More PV @ Courtiestown

[marshman]

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

[Fintray]

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.htm

Relevant 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.

[linesrg]

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

[sam_cat]

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.

[marshman]

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

[Philip R]

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

[linesrg]

Good Evening All,

Didn't get too much done today.

Battery charging is continuing.

Tied up the two remaining CAT5e cables (SMA Energy Meter and imminent SI) and found an old, intact, egg lurking in a 'hole'.

Prompted by nowty's re-wired CU I've been studying my install and the plan for the arrival of the SI-4.0M. This seems a suitable candidate? - https://www.switchgeardirect.co.uk/product/havells-hsdrcd16ms-16way-dual-rcd-high-integrity-metal-consumer-unit-100a-main-incomer-and-2x-63a-rcd-am3-compliant-fully-loaded/?gclid=CjwKCAjwqLblBRBYEiwAV3pCJoZWXTG4ROZSeN-5rkpx4s68AUQmHdengk9w1IQu4PfAOOZxjnrUIhoCISIQAvD_BwE

Regards

Richard

[linesrg]

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

[linesrg]

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

[linesrg]

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

[pantsmachine]

Good to see it all working.

[biff]

Well done Richard,
                       You are getting there. It looks impressive.
                                                  Biff

[linesrg]

Good Morning All,

The Growatt discharging at 0200 this morning.

Regards

Richard

[linesrg]

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

[linesrg]

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