 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Electronics : Diversion/ dump load options (re-purpose)
  Page 2 of 4   |
|||||
| Author | Message | ||||
GWatPE Senior Member  Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
The most reliable windmill controller I have found is to just turn off the windmill when the voltage is 25% above the nominal battery voltage. Windmills make poor battery maintenance tools. A small PWM loading to give some battery absorbtion charge is sufficient during low wind conditions for the absorbtion phase. If the power levels increase, then just turn the windmill OFF. Large heater type loads sufficient for the maximum windmill output are expensive, and are only really useful if they provide a staged loading. Unless the voltage is varied to suit the voltage that the battery requires during each phase of recharging, then big heaters are not the answer. The loading should not discharge the battery, and should be diode blocked to prevent battery discharge. There are some very expensive proportional loading arrangements that are not good for the battery life. The best arrangement is to have a reliable automatic secondary recharging system that provides the battery maintenance phases. Gordon. become more energy aware |
||||
liqud Newbie  Joined: 11/08/2009 Location: United StatesPosts: 22 |
i have noticed that the tile you used probably cost more than a store bought dump load. jk Shawn C Real power is not given its made... |
||||
| liqud Newbie Joined: 11/08/2009 Location: United StatesPosts: 22 |
ok guys i have a slight let up on the dump load situation my brother boss went to go cut the stator out of the mold and nicked the wires so there is a big whoops. javascript:AddSmileyIcon('  ') I have a working test unit attached to a bike i will trying some bulbs on but the test rack solid wye. the new/shorted stator is manually controlled wye to delta switched. feel free to collaborate on that whole thing... but i appreciate the activity through and through.Shawn C Real power is not given its made... |
||||
| liqud Newbie Joined: 11/08/2009 Location: United StatesPosts: 22 |
Ok its been awhile. sorry about that after cannibalizing a few automotive 20 amp (in parallel) heaters i procured cheaply I have a dump load that takes out the necessary amperage needed. (the downside ladybugs love the warm weather in the project shed now) I am using a coleman air load controller. It uses a pic12f683 chip and a simple MOSFET controlled circuit to operate a few relays. I am in the process of upgrading to a new 12f675 piclogger that you all were kind enough to write up. And on that note i am leaning toward putting some mr16 lights for a more aesthetic appeal cause its still usable energy after all. I am also going to try the stainless steal approach I would like to have a t and e session to try several other methods. probably in mid december. It has come to my attention that I need a bigger project enclosure Has anyone tried using an air compressor to store excess energy to charge a smaller generator when wind and batteries are low. http://en.wikipedia.org/wiki/Compressed-air_energy_storage Shawn C Real power is not given its made... |
||||
| liqud Newbie Joined: 11/08/2009 Location: United StatesPosts: 22 |
When it comes to a back up system to stop free spin or over charging I cant put a limit on the fail safes you install. What ever i install i will gladly leave installed as future options within reason. my ax fx gene is about 2 hours south at a friends house so buying time to get there is a great idea if he cant handle it. thanks andy Shawn C Real power is not given its made... |
||||
| VK4AYQ Guru  Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi All I read with interest load dump suggestions and see it as a bit of a waste, I am working on a dump system that dumps into the mains through a 24v grid tie inverter available on ebay at reasonable proce 300/600 watts per unit and can be stacked on one phase or spread over 3 phases, and modified heating element to go into HWS 24v 25 amp. Inverters are switched on at 27.5 volt at the battery bank and heater element switched on at 28 volts.Set dropout voltage -1v below sw on voltage. Bypass switch to allow battery eql charge at 29 volts. Foolin Around |
||||
| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
There is always the possibility that during windy times that the water will get too hot and boiling will occur, and the grid may be OFF. I would still use normal automatic windmill shutdown systems. I dump to the grid with a GTI to maintain my batteries, and have all the shutdown systems as well. Gordon. become more energy aware |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Gordon I agree that murphy is alive and well, I just hate to waste precious power and contributing to global ? warming. Project for next year is a heat storage system using a 10000 gallon underground tank at 22/23 deg c nominal temp to heat and cool the house in lew of airconditioner using peltier plates and a heatexchanger to warm / cool the water depending on the season, for people with swimming pool it could be used for thermal mass. I also use an aircompressor to absorb energy driven with a old truck generator that absorbs 59 amp at 24 v and it supplies most of the air needed in the workshop. Storage is by time expired Car LP tanks available very cheaply tested to 150psi with water as in boiler test then dried out and proofed inside with fishoil or linseed oil to prevent corrosion. All the best Bob Foolin Around |
||||
KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
I got the heat capture device for you Bob 100 evacuated tubes will heat the whole house. Transport to QLD might be an issue but they are going cheap (were $8K new) and selling for $1500 as I just cannot use enough heat, I'd love to have 10,000 gallons available as I reckon that would work a treat, a hydronic system for the house and whalah free heating. only problem is what to do with all that heat, in summer you're going to have 10,000gallons of boiling water, need some kind of heat engine to convert to ..... the mind boggles and if I keep going I wont sleep tonight thinking about it.... again! Luck favours the well prepared |
||||
| readyakira Senior Member Joined: 17/07/2008 Location: United StatesPosts: 114 |
