Circuit function
A current source is a constant current source that provides a constant current for a load with varying resistance. The resistance (or voltage) can be measured by inputting a constant current, and the constant current source can also be used for the driving circuit of the semiconductor sensor. In this circuit, since the reference voltage is connected to the power supply, it is difficult to control with an external voltage, so the current is adjusted by the variable resistor.
Circuit working principle
In order to understand the working principle of the circuit, with +VCC as the reference voltage, the input voltage of the OP amplifier A1 cannot be near +VCC, so reduce it by about 5V, so that the non-inverting input voltage is about 10V, then the inverting input of V1 is required. The voltage should also be around 10V. The voltage generated across R4 is controlled at 4.7V, so that a constant current of IO = 4.7V / 470Ω = 10MA flows. The function of the variable resistor VR1 is to fine tune the output current IO to exactly 10MA.
The P1 FET is used for TR1 in order to make no error in the base current of TR2. It is easy to understand the gate current of the FET as zero.
Our banknote handling machines mainly include following
BC -30: basic piece counter with only one UV
BC-35: piece counter with UV MG
BC-40: value counter with one CIS, support 4 currencies, Auto recognition, multi-currency mix counting
BC-55: value counter with two CIS, support 40 currencies at the same time, serial number reading, Auto recognition, multi-currency mix counting, remote software upgrading via network
Those 4 models have similar structure, passage can be opened from reat side, easy for maintenance and cleaning
BCS-160: 1+1 pockets banknote sorter with two CIS, support 20 currencies at most, serial number reading
Euro Banknote Sorter,1+1 Pockets Banknote Sorter,Two Pockets Banknote Sorter,Banknote Sorter
Suzhou Ribao Technology Co. Ltd. , https://www.ribaoeurope.com