Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
Greetings Mr. O'Reilly The 22ns you refer to is switching time of the output chip. What would be meaningful is response time from an input to the port and the corresponding output after processing time. Of course all of it will be very quick compared to the response time of a heater. I think what is being neglected in this discussion is emphasis on the ability to measure several things and graph them and store the records for later use. Transducers are a fascinating study and the heart of interfacing digital computers to the physical world. Don't forget backup failsafes. Any accidents in this fledgling enterprise will be blown all out of proportion to the public. Home processing could be banned for example. The people that own petroleum don't want competition. Kirk --- Paddy O'Reilly [EMAIL PROTECTED] wrote: Hi, I've been thinking about using old PCs to do exactly this job for ages and for work I've used LabWindows to drive the parallel port for a host of stuff. I've been looking at using plain old DOS6.22 and freeware TurboC for control. Most parallel ports are bi-directional (well on any PC that still works), TurboC can be quite compact and when you run it under DOS there are no crazy Windows traps to fall into. I tested the PC port of an old 90MHz Pentium and I think I got 22ns switching rates from it. However, I haven't managed to get the time or useful purpose for any of my ideas yet but I'd be delighted to give you as much info as I have on controlling parallel ports and my limited knowledge of Turbo C. Paddy. . __ Do you Yahoo!? Yahoo! Mail - Find what you need with new enhanced search. http://info.mail.yahoo.com/mail_250 ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
If you use a 90MHz PC, the instruction cycle time could be around 11ns and faster for higher speeds so if you use a basic DOS or Linux without Windows and something like Turbo C, which should optimise your code, you would get very rapid processing and be limited only by your transducer conversion times which are more in the millisecond (and longer) range for instrumentation. For full control and monitoring you will need much more than a parallel port (or serial port). I favour parallel ports because you can bit bash the ports in whatever protocol the peripheral requires so you can add on I2C devices or any other devices that can be addressable without adding lots of individual ports to your PC. I agree with you about the failsafe aspect - you don't want overheating situations where flash points are likely to be reached - this is where the bi-metallic strip can come in handy - set it to a point below the flash point but above your normal temperature and use it to cut off the supply to your heater (similar parameters to avoid creating a cyclone/twister with your agitator). A couple of years working in the mass transport arena polarises the mind towards taking account of all situations and planning for them. The wherewithal to design and build a multi-purpose analog/digital I/O board has eluded me since I built one for my final year project in university - but maybe one day ;-) Of course there's always a PIC microcontroller which has the aforementioned analog/digital I/O and a development system is a relatively cheap investment - but that contradicts the whole theme of reusing old PCs. Nothing is ever as easy as it seems on first glance. Look on the bright side - if things do go wrong you could have the opportunity to receive an honourable mention in the Darwin Awards - http://www.darwinawards.com/ (joke !!). Paddy. Kirk McLoren wrote: Greetings Mr. O'Reilly The 22ns you refer to is switching time of the output chip. What would be meaningful is response time from an input to the port and the corresponding output after processing time. Of course all of it will be very quick compared to the response time of a heater. I think what is being neglected in this discussion is emphasis on the ability to measure several things and graph them and store the records for later use. Transducers are a fascinating study and the heart of interfacing digital computers to the physical world. Don't forget backup failsafes. Any accidents in this fledgling enterprise will be blown all out of proportion to the public. Home processing could be banned for example. The people that own petroleum don't want competition. Kirk --- Paddy O'Reilly [EMAIL PROTECTED] wrote: Hi, I've been thinking about using old PCs to do exactly this job for ages and for work I've used LabWindows to drive the parallel port for a host of stuff. I've been looking at using plain old DOS6.22 and freeware TurboC for control. Most parallel ports are bi-directional (well on any PC that still works), TurboC can be quite compact and when you run it under DOS there are no crazy Windows traps to fall into. I tested the PC port of an old 90MHz Pentium and I think I got 22ns switching rates from it. However, I haven't managed to get the time or useful purpose for any of my ideas yet but I'd be delighted to give you as much info as I have on controlling parallel ports and my limited knowledge of Turbo C. Paddy. . __ Do you Yahoo!? Yahoo! Mail - Find what you need with new enhanced search. http://info.mail.yahoo.com/mail_250 ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ The information contained in this e-mail and in any attachments is confidential and is designated solely for the attention of the intended recipient(s). If you are not an intended recipient, you must not use, disclose, copy, distribute or retain this e-mail or any part thereof. If you have received this e-mail in error, please notify the sender by return e-mail and delete all copies of this e-mail from your computer system(s). Please direct any additional queries to: [EMAIL PROTECTED] Thank You. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
