Says "Has 3-prong power on/off connector."
That connector probably connects to the front panel in what ever it is for.

Here:
http://www.cnczone.com/forums/archiv...p/t-39748.html
ericdwilso said:
""There is a 3 position connector for the power switch... I jumpered a pair of the terminals and that started the PSU.""
... Unfortunately he does not mention WHICH pins.

It is made by this company:
http://www.luminapower.com/contact.php
They make custom power supplies.
The FIC Part Number tells me this is something made for FIC.
(I am guessing that FIC = First International Computer".)

The way that is wired it is unlikely AC goes to the on/off connector.
It is probably DC that trips a relay (or transistor).
Yes, Black is probably ground.
Connecting one of the other two (grey or violet) to the ground should start it...
BUT!
BUT!
BUT!
- I don't know if it's supposed to be a momentary contact or a true on/off switch.

The other wire many be intended for a front panel LED or light to tell you it is on -or- for a reset switch. (Just guessing.)

.

**starfury1** · 03-18-2008, 07:09 PM

Re: AT Power supply: how turn-on?

figured it was a proprietary build job,

thats why I wasn't even game to suggest anything

Nice detective work Bonez

regardless

Cheers

**davmax** · 03-18-2008, 07:29 PM

Re: AT Power supply: how turn-on?

Based on the detective work. There are two possibilities
1. The three wires are involved with low voltage DC to switch ON the PS.
2. That AC power is controlled by connecting two wires voilet and grey.

It would be a hazard to connect the two wires without first measuring what voltage exists on them when power is connected to the PS.

Carefully measure what voltages exist on the voilet and grey wires using the black wire as the common. Then we might be able to determine what to do.

**zgouki** · 03-19-2008, 06:58 AM

Re: AT Power supply: how turn-on?

Firts of all, I wanna to thanks to everybody who help me in this topic. I´m really grateful for yours replies!

Finally I coud turn on the PSU

! PCBONEZ and davmax are in correct: I tested with a multimeter (PSU connected to the AC line previously)the grey cable and the violet with the GND (black) cable, and these are the results (all the voltages are DC):
----------
¦ O ¦ <---- Grey : + 2,87V...........................................................
¦ O ¦ <---- Violet : + 5 V.............................................................
¦ O ¦ <---- Black : GND................................................................
----------
When I put this female connector in the respective male in the mother board I tested with the multimeter again, and this is the 2nd result:
----------
¦ O ¦ <---- Grey : + 5 V...........................................................
¦ O ¦ <---- Violet : + 5 V.............................................................
¦ O ¦ <---- Black : GND................................................................
----------
Then I press the micro-switch in the external PCB, the PSU turn on and this is the 3rd result:
----------
¦ O ¦ <---- Grey : ??? V...........................................................
¦ O ¦ <---- Violet : + 5 V.............................................................
¦ O ¦ <---- Black : GND................................................................
----------
Why "??? V" ? Because when I want to test with the multimeter the wires Grey-Black, the LCD say: 0.00 V. Then when I want to test with the multimeter Grey-Violet, I don´t have time to see what the LCD say because the PSU turn off!
But don´t worrie, I finally hit the nail on the head...when grey and violet are connect, the PSU is off; when grey and black are connect the PSU is on, so I should buy an interruptor with 3 pins/2 positions like this:

Any advice will be appreciated. Thanks and good bye buddies!

**PCBONEZ** · 03-19-2008, 06:29 PM

Re: AT Power supply: how turn-on?

Hi,

There are dozens (or even hundreds) of different ways they can do this using IC's, transistors (as switches), or even mechanical relays but the basic idea is the same.
-
Changing the state (voltage) at one pin causes the state to change at another pin or pins.

~~~~~~~~~~

By what you have shown for voltages when the grey wire is grounded the PSU starts.

When you tested Grey-Violet you put +5v back on the grey wire from violet wire (through the meter) and that turned the PSU back off.

Drawing is not a real circuit but should help with understanding the basic idea.

.

Attached Files

**PCBONEZ** · 03-19-2008, 06:56 PM

Re: AT Power supply: how turn-on?

I think this maybe closer to what you have.

NOT FOR SURE! - I can't see it!!

The 2.87v you measured on the grey wire may just be leakage through an IC chips circuits.

.

Attached Files

**zgouki** · 03-21-2008, 10:10 AM

Re: AT Power supply: how turn-on?

Hi again. I´m trying to put this circuit in the PSU...is OK or no?
The led is a blue led and the resistor= 150 ohms. The switch is the same that a told you before.
Sorry, I thanks you for yours replies but I don´t understand what do you told me in the lastes post.
I wanna a simply solution like the mine, but I don´t know if is gonna works or not.
See you and thanks again

Attached Files

**PCBONEZ** · 03-21-2008, 08:36 PM

Re: AT Power supply: how turn-on?

That should work if we have guessed the circuit correctly.

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AT Power supply: how turn-on?

AT Power supply: how turn-on?

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