39. A closer look at the FB module
discussed in picture 22.
Unlike the FM module on SAM, the MOMA design uses a self-resonant AC drive oscillator for the filaments instead of driven DC. This approach saves space and also reduces power. In many ways, this technique represents a "back to the future" since this technique was used in the late 1960's and early 1970's before being supplanted by other methods. Improved parts and an improved control approach has made this method useful again in the 2010's!