Car charger, pay attention!

[Guest cici]

Hi, guys,

Please be carefull if you buy non-original car adapters, they can kill your Omnia, if not immediately, at least short in time, by overheating. I bought this adapter from elcell supplied together with the windscreen mount for Omnia http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...em=200263801511. Considering the low price, one can't be very pretentious concerning the object's quality... Anyway, the biggest problem is the voltage delivered by the car adapter, that in my case was 5.99V instead of 5.05V delivered by the original main adapter. On the original main adapter is written 5.00V output, so, the voltage's tolerance is more than acceptable. What to do with the car adapter in this case? This ~1V difference will be dissipated inside Omnia during recharging, that means a lot of extra warm for nothing. First of all, you should dismount the car adapter; you'll see everything inside is flimsy, with 4 wires ready to break up and the fuse's spring turned 180 degrees. First of all, these wires must be removed, adjusted properly and then resolded and fixed using some glue, or, better, a gun with hot silicone. The same for the spring, it must be fixed inside the case in the proper position using hot silicone. Then the resistive divider must be recalibrated, it's a classical scheme using the 34063 DC-DC converter http://www.china-zitaijing.com/down/ic/34063.pdf. In figure 11 is a divider R1 and R2 that dictates the output voltage; in this car adapter's case, R1=1.5K and R2 is 5.6K. For example, higher R2 value means higher output voltage. Now, there are two alternatives: replace R2 with another 4.5K resistor, or put in parallel with the existing 5.6K resistor another one of 22K! I choose the second because 22K is a common value, while 4.5K is hard to find, and inside is plenty of room, and finally I've got 5.04V output, that is the right value for Omnia! Good luck and be careful, a 3 euro device can easily destroy a 500 one!!!

Edited November 14, 2008 by cici

[Guest adzrm]

thanks for sharing!!

[Guest zagzag99]

thanks for sharing!!

Will opening the Monitor on the Omnia (*#0228#) while plugged to the car charger be a good way to read the voltage produced by the charger ?

[Guest cici]

Will opening the Monitor on the Omnia (*#0228#) while plugged to the car charger be a good way to read the voltage produced by the charger ?

Yes, it's a good idea once you have a trustful adapter, but what to do if the voltage is already too high, or if the polarity is accidentely reversed by the manufacturer mistake, sometimes it can happen! I mean, it's better (in my opinion) to fix everything before Omnia's first connexion to the car charger, and this is true for all kind of expensive electronics. I always considered dubious this kind of cheap no name adaptors/chargers, and always I make a visual, mechanical and electrical check out before starting to use it and trust it. In my experience almost everytime I had to fix something that wasn't done by the manufacturer in a proper way, avoiding later expensive troubles.

[Guest zagzag99]

Yes, it's a good idea once you have a trustful adapter, but what to do if the voltage is already too high, or if the polarity is accidentely reversed by the manufacturer mistake, sometimes it can happen! I mean, it's better (in my opinion) to fix everything before Omnia's first connexion to the car charger, and this is true for all kind of expensive electronics. I always considered dubious this kind of cheap no name adaptors/chargers, and always I make a visual, mechanical and electrical check out before starting to use it and trust it. In my experience almost everytime I had to fix something that wasn't done by the manufacturer in a proper way, avoiding later expensive troubles.

Unfortunately i don't have enough knowledge and equipment to test it.

I do have a car charger... without a name. I already tried it before, it works... charges the phone can't judge it otherwise

[Guest gravityz]

i think i bought almost the same thing

mine however came with a screenprotector and a charger which says SAMSUNG.

it does not look like the charger on the photo you posted

i will measure the voltage to make sure

thanks

Unfortunately i don't have enough knowledge and equipment to test it.

I do have a car charger... without a name. I already tried it before, it works... charges the phone can't judge it otherwise