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jonnny
New Member
United Kingdom
50 Posts |
Posted - 16/01/2008 : 13:35:17
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| hi ghurd i dont think i will see 40 amps very often if at all , but any help and advise on modifing this kit to suit my needs would be most welcome and very much apreciated thanks ,jonny |
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ghurd
Junior Member
USA
314 Posts |
Posted - 16/01/2008 : 13:54:50
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They need to be on seperate heat sinks, and have separate loads.
It does not take very much heat sink if the load stays below 6A.
Placing them on one heat sink is the same as having all the loads connected as a single load.
They could be on a single heat sink to power a single larger load, however additional precautions need to be taken with driving the fet gates. It can cause problems for the average guy.
G- |
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fungus
Moderator
301 Posts |
Posted - 16/01/2008 : 19:27:40
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Just to say I have another finished and ready to go,
Angus
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agrifabs
New Member
United Kingdom
76 Posts |
Posted - 16/01/2008 : 19:41:05
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| hi fungus, did you manage to sort mine out? eager to get my batteries charged now!! |
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fungus
Moderator
301 Posts |
Posted - 16/01/2008 : 19:45:04
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| agrifabs, posted it earlier today. |
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agrifabs
New Member
United Kingdom
76 Posts |
Posted - 16/01/2008 : 20:08:19
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| cheers mate... |
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ghurd
Junior Member
USA
314 Posts |
Posted - 16/01/2008 : 21:04:26
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Jonnny,
If it WILL make 40A, then the dump load should be somewhere around 50A.
The kit will work fine, but it will need extra parts.
Extra fets, bigger heat sinks, expensive power resistors, etc. A fan or 2 on the resistors would be a good idea.
If it were me, I would use (at least) 2 kits.
The 1st one dumping maybe 5~6A and powering the resistor's cooling fan.
The second one set at a slightly higher voltage, dumping a lot more amps. And so on, if 3 kits were used.
A 40A windmill is getting into commercial controllers that cost a couple hundred pounds. And that is Without the dump load resistors!
Fungus is a cheaper option. He understands the changes required, and can get closer figures for UK.
G-
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jonnny
New Member
United Kingdom
50 Posts |
Posted - 16/01/2008 : 22:16:05
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| thanks ghurd i will have to think it over , my turbine is not finished ,need to get on with that at the moment many thanks for your help and advise jonny |
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Del
Junior Member
United Kingdom
369 Posts |
Posted - 16/01/2008 : 22:30:06
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Hi Ghurd & Fungus,
A 40A charge controller would be handy for me with the impending 24V Futurenergy unit (It's supposed to make 34A at 24V).
I was thinking of a Xantrex unit but they cost many beer pennies and I'm naturally adverse to spending a lot on something that doesn't seem to do that much. (I am aware that they are there to protect your even more expensive battery bank from frying).
If you think that a multi-unit set up with extra fets, heat sinks, resistors and a couple of fans would work then I'd be happy to commission a prototype from Fungus Electrical Enterprises.
Would I be right in thinking the dump load(s) would be most expensive parts to dump that amount of current?
Thoughts?
Thanks
Del. |
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Mertz
Starting Member
USA
42 Posts |
 Posted - 17/01/2008 : 01:26:09
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I bought one of the kits from ghurd and am putting it together with a lot of his help. There has been a lot of talk about dump loads but nothing has been said if the the unit prevents excess battery drain. We want to keep the voltage in the battery in a certain range. I have been running my 2 mills without a controller up to now and we had some 30 mph winds with gust to 43. The battery voltage the next morning read 12.49 volts. (I have a 3 battery bank). Aren't the batteries regulating the power to some degree?
Mertz |
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speo
Junior Member
Canada
114 Posts |
Posted - 17/01/2008 : 01:54:44
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Mertz, the battery will keep the voltage down until the battery is fully charged. After that, if you continue pumping amps, the voltage will raise, the batteries will boil and their life will be shortened. That's why you need a shunt regulator.
I bought one kit from ghurd and it came with few extra resistors for configuring the hysteresis (how much the dump load will discharge the battery). "Resistor RX determines the hysteresis. The lower the ohms of RX, the tighter the hysteresis". For example, if you set it to dump at 14.20V, and you want a tight hysteresis, choose the lowest value for RX and it will connect the dump load at 14.20V, the voltage will drop rapidly, then, when it reaches 14.14V the regulator will disconect the dump load. That's a 0.06V which is quite tight. If you want a less tight hysteresis, choose a higher value for RX.
Here are some useful links:
http://www.fieldlines.com/story/2007/8/24/172521/889
http://ghurd.info/dc.html
Speo
www.windpulse.com |
Edited by - speo on 17/01/2008 02:01:37 |
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agrifabs
New Member
United Kingdom
76 Posts |
Posted - 18/01/2008 : 18:50:05
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hi fungus. recieved my regulator today and i must say that it looks good, im still awaiting my blocking diodes to arrive. just wondering what the two light indicate on the regulator? and also whats the maximumum amps and volts this regulator can cope with?
thanks
chris |
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fungus
Moderator
301 Posts |
Posted - 18/01/2008 : 19:12:49
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agrifabs:
The yellow light indicates that the unit is connected to the battery and the green light indicates that the battery is charged and it's dumping power. It's set at 14.1v for a 12v system, it should do 20-25A without too much difficulty. |
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agrifabs
New Member
United Kingdom
76 Posts |
Posted - 23/01/2008 : 19:12:01
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| hello fungus, i have connected everything up today, but the light to indicate the unit is connected does'nt light up. any ideas? |
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fungus
Moderator
301 Posts |
Posted - 23/01/2008 : 22:59:05
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agrifabs;
Checklist:
The only problem I could really see that would cause that is that either the sense wires havent been connected or that they are the wrong way round, it wont work that way and it protects itsself, check all the connections are secure too. |
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Topic |
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Shunt regulators for sale
