Vero-29 3Kw Big Build (copied across from other forum)

freemanjack

freemanjack

Well-Known Member
GreenMotion said:
Glen is really nice and helpfull. Will be putting in an order with him for 5 drivers and potentiometers. I will let you know how his service is, so you can check if it is something for you.
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If the order was for anything bigger than the 250w ones they list publicly they may take some weeks to ship as they customise the transformers to order. The >250w normally arrive in about 10 days from order, and yeah, glen is incredibly helpful and diligent too.
 
GreenMotion

GreenMotion

Member
freemanjack said:
If the order was for anything bigger than the 250w ones they list publicly they may take some weeks to ship as they customise the transformers to order. The >250w normally arrive in about 10 days from order, and yeah, glen is incredibly helpful and diligent too.
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Yeah, its awesome. He can even make a 300w driver at 7,2 amps for 60 ish dollars. I can see people using 1 driver to power a bunch of their cobs.
 
freemanjack

freemanjack

Well-Known Member
Thermistors just arrived from mouser, few days late but I should still have enough time to shoot a 'how to' vid providing my component selection is in value, the availability of many 'through hole' passive electronics are now becoming hard to find or expensive to buy as the electronics industry moves down the road of surface mount only, I may need to look into making my own circuits for some of these devices but its hardly 'home gamer' so i'll keep plugging at 'through hole' where poss.
 
freemanjack

freemanjack

Well-Known Member
freemanjack said:
Should have the thermistors coming tomorrow, will make a new vid covering basic thermistor thermal protection utilising the 10v dimming circuit. Also worth mentioning, 4 of the 5 of these 600w monsters are going into a single veg room, I've been in touch with a chinese supplier discussing a 1000w driver for this array, initial thermal soak tests would suggest 850w is not excessive for the total capacity of these CoB's given adequate heat dissipation. So I might do a kilowatt test on this rig before it ships to the client.
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WINNING!!! well...... TOTALFUCKINFAIL! then some headscratching, then a few more bucks, then WINNING! thermistors from mouser arrived yesterday afternoon, DOH! 300ohm!!! coulda sworn i'd triple checked they were 300kohm!!??? fuckit, only 1000x too low a value! another £17 dahn tha drain, ho hum, back on the catalogues, 330kohm replacements ordered and arrived and WIN! perfect linear dimming from about 50c, will vid the results next day or so. Also ordered that 800w'er from my new chinese supplier, will post those results soon as.
 
Trippyness

Trippyness

Well-Known Member
freemanjack said:
WINNING!!! well...... TOTALFUCKINFAIL! then some headscratching, then a few more bucks, then WINNING! thermistors from mouser arrived yesterday afternoon, DOH! 300ohm!!! coulda sworn i'd triple checked they were 300kohm!!??? fuckit, only 1000x too low a value! another £17 dahn tha drain, ho hum, back on the catalogues, 330kohm replacements ordered and arrived and WIN! perfect linear dimming from about 50c, will vid the results next day or so. Also ordered that 800w'er from my new chinese supplier, will post those results soon as.
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Wish I would have known this before I ordered drivers for my 15 Vero 29's . Next time.
 
freemanjack

freemanjack

Well-Known Member
OK folks, update on thermistor tests, looks like this latest choice may be pretty much on the dot fer specs, got it cobbled onto the h/s on the top directly above the centre cob, cold power was nearly full power @ 285w so my 25c 330kohm choice is within a hairs crack of poific in that respect and as to temp gradient, its looking promising (if not quite perfect) pulling the wattage down to about 240w @ approx 60c on the h/s with all fans disconnected (replicating worst case scenario) and look to have more or less stabilised at that. I had calculated the value to dim by nearer 50% @ 50c but this discrepancy will be due to inadequate thermal contact, which I hope to rectify by drilling a small depression in the h/s and using thermal epoxy to bond the sensor in place.
 
freemanjack

freemanjack

Well-Known Member
sixstring2112 said:
So your making a dim circuit that dims the ballasts based on heatsink temps using just some type of simple temp sensitive resistor? Will there be a video on this jackson?
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yup, simple 45 pence NTC thermistor, it has a starting resistance @ say 25c of 330kohm which drops to zero as it gets to maximum temp (in this case 150c). Once I have it dialled in, in theory, if all fans fail or there is some other heat issue (excessive summer air temps etc) this simple little thermally variable resistor will do the same job as the potentiometer dimming and reduce the resistance to earth in any 10v dimming circuit. and yup, will do a full vid, including all my fuckups which are always endlessly useful to anyone following, there have been a few, no doubt there will be more.
 
freemanjack

freemanjack

Well-Known Member
freemanjack said:
yup, simple 45 pence NTC thermistor, it has a starting resistance @ say 25c of 330kohm which drops to zero as it gets to maximum temp (in this case 150c). Once I have it dialled in, in theory, if all fans fail or there is some other heat issue (excessive summer air temps etc) this simple little thermally variable resistor will do the same job as the potentiometer dimming and reduce the resistance to earth in any 10v dimming circuit. and yup, will do a full vid, including all my fuckups which are always endlessly useful to anyone following, there have been a few, no doubt there will be more.
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Bingo! get yer thermistor protection while its hot!!
 
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