SEGA MOON CRESTA SUPERGUN ADAPTOR
This adaptor is used to run Sega Moon Cresta PCBs, and other boards with a similar 22 pin connections that require an 8 volts AC supply.
The adaptor plugs directly into the 240v mains supply, and connects to the main Supergun only to supply RGB signals to the monitor and for the speaker connection. The adaptor has a built in Digital Voltmeter, for monitoring the regulated voltage on the main board, or can be used to monitor other DC voltages, via the yellow clip on the flying lead.
The AC transformer is fused on both windings at 3.15A with the fuse holders accessible from the front. There is a 630ma antisurge mains fuse on the rear to protect the transformer.
Here is the internals of the adaptor, you can see the mains toroid transformer on the left. At the top is a bank of six diodes with a fan close by. These are used to drop the output voltage of the toroid slightly, as the Sega boards do not like 9VAC, preferring around 7.5VAC. Three diodes are used on each winding to drop the voltage by about 1.5 volts. There is also a 5 volt regulator to supply power to the DVM.
This is the inside top of the adaptor, showing the back of the Lascar DVM module and switch connections.