Hello, I’m a new member, I hope this is the right place to ask. I’m using an ATX power supply for a car stereo amplifier in home. What id like to do is auto power on the PSU. Since it works differently as say an amplifier (any +12v turns it on) this seems a little tricky. Ideally I’d like to connect the green PS_ON to something in my audio receiver, so when that powers on it kicks on the PSU which kicks on the amplifier. Is this possible somehow?
There is usually a wire from the receiver (blue maybe) that is for turning on a power antenna or Amp.
Since it is 12v you will need to use it to trigger a relay that connects the green PS_ON wire to ground thereby powering on your amplifier.
How does this involve Arduino?
It seemingly doesn't, but there's plenty of examples in this sub-forum of things that don't involve Arduinos. I'm not a moderator, but I see no harm, and the information might be of use to someone who has an Arduino-related similar idea, so let it play, I say! Otherwise, anyone asking about how to wire an LED or relay to a 5V supply must be discouraged from participating. This sub-forum is, after all, "General Electronics".
2 Likes
And you did use a disclaimer. You're all good.
It really doesn’t. Honestly I just googled atx power station forum and ended up here. With the Blue 12v lead I believe you’re referring to a car head unit. I am using a home audio receiver. so I’ll have to open it up to tap into something. But yes, the PS_on just needs a ground. I just can’t imagine what inside the receiver could trigger the ground while powered on only. Sounds like you’re saying I’ll need to use something inside to power a relay which connects ps_on to ground, would this work? relay 12v | eBay
Well then, you're probably in not the best place to get an answer, but maybe we can hook you on programming microcontrollers along the way!
Regardless, have a nice day and good luck with your project.
Maybe construct a circuit + enclosure using a current meter.
Sense when the receiver draws power and switch your PS_ON line. Avoids opening up the receiver and poking around in there.
Well alrighty. In an ATX form factor PDU the green wire is pin #16 on the Rev 2 24 pin PSU design and pin #14 on the older 20 pin Rev 1. Either way it's the only green wire. The 5.0 volt (always on while PSU switch is powering the PSU holds a logic high (5.0 volts) on the PS_ON line. Momentarily pushing the momentary push button on the computer will momentarily place the PS_ON at a logic low (Ground any black wire).
How you choose to go about it is up to you. Again, the process is placing a logic low on the green wire momentarily simulation a PC front panel button press.
Ron
Yes. I know that stuff. So I just have a green and black connected for now and use the case switch for on/off. I just need to find a way to do it automatically when reciever powers on and the “ground for power on” is a little confusing for me. If it was a 5v or 12v signal or something that would be simple
If you measure the green wire to ground you will see 5.0 volts. This is from the 5.0 volt standby. The 5.0 volts is held high by a pullup resistor. Placing the 5.0 volts at ground starts the PSU. If you want to do it automatically using a signal from your receiver just find a signal which has a voltage when the receiver is powered on. I have no idea what your receiver has available when it powers on. Find a voltage available when the receiver powers on like a receiver PSU line and use it to power a relay for example. Let the relay switch your ATX PSU on switching the green wire to ground.
Again, not knowing what receiver you have, seeing a schematic of the receiver I have no clue what signals (voltages) are available when your receiver powers up. Only you know that.
Ron
A perfect job for an optocoupler.
Yamaha rx-373 , could you give me an idea of what relay I need? I can probe inside the reciever to find a proper lead. Would this relay work? relay 12v | eBay
Likely as you don't need much. I also like the idea of using an opto-coupler as mentioned. This all begins with finding a signal in the receiver be it 12 volts, 5 volts or anything useable available when the receiver powers on. The PS_ON is not a matter of switching any current to speak of. While I never measured it we can figure any switch will work. This includes a simple opto-coupler. Just remember whatever you use for switching if a relay you need whatever the relay coil voltage is available. If the receiver has a 12 VDC line then a simple relay with a 12 volt coil or an opto-coupler will do fine. Nice thing about an opto-coupler isolation aside is you place a resistor in series with the emitter half so you can have a wide voltage range turn it on. There are several ways to get where you want to go.
Ron
So it sounds like one of these will work? Could anyone draw on it which wires would go where? Lead from receiver and green and ground from atx psu? I have never done anything like this before and trying to avoid trial and error with it… the inputs on the other side, from bottom to top are dc+ dc- and in
As said, try an opto coupler. Cheaper and far more reliable. No concerns that the load will be too heavy for your receiver or that it the coil will cause emf into your receiver...
A simple npn transistor in common emitter configuration will work. Connect the collector to the green wire and the emitter to ground; base through a 12k (about) resisitor.
When I searched for octo coupler that is what came up. Could you link me an example of one? I know nearly nothing about this stuff. Was just last week I realized I can use an atx as a good 12v DC high amp power supply for something other than a PC…
You have found a relay with opto coupler.
Look for 4N25 opto coupler.
Ok, one of these? Could you help me on what connects where? Seems like I’m working with 3 leads. A power on from reciever and the ps-on and ground from PSU
Yes. Read the documentation...
Things that Google can answer should not be asked here.
If you cannot find it or do not understand the documentation, we are most willing to help...