The real story behind this change, of the PSC-series is a process that Switch Craft started some years ago, with the PSC600-series!
The PSE and PSC600 use so called planar transformers, which are basically printed circuit boards PCB with windings. Due to the production process of the PCBs, it has limits on how many turns you can make. That also limits the possible input/output voltage combinations. As we have seen more demand on high input voltages and also output voltages like 110 V the planar transformers become the limiting factor. There are tricks to handle that but it takes time in pre-test and also affect the efficiency and filters of the unit, thus the EMC.
The PSC and PSC600-series has the same “infrastructure” with one primary board that has an insulated internal DC/DC converter that supply the primary drive circuit and the second board which is the regulation board with alarm and some options. It handles also the front panel LED, Pot and measurement points.
By changing the topology from Push-pull (Polyamp first in world with series produced 1974) to Full bridge on the PSC600 we doubled the voltage capacity. The insulation stage in the primary board is crucial for the full bridge topology. You might have noticed that the PSC600-series has both high input and output voltages. In the PSC600 the planar transformers are large. As we are in details, currently the PSC600 use both Push-pull and Full-bridge depending on input voltage.
Push-pull principle schema
Full-bridge principle schema
With the PSE-series we could not get the same “hedge” and therefore we stick to the original Push-pull design however we improved the yield of the planar PCBs by avoiding higher input/output voltages.
PSC has a traditional winded transformer and we used two transformer sizes, one large for the PSC “10TE” and we have a smaller for “8TE”, 50 – 80 W units (for old designs still in use). This small transformer responded very well and we can easily supply 240 W.
That fact made Mr Terranova trying to case everything in the “8TE” case, which he succeeded. Since the summer 2016 most PSC “10TE” we sold used the new board, so actually this design has been delivered for a while. In this process, new components and methods has been used, which increased the efficiency so in general we have 20-30% less losses.