Guest Simon B Posted December 15, 2005 Share Posted December 15, 2005 I have seen reference to a 12 volt stabilizer either on here or in MMM. I believe it puts out 12 volt whatever the battery output is. Does anyone know where I can buy one of these ? I`ve tried numerous searches with no success Link to comment Share on other sites More sharing options...
Guest Doug King Posted December 15, 2005 Share Posted December 15, 2005 Hi Simon Try www.amperor.co.uk I think they have are what you are looking for. Doug Link to comment Share on other sites More sharing options...
Guest David Powell Posted December 15, 2005 Share Posted December 15, 2005 Hi Simon, try Maplins and have chat with one of their technicians. If you need it for an LCD TV, I doubt if it will work,they are very very fussy about their 12 volt supply. You may find you will need an inverter to put your battery power up to 240 volts then cut it back to 12 volts with the equipment supplied with the LCD TV. That may not be what you are after a steady 12 volt supply for, I may have jumped the gun, best of luck anyway. Link to comment Share on other sites More sharing options...
Guest David Powell Posted December 15, 2005 Share Posted December 15, 2005 Hi Simon, try Maplins and have chat with one of their technicians. If you need it for an LCD TV, I doubt if it will work,they are very very fussy about their 12 volt supply. You may find you will need an inverter to put your battery power up to 240 volts then cut it back to 12 volts with the equipment supplied with the LCD TV. That may not be what you are after a steady 12 volt supply for, I may have jumped the gun, best of luck anyway. Link to comment Share on other sites More sharing options...
Guest Clive Posted December 15, 2005 Share Posted December 15, 2005 A small inverter to generate mains voltage allowing you to use the mains power supply module suplied by the screen manufacturer is less likely to compromise your warranty should the screen fail. Plus a small inverter from Maplin will cost less than one of these 12 volt stabilisers as suggested above listed at £39.00. Both systems using switching techniques so losses will be similarly small in both cases. C. Link to comment Share on other sites More sharing options...
Guest Petec Posted December 16, 2005 Share Posted December 16, 2005 No voltage stabilser will keep the output voltage at a higher value that its input A 12V Tv normally runs on 12V DC So a 12V battery will supply the correct supply for your TV That is untill the battery has discharged to a voltage that is unacceptabe to run the TV No stabiliser or inverter can restore this voltage You will then need to reharge the battery The normal Zig charger should supply a stable enough supply bearing in mind that you are drawing current from THE BATTERY Having said that why dont you just plug into the normal mains sockets Link to comment Share on other sites More sharing options...
Guest J Turvey Posted December 16, 2005 Share Posted December 16, 2005 Not wishing to offed but only to add to the debate. Its not quite ture that "No voltage stabilser will keep the output voltage at a higher value that its input" There are indeed devices such as the Schaudt 12volt Booster WA1214-8, this device lifts any input voltage from about 10volts DC if I recall correctly to 14.2V DC. It services the correct charging of a second battery [domestic ]independantly of what the vehicle's alternator voltage regulator is doing in response to the state of the starter battery. Presumably it has its own inverter and rectifier Ther used to be an excellent UNI-charger that did much the same to transfer charge from a starter battery to the domestic battery. Saddly no longer available. Link to comment Share on other sites More sharing options...
Guest PeteC Posted December 16, 2005 Share Posted December 16, 2005 Well Mr Turvey Someone has not only the answer to perpetual motion but also to super-super conductors To be able to get more out of a device than has been put in I know you can use a transformer to bring a 12V AC up to 230V AC However to do this you must put in a larger current at the 12v end than you can get out at the 230V end in theory IV (in) = IV (out) {Less internal losses} Transformers are approx 80% to 90% efficient Inverters can be about 80% The 20% or so is lost in the windings - components & given off in the form of heat Link to comment Share on other sites More sharing options...
Guest Simon B Posted December 16, 2005 Share Posted December 16, 2005 Many thanks for all your replies. I`ll have to try and squeeze an inverter in with the two batteries under the seat! Link to comment Share on other sites More sharing options...
