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  • Harshad Italiya
    Harshad Italiya

    @harshad-ukH5ww • Aug 1, 2011

    shrutzhow do i design a 12V voltage regulator circuit using ic with current rating upto 45mA?
    which ic is most appropriate for this?

    LM7812 is Suitable to your requirement.

    Datasheet for LM7812 :- #-Link-Snipped-#

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  • shrutz
    shrutz

    @shrutz-u8EnEU • Aug 1, 2011

    i tried to implement the circuit using the ic LM 7812 and was getting 12V but the current was exceeding 60mA.... so how can the current be reduced? is there any alternative to this or the design needs to be modified? if so please suggest the way....

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  • narayana murthy
    narayana murthy

    @narayana-z4W16q • Aug 1, 2011

    shrutzi tried to implement the circuit using the ic LM 7812 and was getting 12V but the current was exceeding 60mA.... so how can the current be reduced? is there any alternative to this or the design needs to be modified? if so please suggest the way....

    hey why can't you use some resistance in shunt so current will be decreased

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  • shrutz
    shrutz

    @shrutz-u8EnEU • Aug 1, 2011

    but then power loss will be more..... isnt there any alternative ic for this purpose?

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  • Ramani Aswath
    Ramani Aswath

    @ramani-VR4O43 • Aug 1, 2011

    shrutzbut then power loss will be more..... isnt there any alternative ic for this purpose?

    Do you want a constant voltage or current? You cannot have both. At 45 ma and 12 volts the circuit resistance will be 266.7 ohms. If your resistance is less than this you will get a higher current.

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  • Harshad Italiya
    Harshad Italiya

    @harshad-ukH5ww • Aug 1, 2011

    bioramaniDo you want a constant voltage or current? You cannot have both. At 45 ma and 12 volts the circuit resistance will be 266.7 ohms. If your resistance is less than this you will get a higher current.

    Have a look at above Reply, Let us know what you need constant Voltage or Current?
    this 7812 Gives you Constant Voltage and Current will be changed according to load but it gives maximum of 1A.

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  • shrutz
    shrutz

    @shrutz-u8EnEU • Aug 3, 2011

    what about the power rating? if i want to implement the ckt and make it to work for 24 hours continuously.... will the circuit get damaged?

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  • Ramani Aswath
    Ramani Aswath

    @ramani-VR4O43 • Aug 3, 2011

    Can you damage something by using it at less than 5% of its rated output?

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  • Harshad Italiya
    Harshad Italiya

    @harshad-ukH5ww • Aug 3, 2011

    Are you talking about Power Heating? Then its depend on Input voltage you applied to 7812.

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  • narayana murthy
    narayana murthy

    @narayana-z4W16q • Aug 4, 2011

    but i got some thing in this discussion
    as per my knowledge when it is open or using any heat exchange agent with air we can solve any heat problem
    so forget about heat develop

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  • shrutz
    shrutz

    @shrutz-u8EnEU • Aug 7, 2011

    hey please can anyone tell me about the input current range required for 12v lead acid battery?

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  • Harshad Italiya
    Harshad Italiya

    @harshad-ukH5ww • Aug 8, 2011

    shrutzhey please can anyone tell me about the input current range required for 12v lead acid battery?

    Do you want to charge that Battery? If you are applying more current then it will charge up in short time if less then it will take more time. remember voltage should be higher then Battery voltage.

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  • narayana murthy
    narayana murthy

    @narayana-z4W16q • Aug 8, 2011

    godfatherDo you want to charge that Battery? If you are applying more current then it will charge up in short time if less then it will take more time. remember voltage should be higher then Battery voltage.

    but here appears one thing when the voltage is higher rather charging in short time it damages the battery as per my knowledge
    so giving time is my suggestion

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  • shrutz
    shrutz

    @shrutz-u8EnEU • Aug 8, 2011

    yes. if i want to charge the battery, how much input current is required?

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  • Ramani Aswath
    Ramani Aswath

    @ramani-VR4O43 • Aug 8, 2011

    shrutzhey please can anyone tell me about the input current range required for 12v lead acid battery?

    Lead acid battery charging current is 10% of the Amp hour capacity of the battery. A 100 amp hour battery needs 10 amps charging current.

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  • shrutz
    shrutz

    @shrutz-u8EnEU • Aug 9, 2011

    thanks....

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