Hi everyone, For those of you who are working on your process control for ethanol/methanol or biodiesel production, I was wondering about something. I hate to send anything to the land fill or scrap yard that I might be able to use later and I'm sure you feel the same way. This philosophy has caused me to become a bit of a pack rat (and dumpster diver). My basement is neatly organized with old (486 and P1) computers, motors, and other mechanical/electrical devices from dissected printers and other obsolete or broken down equipment. I was thinking of developing generic software (in C or assembler) for old computers to convert them into process controllers. For example, it might make an effective temperature controller for your still. If this works, I would take the programs and put them on a web page for download. If it's truly generic (compatible with all XX86 architecture), it will be a matter of copying the executable file to the hard drive of a computer, adding a line to the autoexec.bat file and making a harness (serial/parallel port to solid state relays and sensors). Has anyone tried this already and if so, can that person please share their experience with me and those interested in this thread? Thanks! Regards, Mike ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
A temperature controller that would not upset because of lightning or other power line disturbance and would not lose its settings with power supply failure may prove superior especially if less expensive. Thus a bimetal strip may prove best in the long run. I am in favor of data logging and alarms via computer but fool proof and ultra reliable control usually means no computer. Kirk --- Michael Redler [EMAIL PROTECTED] wrote: Hi everyone, For those of you who are working on your process control for ethanol/methanol or biodiesel production, I was wondering about something. I hate to send anything to the land fill or scrap yard that I might be able to use later and I'm sure you feel the same way. This philosophy has caused me to become a bit of a pack rat (and dumpster diver). My basement is neatly organized with old (486 and P1) computers, motors, and other mechanical/electrical devices from dissected printers and other obsolete or broken down equipment. I was thinking of developing generic software (in C or assembler) for old computers to convert them into process controllers. For example, it might make an effective temperature controller for your still. If this works, I would take the programs and put them on a web page for download. If it's truly generic (compatible with all XX86 architecture), it will be a matter of copying the executable file to the hard drive of a computer, adding a line to the autoexec.bat file and making a harness (serial/parallel port to solid state relays and sensors). Has anyone tried this already and if so, can that person please share their experience with me and those interested in this thread? Thanks! Regards, Mike ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ __ Do you Yahoo!? Yahoo! Mail - now with 250MB free storage. Learn more. http://info.mail.yahoo.com/mail_250 ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
OK Kirk. Thanks for the reply. I have a couple of follow-up questions: First, Is accuracy of your temperature set points (or other I/O) a critical issue for controlling a process? Because, a PID or Smith compensator control can give you far better control of your process than a bi-metallic strip for example. Second, I'd like to rephrase the question: Is there any way (in your opinion) that obsolete computers can be put to use for the purposes of generating alternative energy? Lastly: Can anything really be called foolproof? If I count the number of times that I have a power outage/lightning strike on my property, I still come up with a good risk assessment -- especially since set points can be stored in memory while power is down and I'm not sure if any control system aside from a purely mechanical one, would be effective during those relatively rare times that a mishap occurs. I've made all of my arguments (so far) without touching on the potential of a computer like a 486 as a platform for control and data acquisition -- all for the price of a bi-metallic strip. So, after reading your reply and agreeing with its logic, I'm still not convinced that the idea of using obsolete computers is too far off base. Mike Kirk McLoren [EMAIL PROTECTED] wrote: A temperature controller that would not upset because of lightning or other power line disturbance and would not lose its settings with power supply failure may prove superior especially if less expensive. Thus a bimetal strip may prove best in the long run. I am in favor of data logging and alarms via computer but fool proof and ultra reliable control usually means no computer. Kirk --- Michael Redler wrote: Hi everyone, For those of you who are working on your process control for ethanol/methanol or biodiesel production, I was wondering about something. I hate to send anything to the land fill or scrap yard that I might be able to use later and I'm sure you feel the same way. This philosophy has caused me to become a bit of a pack rat (and dumpster diver). My basement is neatly organized with old (486 and P1) computers, motors, and other mechanical/electrical devices from dissected printers and other obsolete or broken down equipment. I was thinking of developing generic software (in C or