shutdown controllers

starfox · 05-03-2004, 10:44 PM

Is anyone here interested in (yet) another shutdown controller? I've designed a circuit that's based around a picaxe08 and works for a Morex PSU or an inverter.

I've built a prototype and so far it's been working pretty well. It does the following:
- relay control for 12V supply to inverter / morex PSU
- simulates pushing power button on motherboard for power on and off
- forces power off if the computer doesn't shut down within some interval
- sense line for accessory
- override power on
- sense line for 5V line (shutdown controller switches off main power relay after this line falls to 0V after the PC has shut down)
- provides an amp power on line (seperate to prevent power on thump from computer)

It's based on picaxe, so i've actually incorporated a programming header onto the prototype (picaxe is really easy to program), so just about anyone should be able to build it. You can change all of the delays by changing the constants in the shutdown controller picaxe program, and reprogramming the microcontroller.

If anyone's interested i'll post the circuit diagram (it's mostly on paper at the moment), and i'll do a stripboard version of the circuit (not going to make PCBs for this, too expensive).

Marsupial · 05-03-2004, 11:06 PM

Would there be a way to tell the computer to shutdown?
I have a kiosk PC that use a 12-24V converter and I have no poweron/shutdown controller... I am not sure I'll use one, but if I'm available to build one, I'm interested.

Ricky327 · 05-03-2004, 11:16 PM

Startfox...post em

Nice to see other design going around. Im too in the progressing of finalising my design...just had gone off course for a bit since my car got stolen

A member called meddler has also based his design on PICAXE, not sure how much more time he needed to finish off his...but definitely its cool to see more comming in

EBJUSTIN · 05-03-2004, 11:38 PM

Quote: Originally Posted by Ricky327

Startfox...post em

Nice to see other design going around. Im too in the progressing of finalising my design...just had gone off course for a bit since my car got stolen

A member called meddler has also based his design on PICAXE, not sure how much more time he needed to finish off his...but definitely its cool to see more comming in

Yes,
Please post..very interested...

starfox · 05-04-2004, 02:29 AM

Okay sure, i'll post it when i've finished testing. There's a few things i need to check first (like if i have to use current limiting resistors on relays), and to stripboard the design.

I'll post the circuit diagrams soonish.

meddler · 05-04-2004, 05:35 AM

most of mine is still in the theory / design stage, but with a little work mine could be completed (i think) quite easily.

@ starfox: Mine is a little more complex than yours and uses a picaxe28X chip. I can send you some more info if you are interested.

starfox · 05-04-2004, 01:01 PM

Tested mine today for a couple of hours driving around, works fine.. only thing i have to worry about is that the relay coils seem to be running a little warm, might see if i can add some caps to provide provide enough current to latch the relay, then just maintain a lower holding current to keep the relay closed.

Mine's just built for simplicity, and the whole thing was a RAD project.. The prototype was designed and the circuit built in about a week in my spare time, and it kinda shows, the current design is quite large and has heaps of wires floating around lol.. I'll rebuild it into something better soon though.

Sorry to hear your car was stolen Ricky... >_<

starfox · 05-05-2004, 06:06 AM

This is the outline for the basic design i'm using:

PICAXE08 program:
http://tartarus.uwa.edu.au/~daveis/c...pplication.zip

Diagram for relay drivers:
http://tartarus.uwa.edu.au/~daveis/c...elayDriver.pdf

You need to vary R1, R2 depending on the resistance of the relay coil that you're using. Similarly for R5, R6, and R8, R9. In my circuit, RLY1 and RLY2 have 200 ohm coil resistance (i'm using a 3A PCB relay), and RLY3 is a 30A automotive relay with 80 ohms resistance. You need to adjust these so the transistor is in saturation.

R3, R4, R7 are current limiting resistors so the PICAXE doesn't have to do too much work.

D1, D2, D3 are protection diodes so the back EMF of the relays doesn't destroy your transistor in the long run. 1N4004s are fine instead of 1N4001s.

