LF DAC Driver

This simple circuit was developed as a low-frequency (LF) signal generator to exercise a temperature control system used to control a process that can have a very large time constant (i.e., the time taken for the output to reach equilibrium after a change of input signal) of tens of minutes to several hours. The circuit can be used to test a control system out on the bench before being re-installed back in the plant, or used as part of a demonstration rig.The test circuit outputs a triangular voltage signal on K2 that ramps from zero to +5 V and then back down again to 0 V. The time taken for one cycle is dependent upon the clock signal fed into the circuit at K1.