step up converter output

Discussion in 'General Electronics Chat' started by O.K., Jan 2, 2016.

  1. O.K.

    Thread Starter New Member

    Dec 10, 2014
    19
    0
    Hi!

    I want to build a constant current source boost converter for leds. I use 34063 ic with external n fet switch. The current meassured by a 0.1 ohm resistor and this voltage amplified to 1.25 V. My question is that is this circuit safe? I mean that the output is limited or can go so high (e.g. open output) which can kill? Thanks for reply.
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,140
    1,789
    You have to look at the available power input and the available power output. Circuits with voltages under 50V DC are generally considered safe, but the details do matter. As a rule of thumb you should consider the power output to be 80% of the power input. Once your design is complete you can do a more detailed analysis of the efficiency.

    For example:
    Input power is 12V @ 1 Ampere = 12 Watts
    Output power is 12 Watts * 80% = 9.6 Watts
    Now 9.6 Watts can be 48V @ 0.2 amperes or 16V @ 0.6 Amperes or any other combination that yields 9.6 Watts

    Does that clear things up?
     
    Last edited: Jan 2, 2016
  3. O.K.

    Thread Starter New Member

    Dec 10, 2014
    19
    0
    Than you for reply.
    So will it be safe? Does the output limited (e.g. 50 V max) or should i handle the high resistance load case?
     
  4. Papabravo

    Expert

    Feb 24, 2006
    10,140
    1,789
    You need to provide some information on the power source and the circuit.
    How can we answer your question without a circuit to evaluate?
     
  5. O.K.

    Thread Starter New Member

    Dec 10, 2014
    19
    0
    The power source is 12 V from a computer psu. here is the circuit diagram:
    Névtelen.png
     
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