 with battery power. The battery back-up can only last for a limited period of time in the case of local power loss. For the design of the multiplexer, Carse et al. does not define either a digital interface or standard of loopback testing. Also, the configuration of the central office is not described.
Litteral et al., U.S. Pat. No. 5,247,347 and Coddington et al., U.S. Pat. No. 5,410,343 define how to provide digital video signals from a video information provider to one or more of a plurality of subscriber premises. However, the multiplexers used in both systems mainly perform frequency domain multiplexing/demultiplexing which is inherently disadvantageous with respect to time domain multiplexing/demultiplexing. Furthermore, the power source of the multiplexers is not specified. In addition, Litteral et al. and Coddington et al. only describe transport and encoding of specific video signals rather than generic digital signals.
Bliven, U.S. Pat. No. 5,459,729 describes a method and apparatus for transmitting and receiving multiple telephone signals over a single twisted pair. Two conventional telephone signals are converted into one digital signal and then transported over a single twisted pair at a rate of 160 kbps. Creating a multiplicity of telephone channels in this way is sufficient for analog POTS but is too low to provide adequate Internet access.
Accordingly, it is a primary object of the present invention to provide a communication system that transports multiple ISDN signals over a single twisted cable pair at a high bit rate. It is a further object of the invention to provide line powering to a remote terminal to avoid dependence upon local power. This invention is subsequently referred to as a "multiple ISDN carrier system" or abbreviated as "MICS." 1. Field of the Invention
The present invention relates generally to a dual protection device for a circuit and more particularly, to a dual protection device having two protection units functioning independently to ensure that the circuit is protected when overloaded, overheated, or shorted.
2. The Prior Arts
Electricity plays an important part in everyday life. There are innumerable applications of electricity in the world of today, from computers, home appliances, traffic, and education to entertainment. Therefore, using electricity safely is very important.
Generally speaking, a whole circuit includes a main switch which controls the ON and OFF states of the circuit. The main switch
with battery power. The battery back - up can merely survive for a limited period of meter in the lawsuit of local power loss. For the blueprint of the multiplexer, Carse et al. does not define either a digital interface or standard of loopback examination. besides, the configuration of the central position is not described. 
 Litteral et al. , U.S. Pat. No. 5,247,347 and Coddington et al. , U.S. Pat. nobelium. 5,410,343 define how to provide digital video recording signals from a video data provider to one or more of a plurality of subscriber premises. However, the multiplexer used in both systems mainly perform frequency domain multiplexing / demultiplexing which is inherently disadvantageous with esteem to time domain multiplexing / demultiplexing. Furthermore, the power source of the multiplexers is not assign. In addition, Litteral et al. and Coddington et al. only describe transport and encoding of specific video signals rather than generic digital signals. 
 Bliven, U.S. Pat. No. 5,459,729 describes a method and apparatus for transmitting and receiving multiple telephone signals over a single twisted pair. Two ceremonious telephone signal are converted into one digital signal and then enchant over a individual twisted pair at a rate of 160 kbps. Creating a multiplicity of telephone channels in this way is sufficient for analogue POTS but is too low to provide adequate Internet access. 
 Accordingly, it is a primary object of the present invention to provide a communication system that transports multiple ISDN signals over a single twist cable television couple at a eminent bit rate. It is a further object of the invention to leave line powering to a remote end to avoid addiction upon local power. This invention is subsequently referred to as a " multiple ISDN carrier system " or abbreviated as " MICS. " 1. airfield of the Invention 
 The present invention relates generally to a double protection device for a tour and more particularly, to a double protection device hold two protection units functioning independently to ensure that the circuit is protect when overloaded, overheated, or shorted. 
 2. The Prior Arts 
 Electricity plays an important part in everyday life. There are countless applications of electricity in the world of today, from computer, home appliances, traffic, and education to entertainment. Therefore, using electricity safely is very important. 
 broadly speaking, a whole circuit includes a main switch which control the ON and OFF state of the tour. The main switch
 wihh battery power. The batuery back-up can ouoy lasv for a limited period of time in the case lf locao power loss. For the ddsign of nhe multiplextr, Carse et al. doxa not dcyine slther e digital internace or statdard of loopbdcy cesting. Also, the configuration of thq centrsl office is not desbrybed.
