Auto Fuse for power supply


Posted on Feb 15, 2013

The power supply, with electronic stabilisation - mainly those of laboratories - it should they are protected from ??over current?? that emanates from short-circuits, erroneous association or damage of repaired appliance. The circuit offers effective protection in power supply with output voltage through to 45V DC. Transistor Q3 of is type in all cases BC148, while the types of Q1-2, as well as R1-2, depend from the biggest intensity of current, according to the table. The entry is connected in the exit power supply. Under regular conditions of work, the Q2 turn on, completely via the R1-Q1 and functions in the saturation.


Auto Fuse for power supply
Click here to download the full size of the above Circuit.

The output voltage is 2V roughly lower than the voltage of supply. If grow the dip of voltage, in the R2 at 0.7V. because short-circuit, then conduct the Q3 and the voltage between the collector and his emitter is 0.3V. the Q1-2, however is driver only when his voltage between the base of Q1 and emitter of Q2 is 1.4V at least. But in case of overcharge, this voltage is 0.7V+0.3V=1V, with result the circuit is regulated automatically in the predetermined biggest intensity. The transistors that I give in the table can be replaced with corresponding, it is enough they suit their characteristics. Imax (A) R1 (?) R2 (?) Q1 Q2 Q3 5 100 0.12 2?1613 2N3055 BC148 0.5 1000 1 BC107 2N1613 BC148 0.1 4700 4.7 BC107 2N1613 BC148




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Infra-red Level Detector with 555
    Digital Thermometer using
    Simple Spectrum Analyzer Adaptor For Scopes Circuit
    More debugging of the NRI 832
    32.768 KHz Oscillator using Watch Crystal
    Simple Circuit 12V to 120V DC DC Converter
    Fire Alarm Circuit Using 555 IC
    Low Frequency Sine wave Generators Schematic
    High Quality Intercom
    IF processing - video detector circuit
    One circuit electromagnetic vibration table
    Using tap potentiometer loudness circuit



    Top