On Sunday, 29 May 2022 21:03:27 EDT Chris Albertson wrote: > So basically you have a hammer, so the task is to make every project > look like a nail, so you can use the one tool you have, But then you > end up using a A/D converter and FPGA and a Linux PC with a real-time > operating system to run an air compressor motor.
You make it sound far more complex > But all you really need is a comparator to compare the current pressure > to the desired, and close contact or not. But since its 5 of those $6.95 compressors from mpja.com, mounted on a 5mm thick printed plate, suspended on shock mounts borrowed from a defunct soldering stations hot air puffer, that combined have a run current just over an amp, and have only a simple, low volume manifold for pressure storage, no big tank to absorb the pulses of an on off switch, why not adjust a 4 kilohertz pwm to run them only fast enough to get the needed pressure, which is in the 2 to 4 psi range? 20 watts worth of 12 volts max, compared to burning up a 2hp shop compressor, which at the air volume needed is running well over 50% of the time. I can't even hear these running over the fan in the vfd, conpared to the total lack of intake muffler on the shop compressor making so much noise I can't hear myself think? The linux pc is already running the rest of the machine at a 2 kilohertz servo thread, something that i5 does w/o even raising the cpu temps. The pwm is on-off, but at 4 kilohertz, smack in the middle of the carhart notches in my hearing caused by wearing out the first 2 barrels on "old meat in the pot" before I bought my first earmuffs 50 years ago. Now its on its 5th barrel, but in deference to the age of the shoulder, the last one I installed 3 years ago is now chambered for 6.5 Creedmoor instead of the series of Ackley-06's its been wearing for 60 years. Noticably less kick. Why not use some of its cpu cycles and do it right? Running slower they'll last longer, and will probably outlast me at no more hours a month than I run it. Unless this vise screw project I'm in the middle of keeps me and it busy. If it works, I intend to advertize it in Fine Woodworking. Gives me something to do and keeps me out of the bars. At 87, my pacemakers battery is projected to run me till about 93, if Gates and Fauci haven't figured out how to kill me first. Or the TAVR aortic valve in my heart fails. It's running at 100% flow at the 2 year mark. I'm like a local judge whose long gone now, standing in the aisle behind the register row at walmart looking around for his wife not long after the local walmart opened, "I'd get me another woman but it takes so long to train them". Les was always good for a chuckle. [...] Take care and stay well now, both you and yours, Chris. Cheers, Gene Heskett. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
