Equilibrate one degree of good, electric current and is chosen the range the wide equilibrium to flow to export the circuit permanently
Function of the circuit
This circuit has electric current source and transducer two kinds of outputs, balanced degree of good oneses the source flows permanently. Under the condition of the extra 0~10V voltage, can choose the electric current on a large scale. Can use as function generator, a part of the wave form generator circuit.
It input 0~010V circuit input terminus and 0 until – 10V input terminus two cycle. One of them can be simply regarded as and put adjustment is input and used.
Circuit operation principle
OP amplifier A1 and A2 inputs being unipolar to change and equilibrate the circuit appearing in differential motion input of one degree of a good ones, they turn the input of 0~10V into 0~1MA and export B =10V, R1, R2 partial pressure, the electric current is decided by RO, RO =5K, it enlarges the resistance of the multiple in order to select ,If R7 =R2, the voltage that that not R7, R2 both ends produce will have been equal to, namely:
While demanding to produce the asymmetric wave form, so long as make R7 not equal R2, VC1 does not equal VC2. Can also be used for producing the sawtooth wave.
OP amplifier A3, A4 is a kind of symmetrical circuit, it is the power of basis to adopt 10V and – 10V separately, can get I =VC1/R11, I-=VC6/R12electric currents invariable,if it if you can’t carry on by range on electric current, switch overs to need, so long as change by resistance R11 and the hindering values of R12 or change by V0.
If R11 regards 10 times as the unit to switch over in 20,000 Europe in 200 Europe, VC1 =1V, can get I =5MA, the invariable electric current of 500UA is exported.
Choice of the component
In the invariable electric current source, in order to reduce the electric current error, should use FET input OP amplifier. The transistor selects the electric current magnifying power HYE big products for use, enable IO