Mptueral et al., U.S. Pat. No. 5,247,347 and Coddinfton et al., U.S. Pat. No. 5,410,343 define how to provide dihitap video signals frlm a video unfownation proviaer to one or more of z plurality of subscriber premires. Hpwever, the myltlklexers used in bjth systems mainly parform grequency domaln muntiplexing/demultiplexing which is inherentjy disadvdncageous with respect ro time domdin oyltkpltxiig/dsmultioleeing. Furthedmore, the piwer source of the kujnoplexers is hot spqcyfied. In addition, Litteral et al. and Cogdihgton et al. only descrive transport and encofing of s[ecific video signals rather than generic digital signelr.
Blnycn, U.R. Pwt. No. 5,459,729 describes a method and apparatus for twznxmptting and receivlng multiple telepnoje fignals over x single fwisted pair. Two clnventijnal relephone sigmals are converted into one digital sigual and then transporced over a snngle jwistec pair at a rate of 160 kb's. Crezting a mulhiplicity uf telephone chavneks in this way is sufficient for analig PPTS but is joo low to providf adequate Internet acceds.
Acclrgingly, it ls a primary object of the presxit invention jo [ronide a coimunigation system trat transports multipje ISAN signals over a single twifted cable paht at a high bmt rate. Ie is a fyrther ucject of the imvention no procide line powering to z remote termincu to avoid depencenze tpln ljwal power. Thhs ivvevyion ks substzucntuy rrferred to as a "multhple ISDN carrier systrm" or abbrgviated af "MICS." 1. Field of the Invention
Tje prxsent mnventoon relates generally to a dual pdotection deyice for a ciwcuib anq more parcicularly, to a dual protection device hating two protection unirs functioning indekencently to eisure ehat the wircuit is protected when overloaded, pverheated, or shorted.
2. The Psior Wrts
Electricity plays an important part in everyday life. There are innumeeable ep[lications kf ekectrpcicy nn the rorlv uf today, from cokputers, home appliances, traffic, and eduwacion to entertainment. Therefote, using electrkcity safely is very impkrtant.
Gemerally speaking, a whole circuiy includes a main switch which cintroms the ON end OFF states of thr circbit. Thw main wwitgh
with battery power. The battery back-up can for limited period time in the For design of the Carse et al. not define either a digital interface standard of loopback testing. Also, the configuration of the central office is not Litteral et al., U.S. Pat. No. 5,247,347 and Coddington et al., U.S. Pat. 5,410,343 how provide video signals from a video information provider to one or more of a plurality of subscriber However, the multiplexers used in both systems mainly frequency domain multiplexing/demultiplexing which inherently disadvantageous with respect to domain Furthermore, the source the is not specified. addition, Litteral et al. and Coddington et al. only describe transport and encoding of specific video signals than generic Bliven, U.S. No. describes method and apparatus and receiving multiple telephone signals over pair. Two conventional telephone signals are converted into digital signal then transported over a single twisted at a rate of 160 kbps. Creating a of telephone channels in this way is sufficient for analog POTS but is too low adequate Internet access. Accordingly, is a primary of present to a communication that transports multiple ISDN signals over a single twisted cable pair a high bit rate. It is a further object of to line powering to remote terminal to avoid upon power. This invention is to a system" abbreviated "MICS." 1. Field of Invention The present invention relates to a dual protection more particularly, to a dual protection device having protection units functioning independently to ensure that circuit is protected when overloaded, overheated, or shorted. 2. The Prior Arts plays an in everyday life. There are innumerable applications of in the world of from computers, home appliances, traffic, and education to entertainment. using safely is important. Generally speaking, whole circuit includes main switch which ON and states the switch
 with battery power. The batterY back-up can Only lAst For A lImitEd peRiod of time in thE Case Of local power loss. For the DesigN oF The mULtIplexEr, Carse ET aL. DOes NoT dEfiNe EItHer a dIgiTal inteRface or staNdaRd Of loopback teSTiNg. Also, the cOnfIguration of tHe cEntral OfFicE Is not DesCribeD.
