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  1. #1
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    Schematic of a DC-DC converter (150-200mA)

    Hi,

    I need a schematic of a DC-DC converter (isolation converter) of some 150-200 mA of an output of +12V and -12V.

    Thank you.

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    uc3842 dc dc isolated

    Hi hayder78,

    such a converter can be built with an LM2577 from national. Use it in flyback configurtion. Look at the datasheet for examples. National has also a software to calculate such converters (SimpleSwitcher).

    Bye



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    ti isolated dc dc conveter 24v

    hi mr_ghz,

    thank you for your reply,

    i need an isolated system in which the input is electrically isolated from the output , the LM2577 doesn't provide isolation, any other suggestion?



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    flyback isolated converters discrete design

    Hi hayder78,

    An isolated system has to be built with a transformer. A DC/DC converter in an isolated configuration is a flyback converter. The input voltage is 'hacked' and sent to a transformer. It can move it to other levels (up or down) or even create more than one output voltage. One of these outputs is measured and the feedback path is often done by an optocoupler.
    Such a system can be built with the LM2577. I give you an application note: http://www.national.com/an/AN/AN-777.pdf

    Bye



  5. #5
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    lm 2577 application notes

    hello
    Is there a solution with a new IC and a transformer that we can buy transformer from an well known international company.

    I do not have time and experience for building such transformers for a specific IC (Like as TI,Lnear tech ,Maxim,analog devices IC)

    DC DC solution = IC from above company+ Transformer specified for that IC.

    any help???



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    traco dc/dc schema

    Hi 7rots51,

    Is a complete (monolithic) DC/DC converter too expensive? What are your power requirements / output voltages?

    Bye



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    dc/dc на uc3842

    hello
    I need a dc-dc converter that convert 10-30VDC(unregulated ) to 5VDC and output current can be between 200-400mA.and 1000VDC isolation at minimum.

    Can you introduce some vendors at good prices?

    Regards



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    isolated dc dc converter 500v

    Hi 7rots51,

    Traco Power (www.tracopower.com) has many DC/DC converters that meets (nearly) your requirements. The type TED2411 has an input range from 18..36VDC, an output voltage of 5V and 400mA. But the isolation voltage is only 500V. There are other types with higher isolation, but smaller input-range. But perhaps you'll find something.
    The prices depend extremly on volume you need. Other manufacturers are Powerone, Artesyn, Power Innovations.

    Bye



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    5v dc to 1000v dc convertar ic

    Don't forget Texas Inst. (formerly Burr-Brown)
    Them have a lot of isolated DC-DC with built-in transformer
    up to 1 A and isolation up to 7kV
    Sample price - approx.15-20$
    for a few kilo - approx 5-7$.



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    online tools for designing isolated flyback dc-dc

    Can we use any transformer with high freq (as used in radios) to isolate the main spikes ? Does anybody have schematics with simple components?



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    dc to dc ocnverter with uc 3842

    I think that if you have no experience about Dc/Dc converter, the best way is to start with a complete (monolithic) DC/DC converter as suggested by mr_ghz.
    The parameter to know are:
    -the range of input voltage (normally thi ranges are standard; for example 18-36V)
    -the voltages and the relative output currents
    -if it is necessary the isolation between input and output
    An important parameter to consider is efficiency. Normally for the integrated Dc/Dc Coverter it is around 80%.
    There are many manufacturers (Powerbox,Gaia,etc.) that propose their monolithic Dc/Dc Converter and some of them are cheaper especially if they come from oriental market like YDS.
    Normally the integrated solution is much more expensive than a discrete solution, but for testing your project is better to have a reliable power supply.

    In a second momet you can try to reduce the cost of your application either designing the Dc/Dc Converter by yourself (if you have time!) using the tools that many manufacturers make available on the net, like WEBENCH Tool by National Semiconductor, or you can ask third party to design and to realize the sample with your specification.

    If you need the Dc/Dc Converter only for a project the best solution is the monolithic one.
    If you need the Dc/Dc Converter for a market product the cheaper solution is the secod one.

    Best Regards



  12. #12
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    traco power orcad model

    most low cost dc-dc use uc3842 to design with flyback topology,the isolate can use transformer to realize it,because this design is complex,So you should to find a uc3842 application for it.
    www.ti.com have much application about it



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    lm2577 flyback

    anyone can help me with dc-dc buck boost converter...
    input = 12V
    outpuyt = 24V

    i need the schematic design (orcad) and the components specifications...

    thanks....