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dmr

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dmr last won the day on July 22 2023

dmr had the most liked content!

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About dmr

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  • Gender
    Male
  • Location
    on the boat
  • Interests
    Narrowboats
    Life on the cut
    Engineering (Engines, Electronics and Software)
    Walking the dog
    Drinking Beer
  • Occupation
    Engineer , semi (mostly?) retired.
  • Boat Name
    Vox Stellarum
  • Boat Location
    Winters on the Rochdale, Summers on the cut

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  1. Modern engines are horrible, they sound horrid and have no character. The A series was a lovely engine with a very pleasing tickover, especially with a little bit of wear in the timing chain. The B series was even nicer. BL were very proud of those long bolts holding the K series together, they were actually a very innovative company even though things often went a bit wrong. We did briefly own a modernish metro as a stop gap while all the other cars were awaiting me to find time to fix them. I wanted to hate it but that K series was a lovely eager free revving engine.. My daughter learned to drive in it and still misses it. Sadly the release bearing went so it was added to the list of broken cars that I never quite got round to fixing.
  2. If this is an integral tank then at some stage you will need to get in there and repaint it. At this time you will find that plastic cap and maybe a couple of other things, hosepipe fittings and the like. This is normal and don't worry about it. Frogs and fish etc are slightly more concerning.
  3. Do they sell BMC recons? or maybe Golden Glow?
  4. Yes, I remeber all those dodgy adverts for gold and silver recon BMC's. I wonder if they did a bronze version too....no recon at all, straight from the scrapyard with a quick coat paint 😀.
  5. I agree. So if Zeus is reading the phase/tacho/W signal via an ADC then it could all be done very neatly, but if Zeus is reading the squared up signal as a digital input it can't be done quite as well or safely. If Zeus is in float or shut down then the Tacho signal signal is really not important (unless its sharing it on the CANbus), as far as I can see its only real purpose is to support the speed dependant duty cycle limit. As an aside the speed dependant duty cycle limit does not really work for me, there are not enough speed points, so I can't limit it at tickover without also reducing it at lower running speeds. The new Victron DC-DC converters look dead good so an option for lithium would be to connect the domestic alternator to the starter battery and charge the lithiums via the DC-DC. Two converters cost less than a Zeus 😀. I really need the duty cycle and temperature limits so the Zeus is the best option for me.
  6. Maybe I didn't explain my thinking too well?? If we want a simulation of a traditional warning light which can detect belt (or brush) failures then this should only come on if Zeus is providing significant field drive and not detecting corresponding output current. The light should not come on if there is no charge, and probably not during float. Something more complicated like Nick describes might be better, but I would really just like to just see a light come on and go off when I start the engine so a simpler system should work. Assuming most Zeus systems are controlling the domestic alternator comprehensive detection of belt failure is a bit less critical as its usually the starter belt that drives the water pump. Taking the tacho signal from the starter alternator sounds like an exellent idea, but I don't think I can be bothered to redo the wiring but will if Arco make suitable changes to their software. I have disabled the "tacho required" option because as you say its really not that significant.
  7. The Zeus does not suppport a traditional warning light, maybe this is part of the reason. It should be relatively easy to sort this out in software, if there is no field drive then a tacho signal is not expected so the light should not/can not light, but when there is a field drive then the light should come on if there is no output current. This is where that alternator shunt really does become useful 😀. I am starting to see that an alternator shunt is actually potentially quite useful. Alternator current does drop off quite a lot as the alternator warms up so if I want to limit current when the alternator first starts (to control belt slip) but still have a good current when the alternator is hot then working off alternator current rather than duty cycle might be a good idea......but Zeus does not do this. ============================== Here is part of a data log from Zeus. This shows the current falling off as the alternator warms up. Ive got duty cycle set to 65 maximum and alternator temperature set at 65/75 which is probably a bit low. This all just about works but I would be happier limiting start up current to 70 amps but this would stop me getting 70 amps when the alternator is hot (or would if I increased the alternator temperature a bit) blue: current red: duty green alternator temperature
  8. Thats how I read it too. Im not sure that Jotun 90 is the best primer for topsides, but maybe it would be ok if it was sprayed on?
