Recently, I actually purchased a ‘power saver’, called “Electricity Saving Box”. I didn’t buy it to save power, but to run some tests and verify that it does not save power at all.
In fact (and as expected), it uses power. Not much (less than 0.5W), and the power it uses is for one task only – to light a pair of green LEDs that supposedly “indicate that it is saving power”.
The above is a photo of the ‘power saver’, and unfortunately it’s just a complete waste of perfectly good plastic and electronic parts. The photo below shows what’s inside. There’s not very much, and what’s there doesn’t do anything useful.
The large black object on the left is a capacitor, and these are the ‘heart’ of all ‘power saver’ scams. In this case, the capacitor is 5.1μF and while it can (partially) correct the power factor of small motors (and thus reduce the current), it doesn’t reduce the power, and this is what householders pay for. This is how these scams work.
By showing the consumer that the current drawn by a motor is reduced, it is stated that this affects the power as well. No, it doesn’t. Power is the measurement of physical work being performed, and most motors draw more current than they need because that’s the way they work with light loads. Rather than repeat the whole article here, I suggest that anyone interested should read the full article on ‘power savers’ at The Great ‘Power Saver’ Fraud. Also see the test results at Test Results – ‘Power Saver’ Fraud.
NOTE: The unit I purchased was very cheap, but some are considerably more expensive. Despite the extra cost, you still get the same completely worthless box that won’t save you a cent. Yes, you can find countless ‘testimonials’ from alleged customers, but I fully expect the vast majority to have been made up by the fraudsters who sell these worthless devices.