marshman
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« Reply #300 on: April 10, 2019, 12:07:45 PM » |
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Multi turn pots, (try searching 10 turn instead), are getting rare in this digital age, high value ones especially so. You could use a "normal" single turn 250k with another 25k or even 10k in series. The 250k giving the coarse adjustment and the 25 or 10k giving the fine adjustment. I made a Practical electronics supply years ago and this recommended multiturn puts to set current and voltage limits, I just used single turn (poor hard up apprentice at the time), and it is OK just a little coarse on the settings - still working fine lots of years later - just given myself a shock (not literally!) as I realise how long ago it was!
Roger
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3.15kWpk (15xSharp ND210)/SB3000. & 3.675kWpk (15 x Suntech 245WD)/SB4000TL, 10kW GSHP driving Wirsbo underfloor heating from 1200m ground loops. 10' x 7' solar wall (experimental). Clearview 650 Wood Burning Stove. MHRV - diy retrofit. Triple glazing.
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Fintray
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« Reply #301 on: April 10, 2019, 12:31:45 PM » |
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Hi Richard Going on what Roger has said this article also backs it up so doesn't look too hopeful: http://sound.whsites.net/pots.htmRelevant section - Because they are variable, there is a much smaller range of potentiometer values, almost always in a 1, 2, 5 sequence. Common values for panel pots are 1k, 5k, 10k, 20k, 50k, 100k, 500k and 1Meg, and there are also pots with more or less resistance than the small example here. There are also some intermediate values, such as 22k, 25k and 47k and often some seemingly odd values that are usually intended for specific applications and may be very expensive. Values such as 2.5k and 250k went missing along the way, and these are not stocked by very many distributors. 25k pots are becoming harder to get as well. Not all values are available in log and linear, and in some cases you may even find that for a particular type, you can get them in any value you want, as long as it's 100k (for example). P.S. The article is from 2002.
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« Last Edit: April 10, 2019, 12:33:20 PM by Fintray »
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3.87kWp PV 10.24kWp PV SolarEdge system Tesla Powerwall 2 100 x 47mm Navitron tubes (still being installed!) MK2 PV router DHW diverter Morso 5kW WBS Nissan Leaf
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linesrg
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« Reply #302 on: April 10, 2019, 12:38:10 PM » |
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Fintray/ Marshman, I guess one fallback would be buying a 10 turn 50k and 500k potentiometer and only using the first 5 turns?   ? I don't give up easily  I'm very aware things have moved on quite away since I started in electronics as a hobby back in 1970............... My initial thinking about 'having' to buy a dedicated cheap Chinese built device off eBay has at least been averted and forced me to break out the soldering iron. Regards Richard
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1.28kW on a Lorentz ETATRACK1000 + 1.44kW/ SB3000TL-21 (FIT), 1.28kW/ SB1700 (ROO/FIT). CTC GSi12 heat pump/Ecosol/Flowbox 8010e/Gledhill ASL0085 EHS/3off Navitron 4720AL Solar ET & Immersun T1060/T1070/T1090. 3.375kW/ SMA SB3600TL-21 and a Sunny Island 4.4M-12 c/w 15.2kWh battery and a Renault Zoe.
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sam_cat
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« Reply #303 on: April 10, 2019, 01:14:59 PM » |
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Fintray/ Marshman, I guess one fallback would be buying a 10 turn 50k and 500k potentiometer and only using the first 5 turns?   ? I don't give up easily  Just put 50k R across lugs 1 and 3 and you end up with 25K.
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marshman
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« Reply #304 on: April 10, 2019, 02:57:32 PM » |
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Fintray/ Marshman, I guess one fallback would be buying a 10 turn 50k and 500k potentiometer and only using the first 5 turns?   ? I don't give up easily  Not necessarily, depends on how the pot is wired in the circuit. If the circuit is dependent on the 250k resistance and it is not simply a voltage divider then effectively doubling the resistance will probably have an effect. I am sure I will be teaching you to suck eggs but I assume the idea of the 10 turn pot will be to allow precise and easy setting of either the current limit or voltage limit circuit. So fitting a single turn pot will achieve the same thing just much harder to set to a precise value, hence my suggestion to to but a lower value pot effectively in series (you would need to study the schematic to decide the best place) that way you "centre" the low value pot, adjust the large value one to get close to the desired voltage or current, then "fine" adjust up or down using the low value pot, you don't need 10 turns on any pot if you do it this way. To be honest I find 10 turn pots a pain, you can't quickly go from a low to a high setting. Roger
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3.15kWpk (15xSharp ND210)/SB3000. & 3.675kWpk (15 x Suntech 245WD)/SB4000TL, 10kW GSHP driving Wirsbo underfloor heating from 1200m ground loops. 10' x 7' solar wall (experimental). Clearview 650 Wood Burning Stove. MHRV - diy retrofit. Triple glazing.
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Philip R
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« Reply #305 on: April 10, 2019, 06:14:34 PM » |
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What (Watt) dissipation you require. I have to be careful here as I dont want to give advice that results in devices smoking!
Bourns certainly used to and probably still do do a decent range of multiturn pots and the multiturn counting knobs that go with them.
Philip R
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linesrg
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« Reply #307 on: April 11, 2019, 08:14:27 PM » |
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Good Evening All,
The SI is arriving with the vendor on Tuesday but I've asked them to hold off as I'm heading back to work tomorrow.
Went out and planned what I needed for a replacement CU and ordered the necessary bits.
The latest Growatt battery is due on the 18th.
Hopefully things will come together towards the end of next week insofar as all the necessary bits will be on site.
Finished test charging the other Growatt modules today.
