Balanced constant current output circuit with good balance and wide current selection range

OP amplifiers Ai and A are circuits that turn a unipolar input into a well-balanced differential output
. They turn the o~iov input into an O~1mA auxiliary output (set. year
iov, divided by R1 and Rz ., the current is determined by C, R=skC2, which is
the resistance of the selected magnification), if R=skC2, then under R, the voltage generated at both ends of crown l
will be equal, that is, t
    . R. R
    qmineej= -·R7! vc2剰一·chu'
    vd When vc
    requires the generation of asymmetric waveforms, as long as R, ≮R,, rD, special vczaIl
can also be used to generate sawtooth waves.
    OP amplifies As, 4. It is a symmetrical circuit. Using ten 10V
and - ioV as the reference electric probe respectively, we can get
the constant current of ten = Va,/R,,, I-='r,er/Rlz_. If we want to carry out the current range To switch, just change the resistance, 礤
chu, change the resistance value j 彘 of voa
    like Ri. by. Switching between 200Q ~ 20k0 in units of 10 times, vci =
iv r. ,,, we can get the constant
current output of f+=smA, 500 LrA, 50UA f, -Il .