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I did say at start GU10 is better route sorry the Philips don't work and thanks for reporting that it is something we can now tell others when they ask the same question.
As to what is an electronic transformer let me try to explain just for your interest.
It does have a transformer however it is far smaller than the normal transformer as it uses a much higher frequency the electronics allow this.
In basic terms it turns AC to DC and stores it in a capacitor then turns that DC into high frequency AC and feeds that to the transformer.
At the high voltage end it is not a sine wave but a square wave and by altering the ratio of high and low it can correct the output voltage this is called the mark/space ratio. Maximum will be 50/50 but also it does need some time to switch so minimum will vary with frequency but likely 10/90 ratio it can never be 0/100 clearly in must switch on even if for very small time. This means the output has both a minimum and maximum often shown at 10 - 50W since bulbs will blow it has to have a fail save mode so with no load it switches off.
I hope you can see there is a transformer there so calling it an electronic transformer is not really wrong we tend to call items with a DC output power supplies and AC output transformers and so it is following a convention. With DC into and AC output we call them inverters and where it controls current rather than volts on the output we call them drivers.
All domestic LED's in a bulb format seem to require a constant voltage but there are a mixture of those requiring DC only and those which can work AC or DC at the moment there seems to be a host of names for the power supply used for these and as a result it is very easy to select the wrong one.
In theory a driver will only supply one LED as it has to control current and if it supplied over one LED then if one was to fail it would supply the remaining with too much current and so cause the rest to fail. Most 50mm MR16 bulbs have 3 or more LED's so they would not use a true driver external to the bulb. However in practice it would seem the 12VDC power supply is often given the label "Driver" which is far more of a problem than calling a AC power supply a transformer.
Of course if the LED's were wired in series in the bulb you could use a driver but the result would be the same if one LED blows then all stop working.
I looked at the spec for MR16 bulbs and most are rated 12 volt with no +/- for over or under voltage although we know most will work 9 to 16 volt it does not say they will. The spec for GU10 bulbs however does give the voltage typical 190 - 250 volt so with the GU10 you know it is the correct one there is no uncertainty. I believe in KISS kept it simple silly and GU10 are simple just can't see the point in 12 volt any more except for caravans, cars, boats and other special locations.
As to what is an electronic transformer let me try to explain just for your interest.
It does have a transformer however it is far smaller than the normal transformer as it uses a much higher frequency the electronics allow this.
In basic terms it turns AC to DC and stores it in a capacitor then turns that DC into high frequency AC and feeds that to the transformer.
At the high voltage end it is not a sine wave but a square wave and by altering the ratio of high and low it can correct the output voltage this is called the mark/space ratio. Maximum will be 50/50 but also it does need some time to switch so minimum will vary with frequency but likely 10/90 ratio it can never be 0/100 clearly in must switch on even if for very small time. This means the output has both a minimum and maximum often shown at 10 - 50W since bulbs will blow it has to have a fail save mode so with no load it switches off.
I hope you can see there is a transformer there so calling it an electronic transformer is not really wrong we tend to call items with a DC output power supplies and AC output transformers and so it is following a convention. With DC into and AC output we call them inverters and where it controls current rather than volts on the output we call them drivers.
All domestic LED's in a bulb format seem to require a constant voltage but there are a mixture of those requiring DC only and those which can work AC or DC at the moment there seems to be a host of names for the power supply used for these and as a result it is very easy to select the wrong one.
In theory a driver will only supply one LED as it has to control current and if it supplied over one LED then if one was to fail it would supply the remaining with too much current and so cause the rest to fail. Most 50mm MR16 bulbs have 3 or more LED's so they would not use a true driver external to the bulb. However in practice it would seem the 12VDC power supply is often given the label "Driver" which is far more of a problem than calling a AC power supply a transformer.
Of course if the LED's were wired in series in the bulb you could use a driver but the result would be the same if one LED blows then all stop working.
I looked at the spec for MR16 bulbs and most are rated 12 volt with no +/- for over or under voltage although we know most will work 9 to 16 volt it does not say they will. The spec for GU10 bulbs however does give the voltage typical 190 - 250 volt so with the GU10 you know it is the correct one there is no uncertainty. I believe in KISS kept it simple silly and GU10 are simple just can't see the point in 12 volt any more except for caravans, cars, boats and other special locations.
