The first you need convert 0-50mA to voltage, then design a constant current circuit using OPAMP, so the voltage can cotrol the output current , and you need set the ratio equal to 40%. I have ever used this method.But I don't know if there is a better way.
The first you need convert 0-50mA to voltage, then design a constant current circuit using OPAMP, so the voltage can cotrol the output current , and you need set the ratio equal to 40%. I have ever used this method.But I don't know if there is a better way.
