The current from 4mA to 20mA is widely used in industry-standard field to transmit analog signals, but the traditional current source is highly sensible to temperature, supply voltage and other factors. The use of microprocessor technology for current source overcomes these shortcomings, which has such characteristics as a simple external circuit, smaller interference, inexpensive, automatic controlling, etc. Thus it greatly improves accuracy and working speed of the traditional current source.
This subject based on the single-chip AT89S52 as the core controlling unit, then designed a PWM wave modulation output signal, which passed RC filter circuit, V / I conversion circuit signal processing, finally achieved the standard current output for industry applications.
This subject passed debugging and system simulation. Also corrected software algorithms assured output signal stability, higher accuracy of mission objectives, and at the same time a certain load capacity.
