BS-1 turning off a desktop computer
AJ-9000
Posts: 52
my project involves(not very often) having a BS-1 turning off a desktop computer in a
way where the computer in effect shuts it's self down, one idea I have how to do it is to
turn off power to one of the computer fans that RPMS's it monitors and when the fan stops the
computer turns it's self off because it is programmed to shutdown in that event.
By using a relay located between the fan power jack(located on the computer mother board) and
the fan my question is, even though the fan only uses 100 milliamps is this the best way to
do this or would it be better to use a solid state relay or have a solenoid in effect
mechanically stop it ?
Thanks
Post Edited (AJ-9000) : 9/8/2006 2:17:24 PM GMT
way where the computer in effect shuts it's self down, one idea I have how to do it is to
turn off power to one of the computer fans that RPMS's it monitors and when the fan stops the
computer turns it's self off because it is programmed to shutdown in that event.
By using a relay located between the fan power jack(located on the computer mother board) and
the fan my question is, even though the fan only uses 100 milliamps is this the best way to
do this or would it be better to use a solid state relay or have a solenoid in effect
mechanically stop it ?
Thanks
Post Edited (AJ-9000) : 9/8/2006 2:17:24 PM GMT
Comments
Messing about with a fan may sooner or later result in something overheating...
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Don't visit my new website...
Shutting the fan off is not a good idea... The reason the PC is "programmed to shutdown in that event" is because the lack of a fan causes
overheating and your resulting shutdown is due to thermal reasons. I had a PC that started doing this because the power supply fan failed. <- $10
later for a new fan and it still works today.
What I would do, and this certainly is not the only solution, would be to use the Stamp as a "dongle" off of the Parallel, Serial, Audio, or Game port.
When it's time for shut down, the Stamp sends an appropriate signal to the port. Now, through software, monitor the port for the proper "shut down"
signal and when received, issue the proper shutdown command from software. Your software can be written in C, VisualBasic, or what ever
flavor you prefer. Just launch the monitoring software from the .... Start-->All Programs -->Startup directory in windows and have it monitor the
port in the background.
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
OR....
Run a UPS program on your computer and have the stamp serial a command to the computer that the UPS program picks up....the message would obviously be, shutdown, battery below limits...whatever!
The UPS method would allow windows to shut down 'nicely' (but not right away)....where the 5second push would be an 'ugly power down'...after 5seconds of course!
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Steve
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
Above all Beau is right. My computer thermally shuts down, but only after the core temperature reaches a critical level. The motherboard also measures the temperature in the core. Maybe the fan disconnect will merely drive your microprocessor into a critically stressed state before a shut down. That is not good engineering and quite unnecessary.
Also, take a look at your BIOs screen for shut down and turn on options. Some may be provided by the use of keyboards, serial ports, etc.
Shuting down the power switch is really not good either as the computer just crashes. You want an orgainized shut down. My computer has a low voltage ON/OFF switch which tells the computer to do a proper shutdown. That is most likely the switch that you want to connect an parallel switch to. Since it is low voltage, there is very little harm in running a pair of wires out of the chassis to a relay.
So skip dealing with the 120AC too.
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"If you want more fiber, eat the package.· Not enough?· Eat the manual."········
Or you can Jumper the BS2 pins to the Power Switch of the PC and have the BS2 send a signal to emulate a button press.
It may be a workable solution in some cases and yours in particular. But since so many people just lurk and read these postings, we try to keep everyone out of the weeds. Thats one of the things that makes Parallax's Forum special - real help for novices in general.
In some cases,as I mentioned before it may repeatedly thermally stress the core of the microprocessor and no one knows for sure.
Also, it is a quite useful application idea in general. I have BS2s running a CANbus now and if I wanted to turn on and off my computer to have that network migrate data to the internet [noparse][[/noparse]with a PINK or something similar] I would need to handle this is a way that the PC is always maintained in a stable fashion.
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"If you want more fiber, eat the package.· Not enough?· Eat the manual."········