Small Converter Efficiencies

The 100-240 "rating" simply means that is the acceptable minimum/maximum supply voltage.

If the manufacturer doesn't provide a stated efficiency, then you'll need to calculate the efficiency by comparing the measured input versus the measured output.

(Even if they give an efficiency rating, it's going to vary somewhat with the specific end-user implementation.)

The figures simply show acceptable voltage range on the input, typical voltage on the output and typical maximum current.

The efficiency of the equipment connot be determined accurately from these figures without measurement of the actual values with the equipment in service. In the absence of a meter, the measurement cannot happen and therefore any guesstimate will involve a large range of possible error.

Apart from the academic interest, the need to know the efficiency of such a small device is somewhat abstruse.

As the others have said, nothing you posted is relevant to efficiency, those are maximums and ranges.

As a gross generalization however, we can assume that is a Switch Mode Power Supply (SMPS) because of the wide input voltage range. So all it does is rectify the AC to DC, then use a DC chopper circuit and a filter to provide a consistent and regulated low voltage DC output. In general, SMPS have an efficiency of 75-95%, depending on design. If that one was cheap, it will be in the lower end of that range as the way to improve efficiency is to use better materials and designs.

The input current rating may be the switch on inrush current or maximum surge current, rather than the steady state or average input current.

On the other hand you may be correct, the power supply may be very inefficient - it will be built to a price to maximise the manufacturer's profit, not to minimise your power consumption.......

To be sure you would need to measure the input current and RMS voltage and output current and voltage, then calculate the input and output power.

To optimise the efficiency you would need to design your own power supply, but it will cost a little more to do.

The rated input is variable, it doesn't matter what the exact voltage is, provided it's greater than 100 and less than 240, the power supply will adjust to supply a constant 6 VDC output for a Max. lode of 1.6 Amps. A 1 Amp. lode would be a perfect match for your power supply; the Amp's required will be limited by the resistance of the LED lights, and input curent will be reduced in responce to the lode. Unless you plan to instal thousands of these power supplies/LED combanations your energy consuption should be a problem.

Sorry: should not be a problem

As an after thought; your switching configuration (lights on or off) should be controlling the power supply, and not the LED indapendinly. The power supply will consume electricty with or without a lode.

The power supply will consume electricty with or without a lode.
But if it is switch mode, which it probably is, scarcely any.

Just as a WAG, You are dissipating 9.6 watts of output power. If the supply is 75% efficient, you should have 12.8 watts of input power. If your line voltage is 100 volts, your input current would be .128 amps.

Or to look at it another way, IF your input current is .4 amps at 100 volts, you would have 40 watts of input power and your efficiency would be 24%.

Bill

Thanks for all the input.

I am going to go with a conservative figure of 50% efficiency for the converter. This still leaves a lot of room for energy savings using the simple low voltage LED's I am promoting here in the south pacific.

These poor people pay over 62 dollars (US) a year to light a 35 watt bulb 8 hrs a day.

The ones without electricity are using batteries to light LED lamps then dumping the old batteries into the trash. I have even see gas powered generators being used to charge cell phones.

A 20 watt solar battery charger and a car battery could bring basic lighting to two homes using the self assembled system I am promoting.

Dear Engineers; want to make a mint in paradise and give some poor people a break? Come on in - the waters fine!

Gavilan