assembler) for old computers to convert them into process controllers. For example, it might make an effective temperature controller for your still. If this works, I would take the programs and put them on a web page for download. If it's truly generic (compatible with all XX86 architecture), it will be a matter of copying the executable file to the hard drive of a computer, adding a line to the autoexec.bat file and making a harness (serial/parallel port to solid state relays and sensors). Has anyone tried this already and if so, can that person please share their experience with me and those interested in this thread? Thanks! Regards, Mike ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ __ Do you Yahoo!? Yahoo! Mail - now with 250MB free storage. Learn more. http://info.mail.yahoo.com/mail_250 ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
Subject: Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea Hi everyone, ... I was thinking of developing generic software (in C or assembler) for old computers to convert them into process controllers. For example, it might make an effective temperature controller for your still. If this works, I would take the programs and put them on a web page for download. If it's truly generic (compatible with all XX86 architecture), it will be a matter of copying the executable file to the hard drive of a computer, adding a line to the autoexec.bat file and making a harness (serial/parallel port to solid state relays and sensors). Mike, I think you have a great idea. I do know that your choice of OS will be important. Between linux and microsoft there are a host of small, compact OSes that can be customized for specific support. I say this because depending on the level of control you are looking for (just turning off a mixer after a time limit or actually opening valves and running pumps) may be difficult to attain with a generic OS. However, I would look into the following areas for inspiration http://www.automatedaquariums.com/ http://www.brewtechlabs.com/prod01_falcon.htm http://www.employees.org/~joestone/Sbs/ http://www.controlanything.com/ When I started beer brewing I ran across some of this information. I don't brew enough beer to use any of this but its worth looking into. Let us know how you are progressing. I may be able to provide some help though I have never tried anything of this nature. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
Computers are great. I like them. But they aren't as reliable as simple physical systems. As for the delta T a bimetal can operate over it is a question of mechanical design. An electronic controller may theoretically switch over a change of a milli degree but in the real world the conductivity from the heater to the mass, the rate of heating, amount of mixing in a tank, rates of cooling etc can make for some temperature differences that are enormously larger than the sensitivity of the controller. As for upset my daughters computer lost its CMOS settings when the wrong breaker was thrown. Failed CMOS battery? Doesn't lose setup info if powered down. Doesn't lose it every time either. She also lost a satellite internet transponder due to a glitch on the powerline last year. Expensive spike that one. You will also note Windows users are warned to not use windows for critical control applications such as life support. In industry numerical controllers are widely used but critical operations have staff during operation and redundant controls if failure analysis indicates. Redundant controls and voting? That helps failure rate but it is still not perfect. I think if you size the heater so that if it fails on while unattended so that it cannot cause a fire or other danger then maybe your computer controller is an acceptable risk. Maybe include a bimetal disk cutout at 10 or 20 above highest temp ever used. Appliance clothes dryers have a backup cutout. They have to. Too many fires otherwise and those controllers are much more reliable than windoze. I think old computers are great for data logging but be damn careful when you include them in the loop for control. Always have a backup safety or you may have a situation not bargained for. Kirk --- Michael Redler [EMAIL PROTECTED] wrote: OK Kirk. Thanks for the reply. I have a couple of follow-up questions: First, Is accuracy of your temperature set points (or other I/O) a critical issue for controlling a process? Because, a PID or Smith compensator control can give you far better control of your process than a bi-metallic strip for example. Second, I'd like to rephrase the question: Is there any way (in your opinion) that obsolete computers can be put to use for the purposes of generating alternative energy? Lastly: Can anything really be called foolproof? If I count the number of times that I have a power outage/lightning strike on my property, I still come up with a good risk assessment -- especially since set points can be stored in memory while power is down and I'm not sure if any control system aside from a purely mechanical one, would be effective during those relatively rare times that a mishap occurs. I've made all of my arguments (so far) without touching on the potential of a computer like a 486 as a platform for control and data acquisition -- all for the price of a bi-metallic strip. So, after reading your reply and agreeing with its logic, I'm still not convinced that the idea of using obsolete computers is too far off base. Mike Kirk McLoren [EMAIL PROTECTED] wrote: A temperature controller that would not upset because of lightning or other power line disturbance and would not lose its settings with power supply failure may prove