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MoominPapa

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Everything posted by MoominPapa

  1. For sink outlets, it's normal to consider the flooding height as the height of the sink rim, not the hole in the side. A surveyor being very cautious my insist that hoses are double clamped before allowing this. I'd suggest finding another broker and another surveyor. Bilge pump outlets can suffer from syphoning, so the easiest solution may be to do as the surveyor suggests, MP.
  2. 13Kg propane last week cost £37.50. The news on the street is that after a couple of months of relatively normal conditions, availability has gone TU again, and there's a major shortage. Not a good time for us to lose a substantial fraction of a cylinder-full over board when the union of the regulator end of a pigtail cracked and the hose more-or-less fell off.
  3. They aren't on the SIM card: those have very little memory. They MIGHT be on an SD-card if you have one installed and configured the phone to use it. They might be backed up in The Cloud if you use Google Photos or similar. MP.
  4. It's the line to Ellesmere Port. Probably still running on steam. MP.
  5. Just speculation. 132A is the railway crossing and the railway crosses the canal at high level and a significant skew, so that the railway embankment is almost parallel to the canal and approaches to zero distance from it at the start of the bridge. A tree on the railway embankment which went over towards the canal could end up with the crown of the tree blocking the canal, but a large and heavy trunk above that going up the embankment and supported only by the crown. You really wouldn't want to remove the crown and have the now-unsupported trunk descend onto your head. MP.
  6. From the latest stoppage update: Dunno if that helps..... MP.
  7. But if the outlet from the calorifier and the outlet from the heater are connected together, then the outlet of the heater will be pressurised. There's nothing in the heater to stop reverse flow, so the inlet to the heater will be pressurised too, as will the outlet side of the isolator, where the arrow is pointing. The arrow is there to tell you not to pressurise the outlet side when the isolator is off. https://www.ebay.co.uk/itm/271605613643?hash=item3f3cf4c44b:g:LwsAAOxyA7tSYOui is what you need. MP.
  8. I'll take a guess that they're directional, and not intended to have high pressure on the side the arrow is pointing _towards_ when closed. I'll take a further guess that you have a calorifier which you use when the gas heater is isolated, so that there is pressure on that side of the valve, when closed, from the pressure in the calorifier and hot pipes coming back through the heat-exchanger. If I guessed right, I use half-turn butterfly-handle valves for the same function and have had no such problems. MP.
  9. I don't know. I just tried to find a cross-section diagram of one to see if they do have a stack of junctions and failed miserably. MP.
  10. Possibly, if I could have determined which contact was the problem. Given that the chassis is riveted aluminium there's dissimilar metal problems and corrosion to take into account too, adding a wire was the first thing I tried and it worked so I didn't explore other options. MP. I've not. If they're 20v open circuit there must be quite a stack on junctions in there, individual thermocouple junctions are in the mV/Celsius range. MP.
  11. We had similar problems with a Spinflo grill/oven combo, which is basically the same stuff and made by the same people. The problem turned out to be that the design relied of the cooker chassis to provide the return current path from the thermocouple to the gas valve. As the thing aged, the connections between the thermocouple and the chassis, the valve and the chassis, and the various bits of the chassis, increased in resistance. The voltage generated by the thermocouple is tiny, and it doesn't take much resistance to decrease the current below that needed to hold in the solenoid valve. The fix was to run a wire from the mounting nut of the thermocouple to a mounting screw of the valve, which worked instantly. Be careful to use either uninsulated wire or wire with high temperature insulation or be very sure that the wire in securely held away from any components which will get hot. You don't want a PVC insulation fire. After making this fix I happened to look at a new unit in the chandlers, and the same fix had been implemented in manufacture, so if your cooker is relatively recent, it may already have the earth return in place. In that case all you can do to be make sure the connections are clean and tight. MP.
  12. I moved to Three from EE a couple of years back, on cost grounds. I'm seriously considering moving back. It's clear that Three have way oversold their network capacity in many places, and though it's possible to get a decent signal, either the radio bandwidth or the backhaul capacity is congested and bandwidth and round-trip-times are not good. One trick I have used with success in quite a few places it to force the router to use 3G rather than 4G. Three has/had an excellent 3G network (the clue is in the name) - much better than EEs which was never much cop. It's clearly mostly still in place, and because most devices prefer a 4G connection when both are available, the 3G network is less loaded and often gives better transfer speeds. MP.
  13. Less competition. Oh. MP.
  14. Foxton is only steep because the builders made it so. The summit clings to the contour until the last minute when there's nowhere else to go and then drops steeply. There's a lovely gentle slope from the as built line for at least the last half mile where the canal could have descended more slowly. MP.
  15. Blowing an absolute hooley in Hurleston. MP.
  16. The Jericho VMs are full of ankle-breaking collapse holes. I've reported them before, and work has been done, but it never seems to last. MP.
