susanpmtbc, it's too bad you hadn't found these Boards earlier, but I'll try and offer some suggestions to help with the voltage converter.
First of all, you need to check the power supply "cube" or whatever powers your Laptop, to determine the input voltage.
It's a good idea to check this on ALL electrical devices that you will be taking with you! The spec's should be listed on a nameplate, usually on the bottom of the power supply. The lettering is usually quite small (ie: difficult to read), but if the input voltage is listed as "115 VAC, 60 Hz", you WILL need to use a voltage converter (step down converter) to use your Laptop with the U.K. electrical system.
On the other hand, if the input voltage is shown as "100-240 VAC, 50/60 HZ", this will work on the U.K. electrical system on it's own. You WILL however need a
Plug Adapter, which in the U.K. uses
three large rectangular pins. The Laptop Plug will likely only have two pins, so the earth / ground pin won't be used. I find it's a good idea to travel with two or three Plug Adapters for each region. BTW, DON'T forget these when you leave each lodging!!!
Next, the Hair Dryer. It was mentioned in your OP, so I'm assuming that you plan on travelling with one??? If this is the case, you might be better to buy a cheap Hair Dryer when you land (might even be available in the airport?), as Dustoffmom suggested. Some "travel" (dual voltage) Hair Dryers seem to have a quirk in that they operate really well on one voltage setting, but not so well on the other.
If you decide to take your present Hair Dryer with you and it ONLY operates on 115 VAC, then you will need a voltage converter. For Hair Dryers and other "brute force & ignorance" electrical devices which are basically just a resistive load, a
solid-state voltage converter is likely the only solution as a Transformer-type converter would be too large and too heavy for this wattage. However, if the Dryer uses electronic controls or other "high tech" stuff, the situation beomes more complicated (not likely though).
On the other hand, if you do require a Voltage Converter for electronic devices (Digital Camera Chargers, Cell Phones, etc.) then a
transformer-type voltage converter is the best option, as the solid-state models can cause strange things to occur with devices of this type. They really need to have a stable sine wave to operate properly, something that is not necessarily provided in the solid-state models. There are "dual technology" voltage converters available, such as
www.magellans.com/store/Phone___Electric_Connectivity___Voltage_ConvertersEA238?Args=. I use one of those myself, and so far it's worked well. It's compact, reasonably light and easy to travel with.
One point to mention regarding Voltage Converters. Most of these are not designed for "continuous duty" operation,
so it's a good idea to unplug these when charging / use is finished.Regarding the voltage converter that you had "put away somewhere that has two round pins", I have two comments:
- it's extremely important to determine whether this is a solid-state or transformer type device and it's capacity, in order to determine if it will be suitable for your purposes.
- the two round pins are for mainland Europe, but should work with the Plug Adapters that you have (depending on their design). The Plug Adapters that I'm using will accept either the North American style plugs or the Euro style. They're quite verstatile. Actually, most of the voltage converters on the market seem to be supplied with the Euro pins, but Plug Adapters will be needed to use these in the U.K.
I often order products of this type from Magellans. I believe that is one of the suppliers affiliated with this web site, so if you purchase using the link it helps to support this site. Magellan's is located in the Santa Barbara area, I believe. Although "time is short" you might be able to give them a call on their toll free number, and have whatever you need sent by overnight FedEx. I had to do that with an article of Tilley clothing that I needed for my last trip. It costs a bit more, but what the heck "you're on holidays".
One point to clarify, the
second Radio Shack link in Dustoffmom's post refers to an
Isolation Transformer, which is not the same as a step-down Transformer. Usually with an Isolation Transformer, the input and output voltages will be the same. Also, as mentioned, these are large and heavy and trust me, you don't want to be travelling with one!!!
Also, as Dustoffmom mentioned, be sure that the power supplies on your electrical devices don't have a small switch to select the voltage. Again as mentioned, this was common in older devices, but most current electrical devices have "auto sensing".
Hope this has helped. Good luck and happy travels in the U.K.!!!
) They look something like this: