Why do shaver sockets accommodate round pin plugs in the 115V outlet when countries with 100V to 120V mains supplies use type A plugs with flat pins? Is there a country somewhere with a 100V to 120V mains supply that just so happens to use shavers with round pin plugs?
In North America where both HV and LV on the same pole seems to be the norm, the usual practice appears to be to use three separate single-phase transformers, each with a single HV bush connected to a phase. The three transformer tanks are connected together and to an earth electrode. At least in this case with there being a 3-phase supply, the overall earth current will only be the out of balance HV neutral current. In Pusan, South Korea, another user of Single Wire Earth Return, it was normal to see Variacs (variable transformers) in bars and cafes so that as the transformer load increased and the LV dropped, the Variac could be adjusted to increase the voltage so as to keep the lights at their required brilliance.
Be careful with UK bathroom outlets. The transformers in them have poor regulation. On no or low load (such as a charger) the output voltages are around 140v on the 115v side and 280v on the 240v side. My toothbrush charger is rated at 100-250v and I always plug it into the 115v side as I consider 280v an overload.
An old shaver socket from the 1970s. The 230V outlet has holes for both BS4573 and type C plugs. The 110V outlet has holes for both type A flat pin and (type C?) round pin plugs.
Did any countries in Europe have 100V to 120V mains supplies with sockets that accommodated a type C plug back in the 1970s?
ISTR seeing a 3-wire 220v supply where the voltage across phases was 220v and any phase to neutral 127v in Majorca in the 1980s. Not sure of what our hotel had. Certainly in 1973 we took a dual-voltage hairdryer to Tenerife for our honeymoon, but whether the type C sockets were 220 or 110/127 I cannot remember.
Both Paris and Luxembourg were on 127v in the late 60s. Not sure when they changed to 220v.
That might answer the question as they definitely used type C plugs with two round pins.
I was once verbally informed that some 'downmarket' suburbs of Paris had (the option of?) lower voltage AC mains supplies well into the 1980s. I have no knowledge of whether many appliances were commercially available that ran on 127V or if they tended to be used just for light bulbs unless a step-up transformer was used.
That's interesting about Luxembourge having 127 volts in the 1983 edition of the WRTH it's listed as 110/190 volts I wonder were they got that from? Also some parts of Vienna were on 127/220 at that time too
It raises the question, after factoring out Brazil, whether the facility for the 115V outlet to accommodate a type C plug with round pins in modern day shaver sockets verges on an anachronism from the time when Europe had 110V or 127V mains supplies? The number of shavers from that time with a type C plug that requires the 115V outlet still in use today must be miniscule.
It's possible that the situation in Brazil where a type C plug fits a type N socket on a 127V mains supply is a coincidence rather than a compelling reason for the manufacturers of shaver sockets to continue to offer the facility for the 115V outlet to accommodate a type C plug, and the manufacturers might not even be aware of it.
I would not buy one that could not take type C plugs in the 115v socket for reasons about the poor regulation I mentioned earlier.In fact I don't buy MK ones either as although they can take type C plugs in the 115v side they cannot tale UK shaver plugs there.