superior especially if less expensive. Thus a bimetal strip may prove best in the long run. I am in favor of data logging and alarms via computer but fool proof and ultra reliable control usually means no computer. Kirk --- Michael Redler wrote: Hi everyone, For those of you who are working on your process control for ethanol/methanol or biodiesel production, I was wondering about something. I hate to send anything to the land fill or scrap yard that I might be able to use later and I'm sure you feel the same way. This philosophy has caused me to become a bit of a pack rat (and dumpster diver). My basement is neatly organized with old (486 and P1) computers, motors, and other mechanical/electrical devices from dissected printers and other obsolete or broken down equipment. I was thinking of developing generic software (in C or assembler) for old computers to convert them into process controllers. For example, it might make an effective temperature controller for your still. If this works, I would take the programs and put them on a web page for download. If it's truly generic (compatible with all XX86 architecture), it will be a matter of copying the executable file to the hard drive of a computer, adding a line to the autoexec.bat file and making a harness (serial/parallel port to solid state relays and sensors). Has anyone tried this already and if so, can that person please share their experience with me and those interested in this thread? Thanks! Regards, Mike ___ Biofuel mailing list
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
I've been thinking about using old PCs to do exactly this job for ages and for work I've used LabWindows to drive the parallel port for a host of stuff. I've been looking at using plain old DOS6.22 and freeware TurboC for control. Most parallel ports are bi-directional (well on any PC that still works), TurboC can be quite compact and when you run it under DOS there are no crazy Windows traps to fall into. I tested the PC port of an old 90MHz Pentium and I think I got 22ns switching rates from it. However, I haven't managed to get the time or useful purpose for any of my ideas yet but I'd be delighted to give you as much info as I have on controlling parallel ports and my limited knowledge of Turbo C. Paddy. DHAJOGLO wrote: Subject: Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea Hi everyone, ... I was thinking of developing generic software (in C or assembler) for old computers to convert them into process controllers. For example, it might make an effective temperature controller for your still. If this works, I would take the programs and put them on a web page for download. If it's truly generic (compatible with all XX86 architecture), it will be a matter of copying the executable file to the hard drive of a computer, adding a line to the autoexec.bat file and making a harness (serial/parallel port to solid state relays and sensors). Mike, I think you have a great idea. I do know that your choice of OS will be important. Between linux and microsoft there are a host of small, compact OSes that can be customized for specific support. I say this because depending on the level of control you are looking for (just turning off a mixer after a time limit or actually opening valves and running pumps) may be difficult to attain with a generic OS. However, I would look into the following areas for inspiration http://www.automatedaquariums.com/ http://www.brewtechlabs.com/prod01_falcon.htm http://www.employees.org/~joestone/Sbs/ http://www.controlanything.com/ When I started beer brewing I ran across some of this information. I don't brew enough beer to use any of this but its worth looking into. Let us know how you are progressing. I may be able to provide some help though I have never tried anything of this nature. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ The information contained in this e-mail and in any attachments is confidential and is designated solely for the attention of the intended recipient(s). If you are not an intended recipient, you must not use, disclose, copy, distribute or retain this e-mail or any part thereof. If you have received this e-mail in error, please notify the sender by return e-mail and delete all copies of this e-mail from your computer system(s). Please direct any additional queries to: [EMAIL PROTECTED] Thank You. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
always a rush of adrenalin when you run your own program and wait in anticipation to see if your programming skills don't blow up your basement ;o) Kirk McLoren wrote: Computers are great. I like them. But they aren't as reliable as simple physical systems. As for the delta T a bimetal can operate over it is a question of mechanical design. An electronic controller may theoretically switch over a change of a milli degree but in the real world the conductivity from the heater to the mass, the rate of heating, amount of mixing in a tank, rates of cooling etc can make for some temperature differences that are enormously larger than the sensitivity of the controller. As for upset my daughters computer lost its CMOS settings when the wrong breaker was thrown. Failed CMOS battery? Doesn't lose setup info if powered down. Doesn't lose it every time either. She also lost a satellite internet transponder due to a glitch on the powerline last year. Expensive spike that one. You will also note Windows users are warned to not use windows for critical control applications such as life support. In industry numerical controllers are widely used but critical operations have staff during operation and redundant controls if failure analysis