The Simple Bilateral Current Source Circuit Diagram will produce the current relationship to within 2% using 1% values for Rl through R5. This includes variations in Rl from 100 ohm to 2000 ohm. The use of large resistors for Rl through R4 minimizes the error due to Rl variations. The large resistors are possible because of the excellent input bias current performance of the OP-08,.
Simple Bilateral Current Source Circuit Diagram