  9. Unless I missed it there is almost zero documentation available for the Zeus, its operation and the the App, just the installation wiring diagrams. Maybe this will turn up soon??? Have just set my minimum duty to 0%. I want to get 100% confident in the Zeus before I think about replacing the Trojans with Lithium. Also just reduced my maximum duty to 65% and still got over 80 amps out of the alternator (100amp Iskra) when I first started the engine. I would like to limit it to about 70 as its running off a single V belt, but if I do that I might not get enough current when the alternator is hot. I will post some graphs of logged data in the next day or so.
  10. A bit of lateral thinking......does this actually matter in most instalations? On my engine the main tacho comes from the "starter" alternator. The Zeus controls the domestic alternator and if that goes into float the only consequence is that Zeus cannot display rpm, but as its not really doing anything that does not matter? The issue is that 0% minimum duty should be the default, and should only be changed in special circumstances? The entire concept of driving the tacho off the alternator is a bit historic, and on modern systems that run something like the Zeus the tacho should ideally come from a cam or crank sensor (though this is still rare). To answer your post, a lot depends on how Zeus handles the tacho signal, it might be possible to do a firmware upgrade but if the tacho signal goes via a comparator or directly to a digital input then its a hardware change that would be required. If you get the scope out again then report back on typical voltages at low field drives???
  11. ok, I have no first hand experience of this. I wonder how many volts Zeus needs to deduce speed?. A user configurable limit would be a bit of a pain, I would think that an automatic system could be deduced, something like Nick desribes for his alternator control chip. The "tacho required" is a bit usefull in that it alows the start delay and soft ramp to work correctly even if the engine is a bit slow to start for some reason, but in almost all cases this should not really be required. I have been using Zeus to control Alternator temperature. It looks like there is some learning going on and it has got very good at holding a steady temperature (within 1 degree) with only small modulations in duty cycle......BUT, I have to specify a target temperature and a maximum temperature (65 and 75 in my case) and Zeus aims for something mid way between these (69/70) while I think it should aim for the lower temperature. A problem with this is it constantly gives a "temperature high" status message. More seriously, despite setting a temperature limit and duty cycle limit, I believe I saw Zeus apply 100% field for maybe a minute or too causing a high alternature temperature. It could potentially have given a high voltage if it had been past the bulk phase. Sadly I did not manage to record this. I suspect this happened because I had gone back into the saloon with my phone which was right on the edge of the Bluetooth range and Zeus somehow got sidetracked into trying to reconnect, but this is only a guess.
  12. Its good, I like to hear stuff like this, maybe I should have talked to you and used your design, but its a lot of time and effort that I don't have, but I am a huge believer in the concept of a "one man band" competing with the big (biggish) companies. I don't really see what the big issue is with float mode and tacho signal, maybe I have not thought hard enough 😀, surely it only needs a volt (or even much less) to deduce speed, so as long as a tiny bit of rotor excitation is applied (well below float voltage) there should be enough voltage. Its a zero crossing thing? Is the residual magnetism not enought? If you wanted to be really pedantic you could apply just enough rotor drive to get a tacho signal but not turn on the rectifier diodes 😀
  13. I've had my Zeus running for a while now and have used its data logging feature to try to understand how it works and how well it works. Its an impressive device but does have a few "features" some of which must be bugs and one or two that are potentially destructive. Arco have not responded to most of my questions/bug reports. I will write a bit more later/tomorow, but on the subject of the warning "ignition" light. Arco did respond to this and tell me the light should NOT light when the ignition is on but no engine rotation, so this is correct behaviour. I disagree with this, and don't understand why the software gives an option for "fault" or "warning light" when it only shows faults. So why should it work like a standard ignition light? There are two big reasons. When you turn the ignition on in a car all the lights on the dash light up to confirm that the bulbs are working...without this the bulb or wiring could have failed and you would never know so miss any error flashing. Second, it gives instant feedback that the alternator is working (brushes do eventually fail 😀). Everytime I start my engine I watch for the ignition light going out, I don't always look at the BMV (or the Zeus app) to see what the current is. I realise that the soft ramp confuses things a litttle bit but still think that light really should light up.
  14. USB C was a victory for the computer scientists and a defeat for the engineers, maybe a good idea but just too complicated to be reliable.
  15. Try a different cable and USB socket, these things can be very temperamental and fussy. I suspect its USB C? These have loads of little contacts inside and it only takes a bit of wear for it all to go wrong.
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