indicates. Redundant controls and voting? That helps failure rate but it is still not perfect. I think if you size the heater so that if it fails on while unattended so that it cannot cause a fire or other danger then maybe your computer controller is an acceptable risk. Maybe include a bimetal disk cutout at 10 or 20 above highest temp ever used. Appliance clothes dryers have a backup cutout. They have to. Too many fires otherwise and those controllers are much more reliable than windoze. I think old computers are great for data logging but be damn careful when you include them in the loop for control. Always have a backup safety or you may have a situation not bargained for. Kirk --- Michael Redler [EMAIL PROTECTED] wrote: OK Kirk. Thanks for the reply. I have a couple of follow-up questions: First, Is accuracy of your temperature set points (or other I/O) a critical issue for controlling a process? Because, a PID or Smith compensator control can give you far better control of your process than a bi-metallic strip for example. Second, I'd like to rephrase the question: Is there any way (in your opinion) that obsolete computers can be put to use for the purposes of generating alternative energy? Lastly: Can anything really be called foolproof? If I count the number of times that I have a power outage/lightning strike on my property, I still come up with a good risk assessment -- especially since set points can be stored in memory while power is down and I'm not sure if any control system aside from a purely mechanical one, would be effective during those relatively rare times that a mishap occurs. I've made all of my arguments (so far) without touching on the potential of a computer like a 486 as a platform for control and data acquisition -- all for the price of a bi-metallic strip. So, after reading your reply and agreeing with its logic, I'm still not convinced that the idea of using obsolete computers is too far off base. Mike Kirk McLoren [EMAIL PROTECTED] wrote: A temperature controller that would not upset because of lightning or other power line disturbance and would not lose its settings with power supply failure may prove superior especially if less expensive. Thus a bimetal strip may prove best in the long run. I am in favor of data logging and alarms via computer but fool proof and ultra reliable control usually means no computer. Kirk --- Michael Redler wrote: Hi everyone, For those of you who are working on your process control for ethanol/methanol or biodiesel production, I was wondering about something. I hate to send anything to the land fill or scrap yard that I might be able to use later and I'm sure you feel the same way. This philosophy has caused me to become a bit of a pack rat (and dumpster diver). My basement is neatly organized with old (486 and P1) computers, motors, and other mechanical/electrical devices from dissected printers and other obsolete or broken down equipment. I was thinking of developing generic software (in C or assembler) for old computers to convert them into process controllers. For example, it might make an effective temperature controller for your still. If this works, I would take the programs and put them on a web page for download. If it's truly generic (compatible with all XX86 architecture), it will be a matter of copying the executable file to the hard drive of a computer, adding a line to the autoexec.bat file and making a harness (serial/parallel port to solid state relays and sensors). Has anyone tried this already and if so, can that person please share their experience
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
Kirk, Well, again, I don't think your logic is off base -- especially when it comes to redundancy in control systems. There are ways to approach each of the situations you described in your reply. I worked as a control engineer for a few years and wrote computer logic (typically 0 to 20 mA output) to control plastic processing equipment with thousand horsepower motors and precision temperature controls that ran 24/7. From my experience, there is an abundance of evidence in industry that shows the reliability of computer controls when done carefully. But, if you are not so convinced, that's OK too. I think at this point in our exchange, we can agree to disagree. I think that you have already considered the options and made a decision about which way to control your process. There is nobody more knowledgeable about your own process requirements than you. :-) Mike Kirk McLoren [EMAIL PROTECTED] wrote: Computers are great. I like them. But they aren't as reliable as simple physical systems. As for the delta T a bimetal can operate over it is a question of mechanical design. An electronic controller may theoretically switch over a change of a milli degree but in the real world the conductivity from the heater to the mass, the rate of heating, amount of mixing in a tank, rates of cooling etc can make for some temperature differences that are enormously larger than the sensitivity of the controller. As for upset my daughters computer lost its CMOS settings when the wrong breaker was thrown. Failed CMOS battery? Doesn't lose setup info if powered down. Doesn't lose it every time either. She also lost a satellite internet transponder due to a glitch on the powerline last year. Expensive spike that one. You will also note Windows users are warned to not use windows for critical control applications such as life support. In industry numerical controllers are widely used but critical operations have staff during operation and redundant controls if failure analysis indicates. Redundant controls and voting? That helps