Position: Index >

Precision Current Sink (2N2219)

2017-07-12 07:48  
Declaration:We aim to transmit more information by carrying articles . We will delete it soon, if we are involved in the problems of article content ,copyright or other problems.

This article describes the Precision Current Sink (2N2219). The content is very simple, very helpful. Components in this article can help you understand better understanding of this article. For example, in this article, you can go to find and buy these components:2N2219.

This a a simple circuit for precision current sink. This circuit uses two kinds of transistor, 2N2219 bipolar transistor and 2N3069 JFET because both of them have inherently high output impedance. Here is the circuit :
Precision Current Sink circuit schematic
To provide feedback to the LM101 op amp, this circuit uses R1 as a current sensing resistor. The true current sink nature of this circuit is enhanced because the op amp provides a large amount of loop gain for negative feedback.
The output current is given by :
Io = Vin/R1
with Vin > 0 V
The 2N2219 and the 10K resistor may be eliminated, for small current values, if the JFET’s source is connected to R1.

Reprinted Url Of This Article: