Fatboy Posted March 25, 2014 Share Posted March 25, 2014 Using the same forumla that the Wind Turbine Companies seem to have which is ignore the cost to install, run, service and eventually remove... If they manage to generate a couple of watts, they are deemed planet savers. I've built a 4.6 V8 110, running on Megasquirt... and fitted a SPAL fan on the front of the radiator that looks like its come off one of the everglades swamp boats (actually it was from Nige - 'nuff said ). I fitted a two-stage temp switch in the bottom of the (again, ex-Nige) Spud Cutter radiator and wired this to switch the fans on, with indicator lights on the dash for both temps. I've also got a manual "swamp boat fan 'on'" switch.. Now, the Eureka bit is that when I get up to a reasonable speed, the spinning of the fan looks like it generates enough power to light my indicator lamp up! Thus, the 110 is actually generating "renewable" power! . On one hand I appreciate I could probably take it to Dragons Den but I'm a shy kinda fella and don't fancy the fame so I'd rather figure out a solution to keep the lamps off.... I'm thinking that maybe a diode in the positive supply to the fan may be a solution but that level of electrickery is beyond my level of comprehension... So I'd appreciate any advise or alternative solutions... Thanks! PS If anybody else fancies taking my renewable power concept and running with it, be my guest Quote Link to comment Share on other sites More sharing options...
Maverik Posted March 25, 2014 Share Posted March 25, 2014 Donald, funny you should mention this, as I've got my mondeo fan hooked up to one of those Td5 type push button switches and at night if cruising at 50+ I've noticed the indicator LED lighting up when the fan isn't on, suggesting the fan is generating enough current to power the circuit in reverse... very interesting indeed... Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted March 25, 2014 Share Posted March 25, 2014 Those fans are pretty high current so it would be one beefy diode. Am sure there will be a better solution than that, are the fans switched via a relay? Quote Link to comment Share on other sites More sharing options...
Fatboy Posted March 25, 2014 Author Share Posted March 25, 2014 The main power with dash over-ride is via a relay but it then goes via the temp switch. I'll need to double check because I remember having to do some wire knitting to ensure the fan / lights were coupled but isolated from each other.. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted March 25, 2014 Share Posted March 25, 2014 If you can do a back of a fag packet style sketch of the wiring setup then I'm sure one of us will come up with a suitable scheme for you to solve the energy crisis Just draw it out rough, take a photo of it and post it up here. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 25, 2014 Share Posted March 25, 2014 A diode in the lamp feed wouldn't need to take quite as much current Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted March 25, 2014 Share Posted March 25, 2014 At the risk of going OT... As someone employed as part of a windfarm project just off the Welsh coast, I have to say it is absolutely staggering the waste and inefficiency of the entire operation. Something that was mirrored in my experiences in the humber estuary and out in the German sector last year. I think they should be turn upside down and use the tide instead. It's predictable and powerful. Back to the question - the current driving the fan wouldn't go via the diode. It'd only be passing current for the indicator lamp. At least if my assumption of your wiring is correct. Only a small diode would be necessary. Of course you could keep it as an indication that your fan motor is still OK and your fan is free to spin. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted March 25, 2014 Share Posted March 25, 2014 Best to wait till we see diagram to be on the safe side, I can imagine at least one wiring scheme where a diode in the indicator bulb supply wouldn't work. Quote Link to comment Share on other sites More sharing options...
Fatboy Posted March 25, 2014 Author Share Posted March 25, 2014 Here is the diagram and in the process of drawing it out, I suspect I see the easy solution... This setup was to allow auto switching or manual override with lights to tell me what the temp is like (okay, Amber or red). It's the amber light that comes on when the fan is generating power.. If I take the cable from T2, disconnect it at the "junction" and connect at the "Pilot in" to the relay that should do the trick. It also has the benefit that the temp switch doesn't have to deal with the full current to the fans.. The downside of that is that I no longer have the light which confirms the fan is definitely getting power (I've had a relay fail before and the pilot was saying "on" but it wasn't switching). Thoughts? Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted March 25, 2014 Share Posted March 25, 2014 That should do the trick and be nicer to the temp switch. If you must have a light to prove the relay is working you would once more need a big diode in the fan supply after the light so as to prevent it lighting from a generating fan. I'm sure FF or TRE will come up with an alternative idea if there is one. Quote Link to comment Share on other sites More sharing options...
LamontReimann Posted March 27, 2014 Share Posted March 27, 2014 If you can do a back of a fag packet style sketch of the wiring setup then I'm sure one of us will come up with a suitable scheme for you to solve the energy crisis Just draw it out rough, take a photo of it and post it up here. It is not so easy to solve energy crisis..One solution is to use less energy:) Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted March 27, 2014 Share Posted March 27, 2014 I badly want to make some smart comment about LEDs being diodes so 'can't you sort it out using the led itself' sort of thing but I got to bed far too late last night so I'm a bit brain achey. Also Donald did your springs turn up? Quote Link to comment Share on other sites More sharing options...
Fatboy Posted March 27, 2014 Author Share Posted March 27, 2014 Oops! Yup, springs turned up today thank you. Don't know how to sort with diodes or LED config as the power needs to flow in the same direction in either case... Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted March 27, 2014 Share Posted March 27, 2014 When the fan starts generating power does it generate a positive voltage or a negative one? Think it would depend on which direction it was being spun, if you were lucky and it was generating a negative voltage you could get away with an LED (with series resistor) across the fan and it would only light up when it had power applied, you could use a bulb with a smallish diode in series if you didn't like LEDs. Quote Link to comment Share on other sites More sharing options...
Fatboy Posted March 28, 2014 Author Share Posted March 28, 2014 Barry, Sorry I didn't mention this last time, I didn't think - The lamp on the dash is an LED, it is one of the little button sized indicator lights from VWP. It is sensitive to which way round it's fitted so I assume the fan must be generating positive voltage? Donald Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted March 28, 2014 Share Posted March 28, 2014 Yes it will be because the direction of airflow is the same (into the engine bay) so the fan will spin it's normal direction Quote Link to comment Share on other sites More sharing options...
bill van snorkle Posted March 30, 2014 Share Posted March 30, 2014 Don't know nuffink about diodes and stuff, but installing Stirling Cycle hot air engines inside all the Parliaments of the world should go a long way to solving the so called global energy crisis. Heck if we had one in Canberra this past disgraceful week it would have powered the whole of the southern hemisphere on its own. Quote Link to comment Share on other sites More sharing options...
steve b Posted March 30, 2014 Share Posted March 30, 2014 :hysterical: couldn't agree more Bill , as for the post Q , it's something I first noticed many years ago , and decided I could live with it as it sort of confirms things are ok with the fan motor. Right now I haven't had a engine driven fan or electric on my 200Tdi 109 for over 4 yrs and had no overheating problems cheers Steveb Quote Link to comment Share on other sites More sharing options...
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