Brand new car USB adapter charges your iPhone at the speed of snail? Indeed, some of the chargers even for a long trip the phone or tablet can “suck” only a few tens of percent of energy! Experts resource Kolesa tried to find out why buying a cheap charger in the cigarette lighter – lottery.
Many car owners have noticed that car chargers plug into the cigarette lighter, work in different ways. Some charge quickly, others slowly and still others not only “blunt”, but also unable to even start the charging process on shrunken to zero the phone… Why is this happening is a mystery for the average car owner…
Need urgent charging in the car, the author of these lines himself was forced to urgently buy during the trip, car USB adapter in the store, better known popularly by the nickname of “All for 37 rubles”. The price is great, only when working in the real Navigator with this adapter the phone is not charged, but only hesitantly teetered on the original battery… When I try to put on the charging device, the battery which village to extinction, USB adapter couldn’t even “budge” – the battery of the smartphone just didn’t want to go into charging mode!
Why some chargers show so little talent? And is it possible to somehow figure out TO buy or to fix something later?
On the test-the opening was visited by three car chargers with USB connectors that showed their complete or partial unfitness, charging smartphones and tablets slowly, very slowly, and even demonstrating an inability to translate a charging iPhone 6 with a fully planted battery. This charger from “All over the 37”, the charger from the store “Auchan” and another, of unknown origin. All the gadgets is absolutely “mongrel”, noname.
Typically, within each charger is the specialized mikroshemka from the category of so-called “DC/DC Step-Down converters”, plus several related passive parts, which are called “strapping”. This chip makes 12-14 volt automotive ignition 5 volts provided by the USB standard. Dismantle the chargers and thoughtfully look at their “guts”. Find chip-stabilizer – she’s alone and her with anything not confuse. Read the name written on the chip, searching for her description from the manufacturer – so-called “datasheet” and see what she’s really capable of.
For example, the charger from “All for 37 rubles”. It says that it provides an output current of 500 mA, which really is not enough for a smartphone. But on subjective sensations, even of this current is not in sight!
Reveal the body of the charger and see that it was assembled on the basis of chip MC34063. This is a good and well known to the electronics IC-switching regulator that provides output current… up to 1.5 amps! Chic current (if it is appropriate to talk about the current!), suitable for fast charging of smartphones with powerful battery, and even tablets. However, for some reason this is not happening – smartphones charged barely, by 15-20 per cent per hour…
Read the chip datasheet and see that the output current of the chip is governed by the elements of “strapping” – namely, a certain resistor. When the resistance is equal to 0,2-0,15 ohms, the chip will give a current of about 1 ampere, the resistance of 0.1 Ohm – maximum of 1.5 amps.
What was installed actually? Oops…. The Chinese are soldered in parallel 2 resistors of 1 Ohm, total of 0.5 ohms and limits the output current MC34063 level funny 300 milliamperes – almost five times less than this wonderful chip can provide!
What is a charging current of 300 mA? Well, except that the simplest push-button phone with a tiny battery, and even then not quick… But the iPhone 6s Plus with battery 2750 mAh this current categorically not enough.
Why the adapter is so assembled?
Yes, because the Chinese did not have at hand the components of that denomination, and they put the parts out of the bucket, where there was something at the bottom without bothering with accuracy and recommendations of the manufacturer of the chip.
Other defective Chinese charger DIY – exactly the same story… Take the next charging on the housing, which announced an output current of 800 mA. Open and see good old familiar – the chip MC34063. Look at the notorious par value of the resistor regulating the current – and we see the resistance of 0.33 Ohm. And its output current is, according to the manufacturer of the chip, 450 mA, not 800, as promised.
Next open the charger and see the most popular MC34063 chip, but the adjustment resistor has a value of 0.7 Ohm, which ensures the current less than 200 mA! This is a complete finish – this adapter is no good for anything…
Conclusions General and global:
– Tested all the chargers though, and limited the charge current to an abnormally low level, but still provide the required output voltage of 5 volts and somehow translated not discharged “to the plastic” phone in charging mode – for this reason, you will be extremely difficult to prove to the seller that he sold you a defective adapter.
– Alas, despite the love of many to the low cost, the spell is “why pay more” and “counterparts with Aliekspress”, in the case of a charger it’s worth noting that the lower price category is not characterized by quality and reliability, is to buy chargers with no names and cost 100 rubles cheaper is hardly worth it.
– And last, the final thesis – all tested “three-kopeck” the chargers technically COULD provide the necessary current and to charge the phones quickly, but were initially, during manufacturing, ruined illiterate Chinese Assembly.