| 摘要 |
The invention relates to a constant source of current (1) with at least one operational amplifier which is operated at a supply voltage (UB) and which supplies a current which is independent of the connected load resistance (RL) at its output. According to the invention, the supply voltage (UB) is a bipolar supply voltage with a positive pole (+UB) and a common zero point (GND). The constant source of current has two operational amplifiers (V1, V2). An input circuit (R1, R2) connected to the supply voltage (UB) is used to produce an input voltage (UE) which is supplied to the non-inverting input of the first operational amplifier (V1). The output of the first operational amplifier (V1) is connected by an output resistance (R3) to the output (OUT), to which the load resistance (RL) can be connected. An output voltage divider (R4, R5) and a feedback voltage divider (R6, R7) are used to ensure that a constant current flows at the output (OUT) independently of the value of the load resistance (RL). The source of current (1) has a simple construction and is therefore economical to produce. The invention can be used in measuring technology. |
