Plasma Torch On During Computer Shutdown
10 Jul 2013 20:51 #36498
by Paul
Plasma Torch On During Computer Shutdown was created by Paul
I usually let me plasma cutter run for awhile without load thinking I am letting it cool down after cutting parts for the day. I almost always turn off the plasma cutter before the computer, but a few times I have been caught off guard by shutting down the computer (using parallel ports) before the plasma cutter and just before the computer is off, the plasma torch is triggered on.
Is there a way to automatically keep the computer from activating the torch relay via the breakout board? I could add a switch to break the relay power, but then I am sure I will forget to flip this switch at some point.
Any guidance or ideas would be appreciated.
Paul
Is there a way to automatically keep the computer from activating the torch relay via the breakout board? I could add a switch to break the relay power, but then I am sure I will forget to flip this switch at some point.
Any guidance or ideas would be appreciated.
Paul
Please Log in or Create an account to join the conversation.
10 Jul 2013 22:10 #36511
by andypugh
It might be enough to change the pin. Some parport pins are hardware inverted, and this _might_ mean that they behave correctly.
A shutdown G-code might be an option (INI file config)
The best solution might be some sort of charge-pump or watchdog circuit.
Replied by andypugh on topic Plasma Torch On During Computer Shutdown
Is there a way to automatically keep the computer from activating the torch relay via the breakout board?
It might be enough to change the pin. Some parport pins are hardware inverted, and this _might_ mean that they behave correctly.
A shutdown G-code might be an option (INI file config)
The best solution might be some sort of charge-pump or watchdog circuit.
Please Log in or Create an account to join the conversation.
11 Jul 2013 09:56 #36540
by Paul
Replied by Paul on topic Plasma Torch On During Computer Shutdown
Thanks Andy,
I did wonder that they were working as designed.Although I have seen the term charge-pump, not really sure what that is. I will also look into adding some type of shutdown g-code. Thanks for the ideas!
I did wonder that they were working as designed.Although I have seen the term charge-pump, not really sure what that is. I will also look into adding some type of shutdown g-code. Thanks for the ideas!
Please Log in or Create an account to join the conversation.
11 Jul 2013 14:08 #36542
by Rick G
Replied by Rick G on topic Plasma Torch On During Computer Shutdown
I think the problem is once Linuxcnc shuts down and no longer controls the parallel port you really do not know what state the pins are in or if they will float.
Best practice is to shut down everything before you shut down Linuxcnc and as Andy said...
Rick G
Best practice is to shut down everything before you shut down Linuxcnc and as Andy said...
The best solution might be some sort of charge-pump or watchdog circuit.
Rick G
Please Log in or Create an account to join the conversation.
11 Jul 2013 16:21 #36545
by andypugh
Something like uk.rs-online.com/web/p/timer-circuits/6867509/
Then you would turn the torch on with an oscillatory output (there is a HAL component called "charge_pump" specifically for this job) and if the oscillations stop (in either high or low state) then the torch turns off.
Replied by andypugh on topic Plasma Torch On During Computer Shutdown
.Although I have seen the term charge-pump, not really sure what that is
Something like uk.rs-online.com/web/p/timer-circuits/6867509/
Then you would turn the torch on with an oscillatory output (there is a HAL component called "charge_pump" specifically for this job) and if the oscillations stop (in either high or low state) then the torch turns off.
Please Log in or Create an account to join the conversation.
11 Jul 2013 18:45 #36548
by BigJohnT
Replied by BigJohnT on topic Plasma Torch On During Computer Shutdown
I just turn my plasma torch off before LinuxCNC and on after starting LinuxCNC. This way LinuxCNC is in control when the plasma torch is powered up.
JT
JT
Please Log in or Create an account to join the conversation.
11 Jul 2013 23:15 #36568
by Paul
Replied by Paul on topic Plasma Torch On During Computer Shutdown
Thanks for the replies. My plan has been to turn off the torch before the linuxcnc computer, but just forgot this time. I do like Andy's watchdog setup. That would help make sure my absent mind doesn't do it again someday.
Please Log in or Create an account to join the conversation.
11 Jul 2013 23:45 #36570
by BigJohnT
Replied by BigJohnT on topic Plasma Torch On During Computer Shutdown
You could wire the off button with about 12v when the torch is on so if you touch it you get a reminder to turn off the torch before the computer.
JT
JT
Please Log in or Create an account to join the conversation.
12 Jul 2013 10:12 #36585
by Paul
Replied by Paul on topic Plasma Torch On During Computer Shutdown
Oh, how shocking.
Please Log in or Create an account to join the conversation.
Time to create page: 0.124 seconds