Regards
Richard
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« Last Edit: April 12, 2019, 07:12:44 AM by linesrg »
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1.28kW on a Lorentz ETATRACK1000 + 1.44kW/ SB3000TL-21 (FIT), 1.28kW/ SB1700 (ROO/FIT). CTC GSi12 heat pump/Ecosol/Flowbox 8010e/Gledhill ASL0085 EHS/3off Navitron 4720AL Solar ET & Immersun T1060/T1070/T1090. 3.375kW/ SMA SB3600TL-21 and a Sunny Island 4.4M-12 c/w 15.2kWh battery and a Renault Zoe.
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linesrg
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« Reply #308 on: April 12, 2019, 07:00:25 PM » |
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Good Evening All,
Stayed in the flat overnight ahead of flying out to work this afternoon (this being sent from a secret location in the North Sea). Went out this morning to get my hair cut and came back to the flat at 1115 to find a parcel had been delivered.
No big deal in itself other than the order was only placed at 1510 yesterday afternoon with TLC - impressive. I know the new consumer unit bits will be there when I get back....
Regards
Richard
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« Last Edit: April 13, 2019, 12:37:51 PM by linesrg »
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1.28kW on a Lorentz ETATRACK1000 + 1.44kW/ SB3000TL-21 (FIT), 1.28kW/ SB1700 (ROO/FIT). CTC GSi12 heat pump/Ecosol/Flowbox 8010e/Gledhill ASL0085 EHS/3off Navitron 4720AL Solar ET & Immersun T1060/T1070/T1090. 3.375kW/ SMA SB3600TL-21 and a Sunny Island 4.4M-12 c/w 15.2kWh battery and a Renault Zoe.
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linesrg
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« Reply #309 on: April 13, 2019, 12:36:45 PM » |
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Good Afternoon All,
We're 'cooking on gas' today at Courtiestown, the two simultaneous shots below from the Immersun and the Growatt, the latter charging at 1kW.
Regards
Richard
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1.28kW on a Lorentz ETATRACK1000 + 1.44kW/ SB3000TL-21 (FIT), 1.28kW/ SB1700 (ROO/FIT). CTC GSi12 heat pump/Ecosol/Flowbox 8010e/Gledhill ASL0085 EHS/3off Navitron 4720AL Solar ET & Immersun T1060/T1070/T1090. 3.375kW/ SMA SB3600TL-21 and a Sunny Island 4.4M-12 c/w 15.2kWh battery and a Renault Zoe.
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pantsmachine
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« Reply #310 on: April 13, 2019, 01:26:45 PM » |
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Good to see it all working.
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HUGE insulation depth. 5.12 kw PV system with Solar edge. 4.8 kw Pylon tech battery storage. All Low energy bulbs. Solar I boost charging 210 ltr OSO system tank. Balanced & zoned CH wet system & Hive 2 Wood fired thermosiphon cedar hot tub. Masanobu Fukuoka inspired veg garden & fruit trees
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biff
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« Reply #311 on: April 13, 2019, 07:30:42 PM » |
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Well done Richard, You are getting there. It looks impressive. Biff
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An unpaid Navitron volunteer,who has been living off-grid,powered by wind and solar,each year better than the last one.
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linesrg
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« Reply #312 on: April 14, 2019, 01:55:45 AM » |
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Good Morning All,
The Growatt discharging at 0200 this morning.
Regards
Richard
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1.28kW on a Lorentz ETATRACK1000 + 1.44kW/ SB3000TL-21 (FIT), 1.28kW/ SB1700 (ROO/FIT). CTC GSi12 heat pump/Ecosol/Flowbox 8010e/Gledhill ASL0085 EHS/3off Navitron 4720AL Solar ET & Immersun T1060/T1070/T1090. 3.375kW/ SMA SB3600TL-21 and a Sunny Island 4.4M-12 c/w 15.2kWh battery and a Renault Zoe.
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linesrg
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« Reply #313 on: April 18, 2019, 01:38:49 PM » |
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Good Afternoon All,
That's me back onshore. I've spent part of this morning soldering crocodile clips onto fuse holders and an awfully nice courier man has delivered a pallet with a shiny new Sunny Island 4.0M.
That's plenty of stuff to be getting on with now. First off will be getting on with mounting the SI on the wall and I'm waiting on the best of the sun going down before I start re-wiring things on the far side of the steading.
Regards
Richard
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1.28kW on a Lorentz ETATRACK1000 + 1.44kW/ SB3000TL-21 (FIT), 1.28kW/ SB1700 (ROO/FIT). CTC GSi12 heat pump/Ecosol/Flowbox 8010e/Gledhill ASL0085 EHS/3off Navitron 4720AL Solar ET & Immersun T1060/T1070/T1090. 3.375kW/ SMA SB3600TL-21 and a Sunny Island 4.4M-12 c/w 15.2kWh battery and a Renault Zoe.
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linesrg
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« Reply #314 on: April 18, 2019, 06:06:49 PM » |
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Good Evening All,
This is the lengths I have to go to when neither of my sons is available when I have a 44kg lump to deal with........
Regards
Richard
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1.28kW on a Lorentz ETATRACK1000 + 1.44kW/ SB3000TL-21 (FIT), 1.28kW/ SB1700 (ROO/FIT). CTC GSi12 heat pump/Ecosol/Flowbox 8010e/Gledhill ASL0085 EHS/3off Navitron 4720AL Solar ET & Immersun T1060/T1070/T1090. 3.375kW/ SMA SB3600TL-21 and a Sunny Island 4.4M-12 c/w 15.2kWh battery and a Renault Zoe.
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