aakaash Posted October 2, 2005 Report Share Posted October 2, 2005 Yes, We have a circuit for running CFL from 12 V, it costs Rs.150, Hello,Prof.Nura100,Or just give me miss call on (0)98220 55016 or mail me on [email protected] .Aakaash Quote Link to comment Share on other sites More sharing options...
bpb Posted October 2, 2005 Report Share Posted October 2, 2005 Bravo Sasi, :-*What a long post, I'll call you Dr. Sasi :D :D Quote Link to comment Share on other sites More sharing options...
nura100 Posted October 4, 2005 Report Share Posted October 4, 2005 Hello Sasi,Your Cutoffs circuit could be further simplified, using just one Relay or Mosfet. instead of using 3 relays and bigger PCB.i have redrawn the circuit which we use in our Emergency Lights, the circuit usesall Quote Link to comment Share on other sites More sharing options...
Guest Kasamiko Posted October 4, 2005 Report Share Posted October 4, 2005 Hmm...There should be a good replacement for this age old LM324 chip..a TL may be a good choice.. ;DRhonn ;) ;) Quote Link to comment Share on other sites More sharing options...
nura100 Posted October 4, 2005 Report Share Posted October 4, 2005 Hmm...There should be a good replacement for this age old LM324 chip..a TL may be a good choice.. ;DRhonn ;) ;)So is SG 3524arun Quote Link to comment Share on other sites More sharing options...
harrychoo Posted October 7, 2005 Author Report Share Posted October 7, 2005 Wow, after having not reading my own thread for 2 weeks, it end up with so many discussions. Bravo.For Arun > Is it possible for me to get the manual or reference book for UPS? I want focus in the battery charger and sine wave inverter study. My rough spec will be 12V 7Ah SLA battery charger(might be more than 1 piece) and for inverter is about 500W or more than that. If possible, i hope the reference book can cover every spec and explanation so i can see the difference from that.And yeah, i'm from Malaysia. So anyway for me to get this?Thanks.For all>Battery chargerFor the battery charger, I would like to know more about the charging voltage, current and charging time. Is it efficient for us to use LM317 to charge the battery? As far as i know, to efficiently charge a SLA battery, we migh consider the charging voltage and temperature as well. For the charging voltage, as i know, to charge a low energy SLA, we need to use cyclic charge 1st (2.35V-2.4V/cell) until the charging current drop to a minimum value (3% of the rated current), then we have to change the charging state to float charge (2.25V - 2.3V/cell) Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 7, 2005 Report Share Posted October 7, 2005 The only pure sine-wave inverter circuit posted so far is the one with a sine-wave function generator IC feeding some linear Mosfets that drive the step-up transformer. It is extremely inefficient.All the rest are square-wave with an efficiency of about 85% to 90% at full output. Quote Link to comment Share on other sites More sharing options...
nura100 Posted October 7, 2005 Report Share Posted October 7, 2005 Hello Sasi !Today, i was just going thru your Pcbs & Schematics in this thread, i felt there were inconsist with each other. ( hold a second, Don't get angry!)what i mean is - the output mosfet section schematic shows only 33 Ohms gate resistors , but your Board shows Gate resistors + Diodes+ diode or resistors.and also in the Oscillator section, in the schematic you have shown one diode, but on the board there are a Pair of diodes.a final request, your PCBs are helpful to any member who wud like to build an inverter, so can you post the Silk screen with the Component Values instead of just Component outlines.arun Quote Link to comment Share on other sites More sharing options...
nura100 Posted October 7, 2005 Report Share Posted October 7, 2005 Pair of diodes befor the Series Capacitors Quote Link to comment Share on other sites More sharing options...
nura100 Posted October 7, 2005 Report Share Posted October 7, 2005 Sasi, I also have noticed on your Mosfet Board you have used MOVs which are not present in the Output schematic ???were these later added ?arun :) Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 7, 2005 Report Share Posted October 7, 2005 Hi Sasi,Your sine-wave inverters ar linear heaters. It is time to make them efficient with variable PWM. ;D Quote Link to comment Share on other sites More sharing options...
nura100 Posted October 8, 2005 Report Share Posted October 8, 2005 Hello Sasi,there is an error in your Controller board Silkscreen the 6 amp diodes(diode pairs) are reversely connected, they should be connected the other way round.i've circled them in the Pic. :Dhave you checked this ;)arun Quote Link to comment Share on other sites More sharing options...
chong Posted October 8, 2005 Report Share Posted October 8, 2005 Please help- cant find either Advanced Inverter & UPS Circuits or Modern Digital Inverter books. ISBN # posted is no good (tried 0 thru 9 for last digit) . I want to buy one or both. thankschong[email protected] Quote Link to comment Share on other sites More sharing options...