failure rate but it is still not perfect. I think if you size the heater so that if it fails on while unattended so that it cannot cause a fire or other danger then maybe your computer controller is an acceptable risk. Maybe include a bimetal disk cutout at 10 or 20 above highest temp ever used. Appliance clothes dryers have a backup cutout. They have to. Too many fires otherwise and those controllers are much more reliable than windoze. I think old computers are great for data logging but be damn careful when you include them in the loop for control. Always have a backup safety or you may have a situation not bargained for. Kirk --- Michael Redler wrote: OK Kirk. Thanks for the reply. I have a couple of follow-up questions: First, Is accuracy of your temperature set points (or other I/O) a critical issue for controlling a process? Because, a PID or Smith compensator control can give you far better control of your process than a bi-metallic strip for example. Second, I'd like to rephrase the question: Is there any way (in your opinion) that obsolete computers can be put to use for the purposes of generating alternative energy? Lastly: Can anything really be called foolproof? If I count the number of times that I have a power outage/lightning strike on my property, I still come up with a good risk assessment -- especially since set points can be stored in memory while power is down and I'm not sure if any control system aside from a purely mechanical one, would be effective during those relatively rare times that a mishap occurs. I've made all of my arguments (so far) without touching on the potential of a computer like a 486 as a platform for control and data acquisition -- all for the price of a bi-metallic strip. So, after reading your reply and agreeing with its logic, I'm still not convinced that the idea of using obsolete computers is too far off base. Mike Kirk McLoren wrote: A temperature controller that would not upset because of lightning or other power line disturbance and would not lose its settings with power supply failure may prove superior especially if less expensive. Thus a bimetal strip may prove best in the long run. I am in favor of data logging and alarms via computer but fool proof and ultra reliable control usually means no computer. Kirk --- Michael Redler wrote: Hi everyone, For those of you who are working on your process control for ethanol/methanol or biodiesel production, I was wondering about something. I hate to send anything to the land fill or scrap yard that I might be able to use later and I'm sure you feel the same way. This philosophy has caused me to become a bit of a pack rat (and dumpster diver). My basement is neatly organized with old (486 and P1) computers, motors, and other mechanical/electrical devices from dissected
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
Right on! I knew that I couldn't possibly be the first person to think of this. I just didn't know where to look. I will definitely keep you informed of any progress. Thanks. Mike DHAJOGLO [EMAIL PROTECTED] wrote: Subject: Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea Hi everyone, ... I was thinking of developing generic software (in C or assembler) for old computers to convert them into process controllers. For example, it might make an effective temperature controller for your still. If this works, I would take the programs and put them on a web page for download. If it's truly generic (compatible with all XX86 architecture), it will be a matter of copying the executable file to the hard drive of a computer, adding a line to the autoexec.bat file and making a harness (serial/parallel port to solid state relays and sensors). Mike, I think you have a great idea. I do know that your choice of OS will be important. Between linux and microsoft there are a host of small, compact OSes that can be customized for specific support. I say this because depending on the level of control you are looking for (just turning off a mixer after a time limit or actually opening valves and running pumps) may be difficult to attain with a generic OS. However, I would look into the following areas for inspiration http://www.automatedaquariums.com/ http://www.brewtechlabs.com/prod01_falcon.htm http://www.employees.org/~joestone/Sbs/ http://www.controlanything.com/ When I started beer brewing I ran across some of this information. I don't brew enough beer to use any of this but its worth looking into. Let us know how you are progressing. I may be able to provide some help though I have never tried anything of this nature. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
Thanks Paddy! Ah yes...time. It's funny that way. I remember being in high school and complaining how I didn't have any money. It would be nice to have both some day. :-) Mike Paddy O'Reilly [EMAIL PROTECTED] wrote: Hi, I've been thinking about using old PCs to do exactly this job for ages and for work I've used LabWindows to drive the parallel port for a host of stuff. I've been looking at using plain old DOS6.22 and freeware TurboC for control. Most parallel ports are bi-directional (well on any PC that still works), TurboC can be quite compact and when you run it under DOS there are no crazy Windows traps to fall into. I tested the PC port of an old 90MHz Pentium and I think I got 22ns switching rates from it. However, I haven't managed to get the time or useful purpose for any of my ideas yet but I'd be delighted to give you as much info as I have on controlling parallel ports and my limited knowledge of Turbo C. Paddy. DHAJOGLO wrote: Subject: Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea Hi