I am using this circuit to supply current through R1 which is a 50Ohm coil. Opamp is Lm124 supplied as shown in the schematic. Vin is a voltage that can be between 2.5V and 3.5V. Everything works fine except when Vin is between 2.8V and 3.1V. In this case the output of the opamp gets really noisy with constant noise exceeding 500mV which makes measuring the output voltage with an adc impossible. Did anyone encounter something similar or sees where the problem is? I already changed the opamp and checked all connections and everything seems to be fine. A 100pF capacitor over 100k reduces this but it is far from enough. Does anyone know other circuits that could achieve this voltage dependent bidirectional current through R1?