- This topic has 28 replies, 1 voice, and was last updated 2 weeks, 2 days ago by Olegabaft.
2nd January 2011 at 07:49 #41123vasanthGuest
why we are using -48v…
3.earthing(lightening effects)19th January 2011 at 10:35 #41124LalitGuest
Basically many reasons bt first is that noise and intrefrence is min at -ve supply voltage and second is that to protect from lightning8th February 2011 at 11:16 #41125MRGGuest
(i) Positive voltages cause comparatively more corrosion in metal than negative voltages.
(ii) Negative voltages are safer for human body while doing Telecom activities.
(iii) Lightning may cause positive voltages in the equipment circuitry. In that case, negative voltages (lack of electrons) neutralize positive charges and prevent excessive heat.
(iv) Negative voltage is safer for long telephone line for transmitting power trough it.1st February 2012 at 05:40 #41126Abid Hussain KhanGuest
Thanks to all for clear my confusion about why telecom equipment use -ev voltage but my question is why it is 48vDC (2*24), why not 50vDC (2*25)??
is there any restriction for DC voltage supply?3rd August 2014 at 15:22 #41127BIBHUTI BEHERAGuest
1* In negative voltage due direct current less noise occurs… As a result telecom equipment gives high output..
2* corrosion less on eqiupment
3* It protect the equipmet fom lightning.5th August 2014 at 16:02 #41128gyanGuest
It is -48 V D.C cause of the commercial battery stack available. Commercial battery stack is available in -12 V, -24 V or – 48 V. For info, actually any telecom equipment or for that matter any sophosticated equipment runs on a range of supply voltages by using their own inbuilt SMPS and it is very difficult to maintain a constant voltage by the power source.18th October 2014 at 07:22 #41129Vasuki soniGuest
Can negative voltages be used in other domains like power systems preferably to protect equipments from lightning and noise as has been identified in above comments..28th November 2014 at 12:57 #41130manzer aquilGuest
why use -48 volt why not -50volt in BTS9th January 2015 at 06:56 #41131sriGuest
the standard lead acid cells or others are of 12vdc. Mulitiples of 12 gives 48V.15th January 2015 at 09:47 #41132swati kumariGuest
Why dc is given to bts ,why not ac?8th February 2015 at 07:30 #41133jamesGuest
what does pulse and lightening to do with -48v DC?21st February 2015 at 08:24 #41134Tadele HaileGuest
Thank you for your informative answer to my burning question that i heard from interview question.
i hope we will be in touch.27th February 2015 at 14:07 #41135RamasabarinathanGuest
why in BTS eqiupment use only DC voltage?
can you please give informations in briefly.9th December 2015 at 08:29 #41136AmirGuest
why we use telecom equipment DC Voltage?