Building a power supply for an Exposure VII pre-amp
As the case leaves plenty of room for all the components, I thought I'd experiment with circuit board isolation for the regulator boards.
Naim now do this in many of their pre-amps (although I don't think they do this for their pre-amp power supplies).
The four regulator boards are bolted to an aluminium plate:
The four regulator boards are bolted to an aluminium plate:
This is then afixed to an aluminium leaf-spring which runs down the centre of the case, between the two transformers. The spring 'pivots' on a piece of polypropylene, the end of the spring being fixed down to the chassis via a bolt (some form of grommet isolation still to be determined):
The leaf-spring is simply a piece of aluminium strip 10mm x 2mm from B&Q and with the weight of the boards/plate oscillates at what looks like 2-3 Hz. Without the damping effect of any wiring, oscillation time is rather long as can be seen in this movie clip [Wmv file, 8.3Mb]