# Mobile charging during low main supply [closed]

Due to some electrical issues in my locality, the supply voltage of 230V was unfortunately reduced to 110V. When I connected the 5V charger (Input: 100-240V AC; 50/60Hz; 0.2A & Output: 5V 800mA) to my mobile phone, it indicating charging.

How will my phone charge during 110V and what about its charging output voltage and current at this low supply voltage(110V) situation?

Can the charger pull its required 800mA for charging at this situation?

Phone chargers use switched-mode power-supply (SMPS) technology.

Figure 1. The block diagram of an SMPS. Source: Wikimedia Commons.

The chopper controller adjusts the chopper pulse widths to maintain the specified output voltage. The unit should work correctly across the specified range of input voltages.

Can the charger to pull its required 800mA fod (sic) charging at this situation..?

No, the charger will supply 800 mA.

The charger will draw about $800 \times \frac {V_{OUT}}{V_{IN}} \ \text {mA}$ from the mains. So at 100 V this will be about 40 mA and at 200 V about 20 mA. Divide each of those by the efficiency to get a more accurate number.

Note, in standard English there are no punctuation marks or spaces before a question mark. Adding them in makes your post more difficult to read.

• According to the above calculation, when the input voltage is 10 VAC, it can draw 400mA from mains. Now, can I say that there will be some heating occur due to pulling a current greater than the spec current? Thank you! – Beginner Aug 26 '18 at 15:19
• No, you cannot. The power supply will not work at 10 V AC. The specifications you quoted says 100 - 240 V AC. – Transistor Aug 26 '18 at 15:21
• Sorry.! You're correct – Beginner Aug 26 '18 at 15:23