INCREASING THE TIME CONSTANT OF A THIN-FILM MULTIJUNCTION THERMAL CONVERTER FOR LOW-FREQUENCY APPLICATION

For the purpose of optimization of the PTB thin film multijunction thermal converter (MJTC) for low frequency application, a thermal mass is added to the heater area in order to increase the time constant of the MJTC from 30 ms to 3 s or more. An obelisk of silicon remains underneath the heater during the anisotropic etching process in which the silicon underneath the thermocouples is removed. The low frequency ac-dc current transfer difference is reduced from 350 x 10(-6) to less than 1 x 10(-6) at 10 Hz.