Guest Clive Posted December 16, 2005 Share Posted December 16, 2005 Sorry peteC but you are not quite correct. Modern inverters and even switch mode voltage regulators are in effect solid state choppers that chop the DC to make it AC. This AC is then applied to a small high frequency ferrite cored transformer to produce a higher voltage. This higher voltage is then rectified, smoothed and regulated to achieve the required output if its a regulator. If its a mains inverter it is further alternated at 50 cycles per second. But you are correct insomuch that there is no such thing as perpetual motion. Watts in = watts out less the losses of conversion. So ignoring losses, if 12 watts at 12 volts is required an outpout current of 1 ampere will be taken. But if the battery is very much discharged and has a voltage of only 10 volts the input current to the regulator will be 1.2 amperes. Shall I go on ? C. Link to comment Share on other sites More sharing options...
Guest Derek Uzzell Posted December 17, 2005 Share Posted December 17, 2005 The technical data for the Schaudt 12volt Booster WA1214-8 that J Turvey mentions includes the following: Input voltage: 11.0V - 14.5V (max. 10.5A) Output voltage: 14.2V As the unit's sole purpose is to provide a stabilised 14.2V supply, presumably it does. (Cost is about £85) Link to comment Share on other sites More sharing options...
Guest Dave Newell Posted December 17, 2005 Share Posted December 17, 2005 LCD TVs are the most common reason for wanting a 12v regulator, typically they take a couple of amps. The Schaudt unit may well give 14.2v output from as little as 11.0v input but that wasn't what Simon B wanted. One of these Schaudt units, while indeed a miraculous piece of equipment, would almost certainly cause untimely demise of a LCD panel requiring 12v. I'm sorry Clive but I do have to disagree over the inverter-mains power unit route. I do understand your argument about the manufacturers power supply being the best but not only is your method inneficient (converting nominal 12v DC to 240v AC then converting it back to a regulated 12v DC) but cheap inverters don't give anything like a sinewave output. I recently checked one on a scope and it didn't even qualify as a waveform, it was just a series of alternating spikes. Inductive loads such as transformers run a lot hotter than normal on such a supply and therefore their life expectancy can be dramatically reduced. Switched mode power supplies don't like such a waveform either. A good quality inverter that gives a near to true sinewave would be ok but they are a lot more money. I would personally hold out for a 12v regulator capable of handling the required current, it's output should be every bit as good as the manufacturers supply unit. Reagrds Dave. dave@davenewell.co.uk Link to comment Share on other sites More sharing options...
Guest Simon B Posted December 17, 2005 Share Posted December 17, 2005 Further to my last post, I went on the amperor website suggested by Doug King. One of their 12v stabilizers is designed to work with the Digifusion LCD TV I`ve just bought. Yes it is more expensive than an inverter, but this is the only item of `240v` equipment I`m likely to use when not on mains hookup. Incidently the TV came from John Lewis - £199 with 5 year guarantee and free delivery. Picture is good, but the sound was a bit tinny - I`ve now improved this with the inbuilt 5-band equaliser. Link to comment Share on other sites More sharing options...
Guest Clive Posted December 21, 2005 Share Posted December 21, 2005 Hi Dave, I only just spotted your reply while looking for something else. The mains adapters for most laptops, TV,s etc do not use any mains frequency transformers at all. The rectify the incomming supply directly and then roughly smooth this with a largish capacitor. So the incomming waveform is un-important. This unidirectional voltage across the resevoir capacitor is then chopped at an ultra-sonic frequency by a solid state inverter where the duty ratio is regulated to achieve the required output voltage. This is why the manufacturers are able to sell these power supply modules that are capable of operating on a voltage range typically of 100 - 240 VAC as indicated on that for my flat screen and also my Toshib Laptop. The low cost "modified sine wave" inverters do as you state not provide anything like a pure sine wave. I have scoped two such units, a cheap one from Maplin and an expensive unit made in Canada. Both prodused rectangular waveforms, a square wave with gaps in it during the cross over period. When using one of these inverters the peak voltage is actually less that would be provided by a pure sine wave inverter, hence when connected to a TV or Laptop power supply module the voltage retained by the resevoir capacitor will be less. Consequently the power supply module will in effect be operating at a reduced voltage. This means that the small ultra-sonic inverter insude the power supply module will actually be taking a higher current and thus getting a bit warmer due to switching and copper losses. But don,t forget, these units are designed to run down to 100 volts to suit the American 110 volt market, so they have plenty of capability in hand. Good luck with the quest, Link to comment Share on other sites More sharing options...
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