The dryer heater elements we use in our clothes dryers are rated for 4500w @ 240v and run about 30-50$ Used you can prob find one half price. GE has a re-string kit that is about $20-$30 and comes with ceramic insulators so you could easily mount them to something metal. at 4500w you could prob make a 2 and sell one off for some of the money you spent to get it. alot of house heaters only use 5k - 5.5k heaters so there is dang near enough that with a squirel cage fan you can heat your house in the winter! Don't you think Free/Renewable energy should be mandatory in new buildings? |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Karl These tubes you have sound interesting you could use them to make a heat engine or low pressure steam engine and make yourself a few KW of energy during the summer. My problem here in SEQLD is to much heat. All the best Bob Foolin Around |
||||
| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
I havent found a heat exchange engine yet that I could build or buy, forgotten what they call them ..... anyone? Steam is a no-go as steam =pressure and the tubes only good for 100KPA. If only I could adapt it somehow so fire=ice like a gas fridge, then I could use the energy from the sun to refrigerate the house.... There will be a smart cookie here somewhere that will tell me how.... Karl Luck favours the well prepared |
||||
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
They are called Stirling engines. I saw a commercial one for use as a gen set on bigger boats etc. Can't think where I saved the link address, from memory the unit was made in NZ. Klaus |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Karl Many years ago I made a steam engine for an alternat energy guy in the bush it ran of 20 psi steam I think within the pressure capacity of your tubes. The reason for this was to use a low pressure boiler that didnt need complience from government. Workimg pressure 20 PSI Condenser Vacume - 10 \Total pressure = 30 2 cylinder in 90deg V configuration Based on old launch engine design Bore: 8 inches Stroke: 6 inches RPM: 500 10 HP aprox It ran an old 250 amp lincon generator charging a huge 32 volt battery pack with a 5000 wat transverter for 240 volt but mainly 32 volt appliences lights and fridge freezer using an old car airconditoning unit. The only thing not off the shelf was the cylinder castings, made by local foundry. All things are possible if not practical. All the best Bob Foolin Around |
||||
oildependency Newbie Joined: 23/01/2010 Location: United StatesPosts: 1 |
Hey Shawn, Found a company that supplies ready made dump load resistor seems to be about $1 per amp. So a 1000watt, 83amp turbine would need 4 of these resistors which would come to $80. 12V- 300watt-Dump Load Resistor-$20 Matt Coyle ouroildependency.org zelenenergy.com |
||||
Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
KarlJ; I've been reading old posts. You may be interested in this site on solar refrigeration. Solar Time has proven that I am blind to the Obvious, some of the above may be True? |
||||
| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
I've read this post a few times she's a good read. I also see now what Gordon is talking about with the auto shutdown on his mill and I like the idea of wrapping fencing wire around a fluro tube from Tules too, would be pretty tough any way you look at it to destroy that! I can remember where I read it but someone had a formula for calculating the length required (for fencing wire), I think for 12V systems not so much of a problem but 48V systems for a dump at around 60V means much longer bits of wire! Now that I have some batts I actually can test a few things that concerned me -appears rightly so, the resistance of the heater elements increases significantly with temperature, meaning less current flow, I tried my 8Ohm dump first, and found the resistance more than doubled after a few minutes of heating...... So this throws up a few problems as the PL20 only switches 20A which should be good for 1200W at 60V but if this is the inrush current and with heat the value drops to 600W then I'll have a problem..... how many 48V relays do you find.....none, so could series 4 of them (coil side) and then parallel the outputs for say 40A current handling.... Anyway I have lots and lots of bits (and fencing wire  ) so when she's up and running I'll run some tests, turn off the inverter and see the sort of AMPS she pulls etc... Luck favours the well prepared |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Karl I bought some 25 amp AC relays on ebay solid state for about #13 dont work on DC but you could use three of them across the the three alternator leads before the caps also a dump load I ueed in the past for testing was made of SS cut into strips and spiral wound on fibro cement irrigation pipe immersed in a 60 ltr drum of waste oil all very cheap and bullet proof it would absorb several hundred amps at 120 volt DC. Vary the width and lengths of strips to alter resistance. Three such resistors would do your three phase system. All the best Bob Foolin Around |
||||
Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Karl. You could series the coils in several relays OR just add a series resistor to one relay coil and make it a 48volt relay. I think the average electrical supplyer (not electronic)that a electrician would buy parts from, stock 48 volt relays. Often used in industral applications. All load resistors will change in resistance as they get hot, even fencing wire. This is why i said to test each resistor and adjust the wire length to suit when making the element resistors. Pete. Sometimes it just works |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Karl this the relay Bob | Listed in category: Business & Industrial > Electrical & Test Equipment > Industrial Automation, Control > Relays, Timers & Counters > Relays Watch this item Sign in or Register to add your items to My eBay. Please waitImage not availableEnlarge Solid State Relay SSR 24-480V AC, 25A + Heat Sink Item condition: New Time left: 21 days 2hours (13 Feb, 201014:02:01 AEDST) Quantity: More than 10 available Please enter a quantity of $quantity$ or less Please enter a quantity of 1 Price: US $13.99 Approximately AU $15.45 Buy It NowBuy It NowBuy It Now Watch this item Now watching in My eBay Now watching in My eBay Postage: FREE postage Standard Int'l Flat Rate PostageSee more services See discounts | See all details Estimated delivery time varies for items sent from an international location Foolin Around |
||||
| Page 2 of 4 |
|||||
 Print this page |
