The real story behind this change of the PSC-series, is a process that Polyamp started some years ago, with the PSC600-series!
The PSE-series and PSC600-series use so called planar transformers, which are basically printed circuit boards PCB with windings. The advantage is that a planar transformer type becomes thinner and easier to cool. E.g it makes the PSC600-series possible to have 600W in a 38 mm conduction cooled case. Also the insulation system becomes easier. However 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 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. We prefered a more straight forward solution of EMC reasons.
The PSC-series and PSC600-series has the same “infrastructure” with one Driver board that has an insulated internal DC/DC converter that supply the primary Drive circuit for the power semiconductors and a second board which is the Regulation board with alarm and some options. It handles also the front panel LED, Pot and measurement points.
Push-pull principle schema
By changing the topology from Push-pull (Polyamp first in world with series produced 1974) to Full-bridge on the PSC600-series we doubled the voltage capacity. The insulation stage in the Driver board is crucial for the full bridge topology. You might have noticed that the PSC600-series has both high input and output voltages. As we are in details, currently the PSC600-series use both Push-pull and Full-bridge depending on input voltage.
Full-bridge principle schema
In the PSC600 the planar transformers are large compared to the PSE-series therfore we could not get the same “hedge” by Full-bridge. That is the reason we stick to the Push-pull design however we improved the yield of the planar PCBs by avoiding higher input/output voltages.
The previuos PSC-series had a traditional winded transformer and we used two transformer sizes, one large for the PSC “10TE” and a smaller for “8TE”, 50 – 80 W units (for old designs still in use). This small transformer showed to perform very well if cooled, then we can easily supply up to 300 W.
That fact made Polyamp trying to case everything in the “8TE”, which we succeded. 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 also increased the efficiency. Therfore, in general we have 20-30% less losses than previous PSC-design.
The main difference between PSE and PSC-series is the flexibility in making what the customer likes within the range Box, illustrated above. Of course some models are in competition, then choose the lower price PSE-series.