Fixed-Current Regulator

Posted on Oct 26, 2012

This fixed 1-mA current source delivers a fixed current to a load connected between Ql`s collector and ground; the

Fixed-Current Regulator
Click here to download the full size of the above Circuit.

load can be anywhere in the range from 0 to 14 . The circuit is powered from a regulated 15-V supply, and the R1/R2 voltage divider applies a 14-V reference to R3. The op amp"s output automatically adjusts to provide an identical voltage at the junction of R4 and R5. That produces 1 V across R5, resulting in an R5 current of 1 mA. Because that current is derived from Ql"s emitter, and the emitter and collector currents of a transistor are almost identical, the circuit provides a fixed-current source. The output current can be doubled by halving the value of R5.

Leave Comment

characters left:

Related Circuits

  • New Circuits



    Popular Circuits

    Hi-Fi power amplifier with MJ3001 and MJ2501
    Daylight alarm with 555
    Inverter circuit for florescents
    Low-pass filter
    FSP107-2PS01 two-in-one power panel circuit analysis
    measurement Measuring large differential voltage
    hall effect switch
    24v dc power supply using lm7824
    wireless headphones transmitter
    Schematic Diagram Electronic FM Telephone Transmitter Circuit
    TLE6282 H-Bridge And Half Bridge Driver IC
    USB to Serial RS232 adapter circuit design electronic project
    Trimless IF VCO: Part 2: New ICs Simplify Implementation
    One power supply circuit soft start
    Control Ladder retract mechanism work