  17. Check the link. Modified moving average doesn't require storing a fixed number of samples and the influence of old samples falls out of the result automatically at a rate determined by the n parameter and the number as samples per second being fed into the calculation. I sample as fast as possible and pick n so that it takes a second or so to slew to a new reading. Pick n as a power of two, as the algorithm divides by it, and be aware that the accumulator's maximum value is the maximum sample value multiplied by n, so you might need to worry about overflow. No server running permanently, the information ends up on my laptop. Each record has a 32-bit serial number, and the EEPROM in the Arduino can store the last 8192 records in EEPROM. The program on the laptop knows the serial number of the last record already in the file on disk, asks the Arduino what the serial number of the most recent record is, then requests all the records between those two serials and adds them to the end of the file. I log a record every five minutes, so as long as I plug the laptop in once a month, I have a complete copy of the log. For the first couple of years, I just plugged the USB from the Arduino into the laptop. Now I have a serial line from the Arduino connected to a serial port on my internet router, so the laptop can talk to the Arduino via the internet. The router still doesn't store the data, it's just a way for the laptop to talk the same protocol as it does via USB, but remotely. MP.
  18. The main problem to solve is finding where the log data starts and ends. The obvious solution is to keep that in a dedicated location in the EEPROM, but then that location gets written every time the log is updated, while all the other blocks are written every n updates, where n is the size of the EEPROM in log entries. I have designed a self-describing log format in the past, where you just write the new block at each log, and a scan through the whole thing at startup is enough to tell you where the valid data starts and ends. The current code uses a two-step approach. The metadata is stored in the 1k on-chip EEPROM and the logs in the i2c EEPROM. On chip EEPROM has a single location which points to the actual metatdata . The metadata includes an update count and when it has been updated 65356 times, the initial pointer is updated and the metadata moves along to new unworn locations in EEPROM. That extends the theoretical lifetime from months to decades. Getting the data out over the serial line is easier and less code than writing a filesystem on an SdCard, I think. MP.
  19. For oversampling, I used modified moving average, which is really easy to calculate. The article bellow has the details. https://www.baldengineer.com/measure-pwm-current.html I tend to make n a power of two to optimise the code. For logging I used an 8 pin i2c EEPROM which is arguably easier to wire up than an SD card, and certainly easier to read and write using an Ardunino. You do have to arrange your own wear-levelling though (don't have a single root block that gets written on every logging event and will wear out first.) The Ardunio MCU has 1k of EEPROM built in which is sufficient for quite a bit of logging if you optimise record size and logging frequency. MP.
  20. I know it's not what you are asking, but here are plenty of cases where the canal has had to accommodate "improvement" of existing roads at a later date, to the detriment of the canal. For example, the A51 road bridge between Barbridge and Calverley which adds a nasty blind bend to the canal that almost certainly wasn't there before. Ditto the road bridge just south of Saltersford tunnel. Newer roads are better: there seems to have been an era in the 50s and 60s where the bridge had to be built because closing the canal was too hard but nobody really believed that it would last, so the minimum possible to keep the canal navigable was built. MP.
  21. This post cannot be displayed because it is in a forum which requires at least 10 posts to view.
  22. That sounds similar to my first (failed) attempt at hardware, and would definitely have been better if I'd been able to make it work. My point is that the simple-minded solution with Arduino analog inputs works well enough and is simple to do, as long as you understand a few gotchas. MP
  23. On subject of Arduino cell voltage monitoring, my system uses the simple and obvious method of measuring the voltage WRT ground at each cell junction using potential dividers. I divide the voltage by 6 and use the built-in 2.56v band-gap analog reference in the microcontroller. That gives a range of 0 to 15.36 volts and a resolution of 15mV at the least-significant bit for the 10 bit ADCs in the Arduino. By oversampling I get values which are accurate (or at least consistent) to within about 25mV in practise. Individual cell voltages are obtained by subtraction, in the obvious way. This all works fine, but I'd say the resolution is only just good enough. If I was starting again I'd use a microcontroller with a 12-bit ADC. Beware of the specs on the microcontroller for the maximum voltage at an input pin. This is normally given as Vcc plus a small margin. Since I'm dividing the voltage by six, and using 5v Vcc, all is fine as long as the Arduino is powered up. If it's off and Vcc is zero the input pins are still connected to the voltage dividers and the maximum voltage above Vcc spec is wildly violated. You can probably rely on the chip's built-in protection diodes if the potential divider resistors are high enough (and you want them to be high to avoid parasitic discharge) but to be sure I added discrete 1N4148s from each cell voltage input pin to Vcc. They are normally reverse biased, so have no effect, but when the Arduino is off and Vcc is low they conduct and limit the pin voltage to Vcc+0.6, which is safe. I bought 0.1% resistors for the voltage dividers, but they still need calibration factors to be added in software to get readings which agree with my multimeter. (The multimeter ain't necessarily that accurate, but it can be assumed to have consistent errors, so I trimmed the calibration so the cell voltage read by the Arduino agreed with the multimeter for each cell.) MP.
  24. Please could you define what "wokeness" is, in your opinion. MP.
  25. Mine certainly doesn't say Lucas anywhere on it. MP.
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