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  1. flippineck

    Current transformer

    I think I'm probably misapplying the parallel resistor equation in this thought process. For R1 & R2 I'd originally ordered a pack of 10 x 330 kΩ 1% 2W resistors, I was hoping a high value might keep battery drain down.
  2. flippineck

    Current transformer

    Just now I saw it as three resistances all in parallel, applied 1/Rt=1/R1+1/R2+1/R3 and got 38.7Ω That can't apply, can it?
  3. flippineck

    Current transformer

    Just found this highly integrated solution, any comments welcome? http://www.farnell.com/datasheets/2950532.pdf
  4. flippineck

    Current transformer

    Thanks. I now get, using two parallel 100Ω resistors; 40 A RMS primary / 2500 turns secondary = 0.016 A RMS into 221Ω giving rise to 3.536 V RMS over 221Ω = 4.99 V peak, either end of the two parallel 100Ω resistors? Since the Arduino is measuring RMS current by repeated sampling, and it's...
  5. flippineck

    Current transformer

    I have a small through-hole type current transformer https://docs.rs-online.com/93d6/0900766b8169af7d.pdf with a coil ratio of 2500:1 with a single pass of live 240V AC 6mm² conductor through the hole. If my calculations are correct, feeding the secondary across a 100Ω burden resistor should...
  6. flippineck

    Where to start

    Had a short career as a domestic/industrial electrician many years ago, 5 years or so going from mate through to time served C&G qualified, wasn't a lifelong tour of duty but did give me some solid experience (including quite a few bangs!) and some appreciation of mains voltage issues. I was on...
  7. flippineck

    Where to start

    I have some limited prior experience programming in the following, with best ability in the first languages and worst as you go down the list.. php perl BASIC javascript C 1980's PLC ladder logic Z80, 6502 assembly Ability level going from slightly sub-moderate down to slightly above poor...
  8. flippineck

    Load auto-detect

    My own main generator is a 10kVA Stephill generator powered by a 3 cylinder Kubota diesel engine. As the link above points out, although this is great for 10 minutes when someone plugs a kettle in whilst making toast and heating beans in the microwave, it would be less efficient to have it...
  9. flippineck

    Load auto-detect

    This is in relation to an outbuilding with a small single-phase 240V AC ring main, fed by a diesel generator with a remote auto-start feature. I saw a device advertised which you attach to the ring, and to the generator's auto start signal input. From the advertising info, it seems it applies a...
  10. flippineck

    Homebrew passive antenna coupler

    Sorry to say, I never took this any further & no longer have the phone
  11. flippineck

    Retrofit house with LEDs

    Thanks. I'll try just one 12VDC supply to start with & maybe get the multimeter on it to see what voltages and currents are where. It's actually looking like a lot of the existing ceiling transformers are well due for replacement anyway - found more than a couple of the seemingly blown...
  12. flippineck

    Retrofit house with LEDs

    8-pin DIL chip seems to be marked 02521EG or 0Z5Z1EG ( possibly EGM) CJ2J7F.20 what looks like 4 fat diodes are 5554B inductor on one side marked 680
  13. flippineck

    Retrofit house with LEDs

    One popped (whilst being driven by one of the original incandescent driver transformers) so I decided to open it up. Sorry about the quality, struggling with a very old phone cam here. Apologies for the bottle of clove oil, I've toothache :-( Hoping that you guys might be able to tell enough...
  14. flippineck

    Retrofit house with LEDs

    Best info I can find for the spot bulbs I'm using. Taken from several sources, accurate detailed info seems to be hard to find. ASDA energy saver LED MR16 5.2W GU5.3 Supermarket code 5 054781 983262 Made in China for ASDA stores ltd YKMR16B3-5.2W Voltage DC/AC 12V Current 850mA Power 5.2W PF...
  15. flippineck

    Retrofit house with LEDs

    Used to be up to speed as an installation sparkie but that was a long time ago, it was 16th edition in the UK when I was doing it, think they're up to 18th edition now.. I left the electrical installation trade to become a comms engineer around the time LEDs were just beginning to make the...
  16. flippineck

    Retrofit house with LEDs

    Moved house, and found that a few rooms have a bunch of 12v incandescent halogen reflector bulbs fitted in the ceilings. Two rooms have six 35W lamps, another has five 35W lamps, another has 5 in it's ceiling. Have been going round replacing all these halogens with LED equivalents & so far...
  17. flippineck

    Lithium ion cell equivalents

    I think there's 7 cells in the original pack - I've not looked at exactly how they're connected to the control circuit yet, parralel, series, combination of both etc.. but I was also wondering about the possibility of replacing all the cells with a suitable number and interconnection, of a...
  18. flippineck

    Lithium ion cell equivalents

    Looking for a UK supplier for the following: Lithium-ion Moli IMR-26700A 2900mAh 3.8V Cylindrical High Power Cells Specifications Manganese dioxide based Li-ion battery cell 2900mAh, 3.8V, max 40A discharge A number of safety features were designed into the IMR-26700A cell, including thermal...
  19. flippineck

    125 degree C electrolytics by Su'scon

    Just found & checked the datasheet for the Panasonic FR series caps I used - it does say they are low ESR. Phew. Noticed it says 'endurance at 105 deg C - 5000/10000 hrs'. Given the fact I tended to leave this monitor switched on 24/7, I guess I'm lucky it's lasted as long as it has! Given that...
  20. flippineck

    125 degree C electrolytics by Su'scon

    Thanks folks, soldering in what I've got.. will then stand well back before flicking switch. You have me concerned now regarding low ESR What I've ordered are all Panasonic FR series
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