- OT-basement venting help please - 5 Updates
- Kind of a generic electrolytic cap question - 12 Updates
| "pfjw@aol.com" <peterwieck33@gmail.com>: Nov 15 12:02PM -0800 You need to brush up on your Sensible Heat and Latent Heat definitions, and how they affect temperature vs. humidity vs. comfort. Dryer air is generally perceived as warmer than wetter air, except at the extremes (sauna vs. steam bath), and why it is that Dubai is insufferable, whereas Phoenix is more tolerable at the same actual temperature. That is Part A. Now, a standard dehumidifier cools by refrigerating a coil, then drawing air across it, thereby cooling it and dehumidifying it, then using the waste heat from the cooling process to reheat the air so that it comes out at more-or-less the same temperature it started at, only dryer. Sure, there will be some heat-gain from the motor(s) and condensate pump, if used, but that gain will be relatively tiny, with much of it being absorbed into the condensate if the unit is well designed. That is Part B. Being as you are in Florida, and let's make a leap that you are on/near the coast or other wetlands, you are in a climate much closer to Dubai than Phoenix. You are running your AC to dehumidify not to cool - which is perfectly valid, and why it is that large commercial and institutional systems use reheat coils, or local VAV boxes or Phoenix valves. They maintain a constant discharge temperature, typically running about 55F discharge air from the central AHU, reheating at the VAV to a set temperature. A VAV gives constant temperature, at a variable volume. A Phoenix Valve gives constant temperature and flow - useful in classrooms and labs where air-changes must meet some standard. Hope that clarifies. Peter Wieck Melrose Park, PA |
| "pfjw@aol.com" <peterwieck33@gmail.com>: Nov 15 12:04PM -0800 Oh, and why it is that I advised the OP to invest in a condensate pump - to pull the warmed water out of the room. This eliminates re-evaporation as well as the heat it absorbs. It is all part of the process. Peter Wieck Melrose Park, PA |
| amdx <nojunk@knology.net>: Nov 16 07:35AM -0600 > You need to brush up on your Sensible Heat and Latent Heat definitions, and how they affect temperature vs. humidity vs. comfort. Dryer air is generally perceived as warmer than wetter air, except at the extremes (sauna vs. steam bath), and why it is that Dubai is insufferable, whereas Phoenix is more tolerable at the same actual temperature. That is Part A. So you agree with me, dry air is more comfortable, with your qualification that I must be at an extreme. > Now, a standard dehumidifier cools by refrigerating a coil, then drawing air across it, thereby cooling it and dehumidifying it, then using the waste heat from the cooling process to reheat the air so that it comes out at more-or-less the same temperature it started at, only dryer. Sure, there will be some heat-gain from the motor(s) and condensate pump, if used, but that gain will be relatively tiny, with much of it being absorbed into the condensate if the unit is well designed. That is Part B. You forgot the heat that was removed from in the condensate container, or pumped down the drain. That also gets put into the room. > Being as you are in Florida, and let's make a leap that you are on/near the coast or other wetlands, you are in a climate much closer to Dubai than Phoenix. You are running your AC to dehumidify not to cool - which is perfectly valid, Clearly it's both, but as I said, if I can get the humidity 40 or below, I can raise the temp about 4*F and still be just as comfortable. You are missing the human body in all your equations. To cool you need to remove perspiration by evaporation, low humidity aids that and makes for comfort. We keep the thermostat at 78*f in summer, there are low humidity days when the air conditioning runs to keep temp down to 78*F, but the humidity gets low and I get cold, to where I need to put more clothes on. and why it is that large commercial and institutional systems use reheat coils, or local VAV boxes or Phoenix valves. They maintain a constant discharge temperature, typically running about 55F discharge air from the central AHU, reheating at the VAV to a set temperature. A VAV gives constant temperature, at a variable volume. A Phoenix Valve gives constant temperature and flow - useful in classrooms and labs where air-changes must meet some standard. |
| Tim R <timothy42b@aol.com>: Nov 16 06:45AM -0800 A dehumidifier should be heat neutral as you say. I'm not so sure about the process. A phase change is involved, when water goes from gas to liquid it has to dump all that phase change energy. I use a dehumidifier in the basement. If you figure out how to make one last more than 2 years let me know. |
| Ralph Mowery <rmowery28146@earthlink.net>: Nov 16 11:16AM -0500 In article <3172fcc8-cfa4-4313-ae22-b23bc9d8300e@googlegroups.com>, timothy42b@aol.com says... > A dehumidifier should be heat neutral as you say. > I?m not so sure about the process. A phase change is involved, when water goes from gas to liquid it has to dump all that phase change energy. > I use a dehumidifier in the basement. If you figure out how to make one last more than 2 years let me know. The dehumidifiers in homes do produce some heat from the motors. Not much, but some. Then if you have to empty the water by hand, you are not loosing heat by the water to ammount to anyting. Many people do not get very many years out of their dehumidifires. Looks like they should as they are nothing much more than a refrigerator with an open door or even an airconditioner. I have not thought about it , but I wonder if you put a window AC in a room and a drain bucket under it if it would not be just as good as the dehumidifier and last longer. I think the newer ones do use the splash from the condenced water to help cool the coils. |
