Running 110V PDP-11 in a 220V world

On 07/10/2011 12:52, Tobias Russell wrote: It's safe, but not very efficient, and there a few other considerations. First, you need to realise that a lot of those big yellow site transformers are not rated for continuous use at the load they claim. They're intended to run power tools which by their nature are used intermittently. I don't know about that particular one, but most need derated by 50%-75% for continuous operation. Secondly, they produce 55-0-55VAC, ie centre-tapped to ground. Probably not an issue, but you should be aware of it. Lastly, although transformers can be very efficient, no transformer is 100% efficient (80%-90% is more typical). The 11/35 (ditto the 11/40, like mine) uses an H742 supply to drive the power bricks. It has a terminal strip inside that you can easily jumper for either 110V or 230V, so there's no reason not to just change it. Well, no reason except the damned thing is VERY heavy and therfoe awkward to handle, but you already know that :-) -- Pete Peter Turnbull Network Manager University of York