Severall questions

Its not likely that the pump will run backwards. You will lose the grounded tip with your 'isolation' transformer.

First, it's 120V (or 117, or 110, depending on who you ask). 130 is a bit much.

Second, it's AC -- the pump will run the correct direction; it certainly can't "tell" what direction the AC is coming from.

Third, wire in a ground. Equipment designed for North American service uses a grounded frame as a safety measure; if you don't wire the frame to ground and there's a fault you may get AC on the frame of the machine. That can make for an unpleasantly exciting day.

The technical term is "big surprise."

Dan, U.S. Air Force, retired

Thank you for comments. I was wondering if I could wire that third - ground - from the 220 side... So the hot wires would be from the isolation transformer but the ground from the 220 socket. Stupid idea?

Best Regards Kari

Going from memory here, but I think that depends on which country one is in. I think the UK ground goes back to the power station, not a local ground. I'm not sure if there would be a difference if you did that. I know it's not much help, but that's as far as my thinking goes.

Dan, U.S. Air Force, retired

It won't run in the wrong direction, but it might run at the wrong speed (US mains is 60Hz, Europe is 50Hz).

It depends upon the processor and the FPGA. An ancient 8-bit CPU implemented on an FPGA might run a lot faster than the original CPU.

The main reason is that an FPGA is likely to be vastly more expensive than an ASIC which implements the same functionality. Also, I don't think that they make FPGAs which are capable of fully implementing a modern CPU (particularly an x86). A RISC CPU core might be doable, but the FPGA would have to provide the cache (you certainly aren't going to be able to build a sizeable L1 cache out of logic blocks).

Higher cost, higher power consumption, limited complexity, possibly slower.

The Playstation 3 uses the Cell, but they have dropped the ability to run Linux, and recent firmware upgrades disable it. You *might* be able to find a second-hand one which hasn't had the Linux support disabled.

That's technically correct, and is essentially what is done for grounding in North America (the pole transformer isolates the AC from any ground reference, and the building wiring goes back to a ground stake). As Dan pointed out there may be some issues with your local electrical code, though.

FPGA soft-core processors tend to be slow, because they're not designed to be processors. A microblaze cpu in a $20 Xilinx FPGA is probably 10x slower than a $9 ARM. The fpga will also usually have much less ram and cache available, which hurts for all but very small programs. An FPGA is a very expensive way to make a microprocessor.

The FPGA can win if some of the computation, like filtering or array processing or some such, can be done off to the side in many parallel blocks.

If you want serious number crunching, use a gaming-type video card. Some have hundreds of processors. Some people even sell them without the video generators, for pure computation.

John

The UK uses TN-C-S, where earth (ground) connects to neutral and to a ground pole at the entry to each building, then a separate earth wire is split off before any RCD.

On HV transmission lines, the neutral line is attached directly (without insulation) to the pylon, tying it to ground.

Thanks John and others!

Best Regards Kari

Yes, you're in the wrong business.

Help!

I see a prepositional sale of a Golden Bridge here.

You certainly are.

You would have never bought it if you had any brains.