U1, U2, U3 are optoisolators. I chose to use standard 4N28s because they're quite cheap and they work. ^^ Using an optoisolator + transistor might seem a bit excessive but i found that the optoisolators became quite warm after supplying the relays without a transistor. Since this circuit has to sit in a car which might get quite hot, i decided that using transistors would be a more robust design.

Q1, Q2, Q3 are standard PNP transistors. You can replace this with just about anything with an hFE > 100, though BC327s should be common everywhere.

The inputs labelled Pin4, Pin7 and Pin5 are the respective pins on the PICAXE IC.

I don't have a diagram for how to wire up the rest of the circuit yet as my circuit design software doesn't have a model for a PICAXE or PIC at all.. Does anyone know of software which'll let you draw a circuit with a PIC in it? (i hope i don't have to use MS Paint ^^)

Gutter · 05-05-2004, 11:08 AM

For those who don't wish to use such a complex controller, the same task can be accomplished with a 12V relay, a diode, and some C code.

I have connected a 12V relay connected to two pins on my parallel port and powering it with the car's power. When the car is on, the voltage is 14.4V and the relay closes the circuit shorting out the two pins. When the car is off, the voltage drops to around 10V and the relay opens the circuit.

I then have some simple software that monitors for changes to those pins. It does nothing when the pins are shorted, but when the relay opens, it initiates a shutdown process.

Ricky327 · 05-05-2004, 05:48 PM

For those who don't wish to use such a complex controller, the same task can be accomplished with a 12V relay, a diode, and some C code.

I have connected a 12V relay connected to two pins on my parallel port and powering it with the car's power. When the car is on, the voltage is 14.4V and the relay closes the circuit shorting out the two pins. When the car is off, the voltage drops to around 10V and the relay opens the circuit.

I then have some simple software that monitors for changes to those pins. It does nothing when the pins are shorted, but when the relay opens, it initiates a shutdown process.

How are you turning the PC on?

Its even easier with :

The ignition +12V, resistors and zener diode can be used to apply voltage directly to the serial ports. A customised fake UPS is setup up in the control panel to do the shutdown.

Marsupial · 05-05-2004, 08:46 PM

Quote: Originally Posted by Ricky327

The ignition +12V, resistors and zener diode can be used to apply voltage directly to the serial ports. A customised fake UPS is setup up in the control panel to do the shutdown.

That seams really really interesting...

Ricky327 · 05-05-2004, 08:59 PM

That seams really really interesting...

I have done it before...its only good for a shutdown though as my motherboard dont support the wake-on-ring from completely off.

I have posted a more detailed info in another forum before...cant find it no more though. Theres a page on microsoft somewhere showing which pins of comport does what for the UPS shutdown.

It is even possible to connect the pin of the comport directly to a +12V supply. But Ill rather limit it with a zener diode and resistor to be on a safe side.

If you are interested do a google else Ill dig it out for you.

Laidback · 05-06-2004, 06:25 AM

Quote: Originally Posted by Ricky327

[i]
It is even possible to connect the pin of the comport directly to a +12V supply. But Ill rather limit it with a zener diode and resistor to be on a safe side.

Or just use 5v from your PSU

Ricky327 · 05-06-2004, 08:42 AM

Or just use 5v from your PSU

No because you are sensing if the igntion line has gone off...not the +5V from the PC.

Gutter · 05-06-2004, 09:41 AM

Whoa whoa whoa, you don't want to be connecting 12VDC to either your parallel ports or serial ports unless you want to release the magic smoke. All you need to do is short two pins and have software on your computer monitoring that port. On the software I've written using the ParaPort.dll driver, 0x38 tells me that the relay is closed and to do nothing. 0x78 tells me that the relay is open and it initiates an immediate shutdown.

And it doesn't turn the computer on. I use a momentary switch because I don't always want it to start up when I start the car. It's simply a "shutdown controller."