nura100 Posted October 10, 2005 Report Share Posted October 10, 2005 Hello Sasi :Dthe big Diodes, capcitors, 220 Ohms -high wattage Resistor, all these components are used for Protecting the Mosfets from High Voltage Stress & Spikes from the Trafo.if u are not using them correctly, the Mosfets are at risk.since you have Vol- 19 of EFY Projects, there is a PWM Inverter Construction project by Mr. Bashin, using SG 3525, the author has used simple Setup to Drive Mosfets without using BC 557s & BC 547s.the Spike protection for mosfets looks good. :DDid you try that circuit ? ???here's the Circuit ;Darun Quote Link to comment Share on other sites More sharing options...
harrychoo Posted October 11, 2005 Author Report Share Posted October 11, 2005 Hi nura100,I also want to buy some books that related to UPS design (particular in inverter and charger design) similar to what u posted before.Is it possible for me to get it?Can PM me or email me ([email protected]) regarding this?Thanks Quote Link to comment Share on other sites More sharing options...
electroman2000 Posted October 14, 2005 Report Share Posted October 14, 2005 HI to all,i have build the 500w inverter and works perfectly i tested it to see its maximum capability and deliivered almost 700w from it,also if you need it more powerful dont use 2N3055 transistors but use 2N5886 as you gain about 40% more power on the whole,i took some pictures of the inverter and is posted on my website of stages in construction and how i designed the heatsinks as the sides,take a look at it on this adress: http://inverter500.blogspot.com/ if you need help in construction im here to help. Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 14, 2005 Report Share Posted October 14, 2005 Hi Roderick,That's a wonderful monster you built and it's great that it works so well. ;DThanks for the tip about more powerful transistors.Where did you get the huge heatsinks and that huge transformer? Quote Link to comment Share on other sites More sharing options...
electroman2000 Posted October 17, 2005 Report Share Posted October 17, 2005 Thanks audioguru,well the heatsinks i made them from a piece of anuminium plate i got from a tool maker and cutted it 135mm by 135mm its thickness is 10mm,then inserted a 2n3055 in a piece of cardboard and cutted its outline with a scissors which i used as a jig to draw the transistors on the heat sinks.then i drilled the mounting h ;Doles and connection holes with a 4.5mm drillthe transformer i got it from an old plating equipment i found in a factory skip and was rated 615va.it works quite well all i had to modify in the circuit was that i installed a 7812 voltage regulator on the control board to keep stable voltage and instead of a resistor for the frequency resistor i used a pot for fine tuning of frequency.it is a litle heavy as a unit but i use it to powerr up my garage as there is no electricity where it is and made o box with abatery and a charger that i charge at home and connect it to the unit at the garage.next thing i want to add is a solar battery and a charge regulator and that would become a solar powerstation! Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 17, 2005 Report Share Posted October 17, 2005 Hi Roderick,Your inverter is smaller than it looks in your pics. ;D Quote Link to comment Share on other sites More sharing options...
electroman2000 Posted October 17, 2005 Report Share Posted October 17, 2005 Its whole dimensions are 225mm wide by 170mm height by125mm depth. Quote Link to comment Share on other sites More sharing options...
electroman2000 Posted October 17, 2005 Report Share Posted October 17, 2005 I have the modified schematics Quote Link to comment Share on other sites More sharing options...
Guest Alun Posted November 9, 2005 Report Share Posted November 9, 2005 Here's an ebook I've found about inverters, in general, it does cover sinewave inverters but it doesn't show any schematic so you'll have to figure that part out for yourself.My understanding is that there are 4 ways of designing a sinewave inverter:(1) Use a resonant transformer - simple but yeilds a distorted sinewave.(2) Build a low voltage inverter that uses a signal generator and class D amplifer to convert the low voltage AC and use a transformer to boost it to the mains voltage as audioguru was talking about.(3) Build a DC-DC converter that boosts the low battery DC voltage to a higher voltage DC than the the required output, then use a signal generator and class D amplifier to convert it to AC.(4) Use lots of transformers with their secondaries connected in series and h-bridges on the primaries to produce a sinewave with so many steps they blend together. Quote Link to comment Share on other sites More sharing options...
nitrojunx Posted November 11, 2005 Report Share Posted November 11, 2005 hi to all, could anyone share me a link in making an efficient transformer, i will be using it for my inverter, my specs are 220vac output @ 1.5Kw from 12 or 24vdc input.. thanks.... Quote Link to comment Share on other sites More sharing options...
MP Posted November 11, 2005 Report Share Posted November 11, 2005 There is some information on winding transformers in the Articles section of this site.MP Quote Link to comment Share on other sites More sharing options...
nitrojunx Posted November 12, 2005 Report Share Posted November 12, 2005 thnks Quote Link to comment Share on other sites More sharing options...
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