| John Robertson <spam@flippers.com>: Nov 15 08:42AM -0800 On 2019/11/15 5:26 a.m., John-Del wrote: >>> circuit on many modern circuit boards is a waste of time. >> Why so? > Too many circuits these days use a small value SMD multi layer chip capacitor bypassing an electrolytic. These chip caps have ESR figures as low or lower than most electrolytics you're likely to run across despite being small value caps. Except this machine is from 1982 (paper tape readers, etc.) - so any electros are primary smoothing ones for Vcc. http://cncmanual.com/download/1647/ John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| Chuck <ch@dejanews.net>: Nov 15 11:58AM -0600 On Fri, 15 Nov 2019 08:42:37 -0800, John Robertson <spam@flippers.com> wrote: >electros are primary smoothing ones for Vcc. >http://cncmanual.com/download/1647/ >John :-#)# Some Grass Valley products from the early 80s had electrolytics that would open but the surrounding circuitry would cause an ESR meter to read very low ESR. Once the electrolytic was pulled, it would test bad. |
| "Ron D." <ron.dozier@gmail.com>: Nov 15 10:56AM -0800 The EProms can cause issues when they age. From my days of programming the 2716's. My programmer was semi-manual and it was really sensitive to the the programming voltage. An EEprom may not have been erased completely. Do inspect the board for bad solder joints. Freeze spray can sometimes help make equipment fail or work. On a non-powered board, it can help highlight a bad solder joint. |
| John Robertson <spam@flippers.com>: Nov 15 11:27AM -0800 On 2019/11/15 10:56 a.m., Ron D. wrote: > An EEprom may not have been erased completely. > Do inspect the board for bad solder joints. > Freeze spray can sometimes help make equipment fail or work. On a non-powered board, it can help highlight a bad solder joint. My Xeltek 610P programmer has a feature where it will test EPROMs at +/- 10% of the voltage to help weed out iffy burns or EPROMs. Recently I had some EPROMs I was verifying and they failed the over-voltage test - so I reprogrammed them (not erased, just hit them with the programmer burn process) and then they tested just fine. I assume I recharged the gates so all was then well. John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| etpm@whidbey.com: Nov 15 12:01PM -0800 On Fri, 15 Nov 2019 11:27:05 -0800, John Robertson <spam@flippers.com> wrote: >with the programmer burn process) and then they tested just fine. I >assume I recharged the gates so all was then well. >John :-#)# I will need to erase the EPROMs before they get new programs. My wife has a UV light source she uses for curing some sort of fingernail coating for artificial nails. I'm hoping it will work OK. The programmer I am buying is the MCUmall Electronics model GQ-4x4. I called them and they said programmer software verifies the info downloaded from the EPROM and then once again verifies the uploaded info. Eric |
| John Robertson <spam@flippers.com>: Nov 15 12:38PM -0800 > downloaded from the EPROM and then once again verifies the uploaded > info. > Eric I would HIGHLY recommend that you keep the original EPROMs and get some good 2716s to burn and a few spares... Please do not erase your originals! John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| etpm@whidbey.com: Nov 15 12:47PM -0800 On Fri, 15 Nov 2019 12:38:19 -0800, John Robertson <spam@flippers.com> wrote: >good 2716s to burn and a few spares... >Please do not erase your originals! >John :-#)# I will NOT be erasing the originals. They are, as near as I can tell, not available from any soyrce. I have looked for a long time on eBay in the hope that someone scrapping a machine will have some. But the machines, while similar, are never the same. I'm even afriad to copy them. That's why I am going to practice on some others first. Eric |
| John Robertson <spam@flippers.com>: Nov 15 01:48PM -0800 > machines, while similar, are never the same. I'm even afriad to copy > them. That's why I am going to practice on some others first. > Eric Reading is pretty safe, however I would recommend you contact MCUmall and make sure that the READ process for pin 21 is done at 5VDC and not at the programming voltage which is 21VDC. You can verify this with a voltmeter by simply not having any chip in the socket and then do a read while monitoring socket pin 21 (ad common at pin 12) to make sure the voltage is 5VDC. It would not hurt to verify that pin 24, again relative to pin 12 - is also 5VDC. Lastly, for the paranoid folks, I would also check pin 20 and 18 to make sure they are never higher than 5VDC. I am not saying the MCUmall programmer is bad, I'm just pointing out how I would check any programmer that I am trusting irreplaceable EPROMs to! If you have a scope so much the better to test the programmer READ voltages at the various pins! As you say you only have the one set of EPROMs and your equipment would be worthless if any are damaged by the programmer! Does this machine have an 8-bit CPU such as Z80, 68XX, 6502, etc? If someone lives near you and has a Fluke 9010 with the appropriate pod then they could extract the data from the EPROMs at no risk to them. They would also need an RS-232 port on the Fluke to grab the data... I can do this in my shop, but I suspect we are not very close - I'm in Vancouver (Burnaby, but no one knows that city), Canada area... John -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| etpm@whidbey.com: Nov 15 03:57PM -0800 On Fri, 15 Nov 2019 13:48:51 -0800, John Robertson <spam@flippers.com> wrote: >can do this in my shop, but I suspect we are not very close - I'm in >Vancouver (Burnaby, but no one knows that city), Canada area... >John It's a Fanuc control and as far as I know the control is completely Fanuc. I don't know anyone who has s Fluke 9010 and even though I know where Burnaby is it is still a bit of a drive from the south end of Whidbey Island. I do have other 2516 EPROMs that are useless to me that I am going to use to test the reader/programmer. The tech support guy did say that 2516 devices may not program properly but that they can be read just fine. Nevertheless I will take your advice. I can use my TEK 465B scope to check the voltages. And I read either here or in an email from the tech support folks that the TI 2516 devices are the same as the 2716 devices and I know that at least one EPROM is a TI 2516. There is a mix of devices because it seems that at least two EPROMs are common to almost every board from Miyano lathes and the other 4 on the one board are the ones I need to copy. So as I buy old boards I get, now and then, copies of the two common types. So these will be tested first along with some other 2516 devices I have from another Fanuc control. I really appreciate all the advice I get here and especially the EPROM advice I am getting recently. It really makes me feel better about repairing this machine. Speaking of this lathe, I know people who would say just replace the machine or at least the control. But I have done a complete control replacement before and it is not trivial. And Fanuc controls are usually very robust. It is just this one board that is giving me problems and I can't see how the machine itself could be damaging this particular board. I could just replace the machine completely but this is very expensive and this particular machine is just not getting enough work at this time to justify at least 60 grand to replace it. The lathe itself is, the mechanics and the servos, are in great shape. I can hold .0001" without any problems. All day. Even though the top spindle speed is only 5000 RPM most of the work I do can't be done at higher RPM because of the diameter and material of the work. Eric |
| John Robertson <spam@flippers.com>: Nov 15 04:45PM -0800 > the top spindle speed is only 5000 RPM most of the work I do can't be > done at higher RPM because of the diameter and material of the work. > Eric Whidbey Island is just a day trip to Vancouver/Burnaby. I'd be happy to archive your EPROMs and burn you up a set of spares if you can't sort it out... I think you are neighbour to my friend the ex-basketball player who loves pinball, if you know who I am speaking of, tell him I said "Hi!". John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| stratus46@yahoo.com: Nov 16 02:05AM -0800 On Friday, November 15, 2019 at 5:30:14 AM UTC-8, John-Del wrote: > > You may want to test the new ones before you put them in. > If you know the board *will* be fixed and put back in service, then yes, by all means replace them. But if I pull an electro during testing and it's good, I put it back and continue working on the board. No sense changing good caps on a board that may have to be replaced, like OP is dealing with. > Lots of these industrial boards use custom ICs, ICs and semis that have been intentionally defaced, and processor ICs for which there is just no data. Sometimes you just have to replace a board. 'lytic caps go bad eventually. After removing the caps for testing you've already run the risk of damaging the board. Why put the old ones back? In broadcast gear small value caps are the most common failures. I've replaced thousands of 100uF 25 V caps. Unit price 32 cents, 1000 for $83. Buy in bulk and replace in bulk. It costs less than testing and re-installing. G² |
| Ralph Mowery <rmowery28146@earthlink.net>: Nov 16 11:09AM -0500 In article <ce8fc86d-344f-466a-a13e-8f5ca0ccfd05@googlegroups.com>, stratus46@yahoo.com says... > 'lytic caps go bad eventually. After removing the caps for testing you've already run the risk of damaging the board. Why put the old ones back? In broadcast gear small value caps are the most common failures. I've replaced thousands of 100uF 25 V caps. Unit price 32 cents, 1000 for $83. Buy in bulk and replace in bulk. It costs less than testing and re-installing. > G Right, at the small cost of the capacitors, it is foolish to put backin an old one even if the board may have other problems and not used. Now if it was a $ 10 or even maybe a $ 5 part it may be worth putting the old part back on. At the rate capacitors fail, the one that tested good may go bad much sooner than a new one. Then you have to do it all over again. It takes often takes more labor time and effort to test than to just put in a new one. Like where I work, a man from the factory came in to repair a 480 volt 3 phase 200 HP motor speed control. He found 2 bad dioides that were rated at something like 200 amps. I asked him to replace the 3 rd one. He told me those things cost arond $ 200 each. I told him that with 2 bad it may have weakened the 3 rd one. With the machinery costing the company over $ 1000 per hour for down time, and the cost of getting him back in the plant, I am willing to pay $ 200 for insurance and piece of mind. That old diode may pop in a day or 10 years, but I know that I have done my best to make sure the machine keeps on running for minimal extra cost. |
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