OP
suntrap
Excellent stuff! Would love to see the circuit diagram.
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There is a 5V version available.
Ah sorry of course - the correct part would be an MCPC2425A or an MCPC2450A, neither of which RS sell.Taken a look. Its a burst fire controller, not a proportional controller.
Excellent stuff! Would love to see the circuit diagram.
Ah sorry of course - the correct part would be an MCPC2425A or an MCPC2450A, neither of which RS sell.
I'm surprised that the value of R1 & R5 burden resistors are so high.here is schematic for control loop. I haven't finalized the +- 15v supply components so haven't included them will post full schematic when finished
I'm surprised that the value of R1 & R5 burden resistors are so high.
I'm using a CT with 3000 turns and a burden resistor value of just 240R which gives me -2.5V to +2.5V (5V p-p) when reading 5kW.
I found this handy online calculator for CT's/Burden resistors, so you can determine safe peak voltages without damaging your op amps if it helps.
Thanks for sharing your schematic, there are so many good ideas surfacing now.
Ah that makes sense. It might be worthwhile including 'nominal' burden resistors in your schematic, because if someone else builds your project using standard CT's (no internal burden resistor), the excessive voltage may damage the op amps.r1 and r5 are not burden resistors they hold the i/ps to zero as a precaution if the CT's are removed. the owl ct's give 0.1v per amp which implies they have a burden resistor built in I presume for safety reasons.
Ah that makes sense. It might be worthwhile including 'nominal' burden resistors in your schematic, because if someone else builds your project using standard CT's (no internal burden resistor), the excessive voltage may damage the op amps.
I have been caught out twice now, whilst disconnecting my CT's from the PCB, have had unwelcome reminders at what high voltages are developed across the coil whilst no resistor is there to reduce it. The first time, by reaction, I snatched my hand away and cut it on an adjacent metal frame. The second time, I was miffed because I hadn't learnt from shock#1!!
i have been reading though this tread with great interest, i have just a one question has any thought about using a
900W Heating Element with Thermostat the type that goes in towel rads? just pluged into the feed?
thanks
Try these CT's, they are each rated 3000:1 coil ratio, and at £16.50p FOR 2, they are tremendous value, and from my experience produce very good results. I'm well pleased with them.I'm pondering the best/easiest/most cost-effective route to inputting real time data into whatever microprocessor does the clever stuff (probably Arduino/Nanode).
The LEM CTs look expensive but I'm sure they are wonderful.
Anyone have any experience of Efergy units (cheap on Ebay) but at 90A won't they reduce accuracy?
Efergy Standard Sensor - Jackplug Fitting | eBay
Likewise I see owl CTs at a reasonable price on Amazon but cant find the spec.
OWL CMA113 Standard Sensor Fior Economy 7 Users or 3: Amazon.co.uk: Electronics
Also come across a SCT-013-030 which seems only available in USA. Anyone have any details / UK supplier?
Non-invasive AC current sensor SCT-013 (30A max) Non-invasive AC current sensor SCT-013 (30A max) [SEN005] - $9.90 : iStore, Make Innovation Easier
Finally a (silly?) thought. As I have a CC EnviR unit and additional clip-on CTs with wireless senders, which I understand operate on433MHz SRD band, the same as an Anduino shield. Could I not just pick up the existing transmitted data using the shield? Maybe a better Q for FreeEnergyForum
Hi do you have a link to a product?
I moved the RCBO for the solar feed to be next to the main incomer in the cs unit and then put the CT around the the incoming meter tail and the solar feed live which are now right next to each other. second CT just goes around the solar feed live all nicely contained in the CS. My CS is a large MK sentry so there is plenty of room.
Hi innie,Hi John
Have a look at Picture 1 of 5 from Power controller Sorry but it's just a sketch but it will give you the idea. The picture shows one way of connecting. The other will take the feed from the house dist board to the triac, but the circuit used is not passive but reactive , in regard that it balances the two power levels. I haven't posted that version yet but I will in a few days. I will add it to the collection of pics. I can say that I have tried the method of fitting all the cores through one ct and it's not easy. It is so much better to fit a Henley block.
Regards
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