12vac cutoff/filter

Discussion in 'The Projects Forum' started by suhashegde, Aug 11, 2014.

  1. suhashegde

    Thread Starter New Member

    Aug 11, 2014
    2
    0
    hello,

    I am new to this forum. And i know nothing about electronics. But i have a friend who knows about electronics but doesn't know good english .

    The problem is with a halogen power source (12vac 100W) dimmable. It is a transformer based system to convert (230v). The problem is when the mains shoots up to 260v+ , the output is 13+. When the power is in the range of 220 to 240 , the output is 11.8vac to 12.1vac.

    The dimmer used is a fan dimmer. The output ranges from 3.5vac to 12vac in normal condition.

    Is there a circuit to regulate the output to under 12 when there is a increase in mains (260+). Like the output must never exceed 12vac, but must be dimmable ?

    Any links , circuit schematics, Ideas are welcome.

    Thanx in advance
    suhashegde
     
  2. Ramussons

    Active Member

    May 3, 2013
    557
    92
    A fan dimmer is not a Regulator. It gives a percentage of the input voltage that can be varied over a range. When the input varies, the output will also vary.

    Does the Halogen Lamp (must be a lamp I think) require AC? I think DC should also work (others can give a clarification pls). In which case, a Regulated DC supply (from a recovered computer PSU ?) should do the job.

    If AC is a must, then for a steady voltage, you must have a AC voltage regulator. Either a Servo stabilised AC Regulator or a 12 AC Invertor.

    If a Range of AC voltage is acceptable, use a commercially available AC voltage "regulator" used in Refrigerators or AC's
    that will ensure that the input voltage to the power supply does not go above 240.

    Ramesh
     
    Last edited: Aug 11, 2014
  3. suhashegde

    Thread Starter New Member

    Aug 11, 2014
    2
    0
    Ramesh,
    yes it is a lamp.
    And It is mentioned it needs AC.
    the problem occurs when there is a power failure and the Inverter switch on.

    Is the voltage in specified limits if i use a sabilizer for the fridge when the mains is from Inverter ?

    Thanx for your reply
    suhashegde
     
  4. Ramussons

    Active Member

    May 3, 2013
    557
    92
    Any good invertor should give a stable output voltage over a varying load. It should not require any external "regulator". The Invertor output maybe wrongly set. It should be possible to Trim the output voltage to your requirements.

    The "regulator" will be neeeded only when using Mains.

    If the Halogen Lamp is a "Filament" type, it will work on DC too.

    Ramesh
     
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