Ok guys here we are now for the remote power supply. I prioritized this part because a guy from the ieoc forum would like to know more about it.
So whats our goal here:
– remotely switch on/off our equipment
– we want to this quite comfortably from the whole world (I do it with my cell phone 🙂 )
– should be affordable and less than the other remote power supplys you can buy for sometimes a lot more than 100$
So what do we need:
– (0,50$) an opto-coupler (I took a “4N 25”)
– (0,80$) a low current relais for 12V DC with a on/off function
– (1,00$) a mid current relais for 12V DC with a 2-circuit on/off function
– (2,00$) a high current relais for 230V AC (can switch up to 3000Watts), for the people in other countrys who do not have 230V AC power, you should use simliar parts that support 110V AC; the relais needs to be able to switch 2 circuits
– (0,10$) 1x 75Ohm resistor 1/4W (to protect the opto-coupler from getting blasted)
– (5-15$ at ebay) a cisco router with at least two ethernet ports (I used a Cisco 836)
– (take it from garbage or ebay for less than 5$) a (preferably small) network device with a Link-LED that is permanent! The Link-LED must not flash until activity (I used an old SMC Barricade router for this)
– (few $ on ebay) a small 12V power supply
– (borrow it or maybe you own one) soldering iron/gun
– medium skills in electricity
– (2$) a small sized circuit board
– a cross-over cable
– (2-4$ a little box (made of plastic)
– (4$) a 6x electric socket
– (3$) a 3x electric socket
Overall costs are about 30$ to 40$
WARNING WARNING WARNING
When you are working with 110V/230V AC. BE CAREFUL!!! DO IT ON YOUR OWN RISK!!! You should definitely know what you are doing and how AC current works. You should be aware of how to work with voltage and current! I am not responsible for your doing and it is not my intention to let you hurt yourself! Like I said – you do it on you own risk!
I for myself am familiar with electricity and I am allowed to work with voltage
WARNING WARNING WARNING
So lets begin. Maybe you wonder, “why is this guy buying all this crap?” but you will see :). By the way it actually does not matter where we begin so dont blame on me with the order of the steps please :).
General Idea of the concept:
The idea is to do the following. I want to logon to the Cisco 836 via telnet/ssh. Then I will go to a fast ethernet port and hit “no shut”. The rack powers up. When I want to power it down, I type “shut” and the rack shuts down.
The concept itself will work this way:
you logon to the router and “no shut” a specific ethernet/fastethernet interface. This interface is cabled with the crossover cable to the noname-router I mentioned and the link comes up. The link LED of the no-name device is lightened up. We remove this LED and put the optocoupler instead. This makes the formerly Link-LED to a small power-switch that can switch up to 150mA. Enough for the 12VDC low-current relais to be switched on. The low-current relais then switches the 230V high-current relais and that relais switches our rack! So link comes up…CLICK – CLICK (the two relais fire up) and the rack is running.
1st step) – Putting the active components together
Here we need the opto coupler which has 2 connectors for the LED inside the optocoupler to lighten up and 2 connectors that will act as the open contact in the circuit that supplys the low-current relais. First we have to open the no-name router and remove the link-led of one of the ports. Remember that you have to measure where the + and where – is as you need to connect the cathode of the opto-coupler to the + and the anode to the +. A good advice is to measure the voltage that the no-name router uses for the link-LED. When that is up to 3V you better use a the resistor we have in our to buy list to one of the contacts, as this protects the LED in the opto-coupler not to get blasted. Here is a picture how I did it. I took two wires, connected them to the mainboard of the SMC and then attached them to the circuit board and then to the opto-coupler.
Here is the soldering plan how you have to cable the parts together.
We need to connect the low-current relais now. First put it onto the circuit board, then connect the reel with the 12V DC power supply via the opto-coupler in circuit.
We need to connect the high-current relais now. Put it onto the circuit board and connect the reel of it also to the 12V DC (or 230V depends on the operating voltage of the reel) power supply with the low-current relais in circuit.
Cut off the cable (in the middle) of the 6-port electrical socket (you can also use an other socket with more ports if you like to) and wire the 230AC source (where the plug is) to the input contacts of the high-current relais and the outport contacts of the relais to the socket. Be careful that you have a good and solid connection because here about up to 1000W can flow depending on how many devices you want to power.
Power up the DC power supply and put the 230V source for the high-current relais under voltage. Be sure that all contacs are well done and that your safety is the most important thing you should look after.
Connect the port from the no-name router where you removed the led and connected the opto-coupler with the crossover cable to one of the free ethernet/fastethernet ports of your cisco router.
Connect the devices you want to power up to the sockets that are connected to your high-current led.
Telnet/SSH into the cisco and “no shut” the port. You should heat two silent CLICKs and the devices should power up!
Put everything into a box of plastic and fix it with hot-glue for example.
Here is a picture of my complete switch. Does not look like candy, but I am sure that I will build another one that looks quite professional.
If you have a server connected to the remote power switch, make sure that in BIOS you set the ACPI settings the way that the server will power up as soon as power is connected. If you do not, the server will stay offline when the 230V AC comes back. You then could fire it up using Wake On LAN if you have the possibility to.
So thats roughly all I guess. If you are missing something. Just write a comment and I will try to answer your questions.
Here is a video where you can see that it actually works.
Regards and have fun with this affordable self-made solution!