I really don't see how these control signals in any reasonable system could cause additional risk Andy. The usual stated reason for type B RCDs is that they detect DC current as faults, rather than preventing AC fault detection by saturating the transformer. That was the reason for my post above, because it suggests that any equipment using a SMPS should have a type B RCD, which is of course foolish, or possibly necessary to comply with the latest regulations.


I note that Graham K pointed out that changing the design of electric car chargers in the future to class 2 is essentially impossible. Why? I see very little difficulty with most SMPS designs to make them class 2, with the possible exception of EMC, which is somewhat more difficult. All we need is an edict that all cars must be class 2 from next year, and no manufacturer will have any great difficulty complying if they wish to sell any cars. After all these are expensive high tech products with massive development teams available, so adding a bit of insulation cannot be that difficult. In all designs the battery is completely isolated from the mains supply, so the basic separation of systems is already present. Thus the risk becomes very small and car charging very straightforward wherever one plugs in.

I really don't see how these control signals in any reasonable system could cause additional risk Andy. The usual stated reason for type B RCDs is that they detect DC current as faults, rather than preventing AC fault detection by saturating the transformer. That was the reason for my post above, because it suggests that any equipment using a SMPS should have a type B RCD, which is of course foolish, or possibly necessary to comply with the latest regulations.


I note that Graham K pointed out that changing the design of electric car chargers in the future to class 2 is essentially impossible. Why? I see very little difficulty with most SMPS designs to make them class 2, with the possible exception of EMC, which is somewhat more difficult. All we need is an edict that all cars must be class 2 from next year, and no manufacturer will have any great difficulty complying if they wish to sell any cars. After all these are expensive high tech products with massive development teams available, so adding a bit of insulation cannot be that difficult. In all designs the battery is completely isolated from the mains supply, so the basic separation of systems is already present. Thus the risk becomes very small and car charging very straightforward wherever one plugs in.