12 V 1000MA CHARGER W/CIG LIGHTER SOCKET Compact, portable 120 Vac power supply allows cell phones, PDAs, MP3 players and other portable electronics with a car charger to be used anywhere AC power is available. Perfect for home, office or... Sold by Rosemont Sales LLC and Fulfilled by Amazon. 100V-240V AC Input 12V 5A DC Output Power Adapter for CCTV IP Camera Provide steady power to CCTV surveillance camera, IP Camera, PC router, PC switch/hub, etc. 5.4 x 4 x 1.5 inches 2.0 out of 5 stars #4,001 in Computers & Accessories > Tablet Accessories > Chargers & Adapters SUPERNIGHT(TM) 100V - 240V To DC 12V 5A Switching Power Supply Adapter For LED strip Light TNTE 12 Volt Power Supply - 5 Amp Standard (12V 5A DC) Adapter BINZET New 100V -240V to DC12V 5A 60W Switching Power Supply Adapter for LED Strip Light See and discover other items: tablet docking stationAC Input, Dual Output Power Supply Reference Design View the Important Notice for TI Designs covering authorized use, intellectual property matters and disclaimers.

26 Aug 2015  119 views View All Technical Documents (4) The PMP4405 reference design uses the UCC28740  Flyback controller with valley-switching controller to generate dual DC output 5V/2A and 26V/0.3A from a universal AC input. The design is suited for auxiliary power for industrial applications and appliances. The design is fully tested and compliant with EMI regulationsac unit for rvs Two isolated rails delivering 18W powerair handling unit foundation Valley switching for high efficiencyac units in houston Output OVP,OCP and SCP protoction Single layer board for low cost SSR control with good cross-regulation TI's Standard Terms and Conditions for Evaluation Modules apply. PMP4405.1(Output Voltage 1)PMP4405.2(Output Voltage 2) Vin (Min) (V)8585 Vin (Max) (V)265265 Vout (Nom) (V)526 Iout (Max) (A)2.3 Output Power (W)107.8 Isolated/Non-IsolatedIsoladteIsolated Input TypeACAC TopologyFlyback- Quasi ResonantFlyback- Quasi Resonant

Order samples, get tools and find more information on the TI products in this reference design. Design Kits & Evaluation Modules Adjustable Precision Shunt Regulator Constant-Voltage, Constant-Current Flyback Controller Using Opto-Coupler Feedback Offline and Isolated DC/DC Controllers and Converters View Design Kits & Evaluation Modules As a member ofmy.TI you can join theTI E2E™ Community where you can ask questions, share ideas and collaborate with fellow engineers and TI experts Contents are provided "AS IS" by the respective TI and Community contributors and do not constitute TI specifications. Engage in the Community Broadband RF/IF & Digital Radio Visit the TI Wiki When I look at, let's say an iPad AC adapter, the input/output rating on the charger states: Input: 100-240V 0.45A (AC) Output: 5.1V 2.1A (DC) I know that the input and output ratings are maximum. The AC voltage in my country is 230V. Through a simple calculation, I can deduce the following (correct me if I am wrong):

Now, my question is this: what is the true power drawn from the wall socket? Is it 103.5W or 10.71W? If it is 103.5W, then I presume the iPad adapter is 10% efficient? Undoubtedly the charger you have is a switching regulator. I say this because that is what all modern chargers appear to be and the input voltage range is wide enough to make this assumption valid. It's not a big charger - roughly 10 watt output means it is small in my book and more than likely it will be based around the following: - Raw AC voltage is rectified to DC (peak will be about 338V DC on 240 Vac input and about 140V DC on a 100 Vac input) This gets smoothed by a capacitor - probably in region of 220 uF (rated at 450V) A switching circuit will convert this high dc voltage to 5.1 Vdc As a thought experiment, if you connected the AC input of the charger to a 140V DC supply and the charger's output to a load resistor that took 2.1 Adc (10.71 watt load) and assumed the power conversion efficiency in the charger was 80%, you would expect to see about 14 watts taken from the input DC supply of 140V.

This means a current of about 100mA. Input power = 140 Vdc x 0.1 Adc = 14 watt Output power = 5.1 Vdc x 2.1 Adc = 10.7 watt So, when you connect it to an AC supply of 100V AC RMS, why could a current of 0.45 A flow? To understand this you have to recognize that this device's AC input current (as measured through an RMS measuring ammeter) is not representative of real power into the device. Unlike DC circuits (where it would be representative of real power), AC circuits like this can draw very non-linear (non sinusoidal) currents whose RMS value could be quite high compared to the "useful" current. This means you can't make the assumption that input power into the device is Vac x Iac. The device has (more than likely) a bridge rectifier and smoothing capacitor and the current drawn will almost be like a spike of a few milliseconds every 10ms (50Hz supply). This, without doing the maths could mean that the input RMS current is twice the "useful" current: - This would take your "useful" and needed input current of 100 mA to 200 mA - a bit closer to the 450 mA stated.

Also to consider is the inrush current - the manufacturer's rating of 0.45A may include some measure of inrush current into this figure but we don't really know. Remember also that the rating will be most valid when the input AC voltage is at 100 VAC and not when the voltage is much higher (as per your calculation). As others have explained, the input and output current and voltage markings on the supply have little or nothing to do with the efficiency. If you want to know the efficiency, however, there is typically a marking that is relevant. If you look carefully at the iPad adapter, you should see a Roman numeral (mine is beside the CE marking, and is a 'V' or equivalent 5 in Arabic numerals). That is a code for the Energy Star Version 2.0 Level 5 efficiency rating. (photo modified from Apple web page) As a 10W (rating on the label) supply, it has a guaranteed minimum efficiency of \$0.0626 \cdot ln(10) +0.662\$ or 80.6%, where ln(10) is the natural logarithm of the label rating in watts.