everyone, ... I was thinking of developing generic software (in C or assembler) for old computers to convert them into process controllers. For example, it might make an effective temperature controller for your still. If this works, I would take the programs and put them on a web page for download. If it's truly generic (compatible with all XX86 architecture), it will be a matter of copying the executable file to the hard drive of a computer, adding a line to the autoexec.bat file and making a harness (serial/parallel port to solid state relays and sensors). Mike, I think you have a great idea. I do know that your choice of OS will be important. Between linux and microsoft there are a host of small, compact OSes that can be customized for specific support. I say this because depending on the level of control you are looking for (just turning off a mixer after a time limit or actually opening valves and running pumps) may be difficult to attain with a generic OS. However, I would look into the following areas for inspiration http://www.automatedaquariums.com/ http://www.brewtechlabs.com/prod01_falcon.htm http://www.employees.org/~joestone/Sbs/ http://www.controlanything.com/ When I started beer brewing I ran across some of this information. I don't brew enough beer to use any of this but its worth looking into. Let us know how you are progressing. I may be able to provide some help though I have never tried anything of this nature. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ The information contained in this e-mail and in any attachments is confidential and is designated solely for the attention of the intended recipient(s). If you are not an intended recipient, you must not use, disclose, copy, distribute or retain this e-mail or any part thereof. If you have received this e-mail in error, please notify the sender by return e-mail and delete all copies of this e-mail from your computer system(s). Please direct any additional queries to: [EMAIL PROTECTED] Thank You. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea
Hi, Have you thought of using Linux for this use?? There are no problems with the thought police, there are optimised distros made for these types of jobs, inc real-time o/s's. Remember: no virus problems in Linux (albeit yet!) regards Doug On Wednesday 23 February 2005 5:03, Michael Redler wrote: Thanks Paddy! Ah yes...time. It's funny that way. I remember being in high school and complaining how I didn't have any money. It would be nice to have both some day. :-) Mike Paddy O'Reilly [EMAIL PROTECTED] wrote: Hi, I've been thinking about using old PCs to do exactly this job for ages and for work I've used LabWindows to drive the parallel port for a host of stuff. I've been looking at using plain old DOS6.22 and freeware TurboC for control. Most parallel ports are bi-directional (well on any PC that still works), TurboC can be quite compact and when you run it under DOS there are no crazy Windows traps to fall into. I tested the PC port of an old 90MHz Pentium and I think I got 22ns switching rates from it. However, I haven't managed to get the time or useful purpose for any of my ideas yet but I'd be delighted to give you as much info as I have on controlling parallel ports and my limited knowledge of Turbo C. Paddy. DHAJOGLO wrote: Subject: Re: [Biofuel] Attn. Pack Rats -- (maybe) A cheap Process Control Idea Hi everyone, ... I was thinking of developing generic software (in C or assembler) for old computers to convert them into process controllers. For example, it might make an effective temperature controller for your still. If this works, I would take the programs and put them on a web page for download. If it's truly generic (compatible with all XX86 architecture), it will be a matter of copying the executable file to the hard drive of a computer, adding a line to the autoexec.bat file and making a harness (serial/parallel port to solid state relays and sensors). Mike, I think you have a great idea. I do know that your choice of OS will be important. Between linux and microsoft there are a host of small, compact OSes that can be customized for specific support. I say this because depending on the level of control you are looking for (just turning off a mixer after a time limit or actually opening valves and running pumps) may be difficult to attain with a generic OS. However, I would look into the following areas for inspiration http://www.automatedaquariums.com/ http://www.brewtechlabs.com/prod01_falcon.htm http://www.employees.org/~joestone/Sbs/ http://www.controlanything.com/ When I started beer brewing I ran across some of this information. I don't brew enough beer to use any of this but its worth looking into. Let us know how you are progressing. I may be able to provide some help though I have never tried anything of this nature. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ The information contained in this e-mail and in any attachments is confidential and is designated solely for the attention of the intended recipient(s). If you are not an intended recipient, you must not use, disclose, copy, distribute or retain this e-mail or any part thereof. If you have received this e-mail in error, please notify the sender by return e-mail and delete all copies of this e-mail from your computer system(s). Please direct any additional queries to: [EMAIL PROTECTED] Thank You. ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/ ___ Biofuel mailing list [EMAIL PROTECTED] http://wwia.org/mailman/listinfo.cgi/biofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuel archives at Infoarchive.net (searchable): http://infoarchive.net/sgroup/biofuel/