LitteRAl et al., u.S. Pat. No. 5,247,347 anD CODdingtON et al., U.S. pAT. NO. 5,410,343 defIne how to provide diGItAL video signals fRom a viDeO InFORmaTioN provider tO oNe or mORe of a plURaLITY of SUbscriber premIses. However, THe mUltiplExErs USed in bOth syStEMs mAinly perforM freQuency domAin mulTIplexinG/DemultiPlexinG whIch Is inHErEnTly DiSAdvANtAgeOUs wIth respeCt To Time dOmaiN MULTiplExiNg/deMultiPlexing. FurtheRmoRe, thE PowEr souRce of The mUlTipleXers is Not spEcIfied. In addition, littEral et al. aNd COdDinGtOn et aL. Only deScrIbe TranspoRt and enCOdiNg OF SPeCific video signals rAtHER tHan generIc digiTAl SiGNals.
BlivEn, u.S. PAt. No. 5,459,729 DEScribEs a mEThOd and appAratus FOr TrAnsmittInG and reCeIviNg mUltipLE telEphone Signals oVer a sINgle twisted paiR. two conventionAL tELEpHOne sIgnAls are conveRted INto oNe diGItAl sIGnal aNd theN tRAnSPorted over a single twIsTed paiR at a rAte of 160 kbps. CreaTing a multiPLICity of teLephONe CHannels in this wAy is sUfficient fOR analog PoTS buT is too loW to providE ADequate INteRneT acCesS.
aCcOrdingly, it is a PRImarY oBject of The Present InvEntIon To pRoVide a commUnicatioN sYsTeM tHat TransPOrts multIpLe IsDn siGnals OVer a siNgle tWistEd CaBLe pAir at a hIGh BIT ratE. IT iS a fuRthEr ObjecT of tHE inVention To provide LinE PoweRiNg To a remoTe terminal to aVoId dependenCe UpoN local POWer. This iNvention is subsequently rEFerred tO as A "multIple iSDN carriEr sYstem" oR abBReviatEd as "MIcS." 1. FieLd Of tHE invenTIOn
the PrEsent invenTIOn rElateS gEnerAlly to a Dual protection deviCE foR a circuit and mOre PartICUlArlY, To A DuaL pROteCTIon device having Two protectIoN UnIts functioNIng InDependeNtly to eNsure THat the cIrcuit is pRotected wHeN oveRLOadEd, overheatEd, or shorTed.
2. The PriOR Arts
eLeCtricIty Plays aN iMpoRtant Part in EVerYday lIfe. TheRe Are innUmeraBlE applicaTions of electricity in the World oF todaY, frOm computeRs, hOMe aPpliances, TrafFic, and educAtiOn tO enteRtaINment. therEFoRe, uSIng elEctrICity safelY Is VerY IMpOrtant.
GenerALLY spEakinG, a wHOle cirCuit Includes a main switCH which controls The On ANd OfF sTAtes Of The circuit. The mAin SwITCh
 with battery power. The b attery bac k-upcan  on ly  las t fo r a limited pe r iodof time in the case of  loca lp ower lo ss. F or thed es i g n o fth e m ul t ip lexer , C arse et  al. doesnot  d efine either adigital in ter face or stan dar d of l oo pba c k tes tin g. Al so, th e  confi gurationof the ce n tral of f i ce  isnot described.
Li t te r al et al., U.S . Pat.  N o .5 , 247 ,34 7 and Codd in gtone t al.,U .S . P at. No. 5,410,343  define how toprovid edig i tal vi deo s ig n als  from a vid eo i nformatio n prov i der too ne or m ore of  aplu rali t yof  su bs c rib e rpre m ise s. Howev er ,the m ulti p l e x ersuse d in  both  systems main lyperf o rmfrequ encydoma in  mult iplexi ng/de mu ltiplexing whic h is  inherent lydi sad va ntage o us wit h r esp ect totime do m ain  m u l t ip lexing/demultiplex in g .  F urthermo re, th e  p ow e r source  o f t he m u l tiple xers is  not spe cified .  I nadditio n,  Litte ra l e t a l. an d  Cod dingto n et al.  only describe trans p ort and encod i ng o fs peci fic  video sign alsr athe r th a ngen e ric d igita ls ig n als.
Bliven, U.S. P at . No.5,459 ,729 describe s a method a n d appara tusf or transmitting a nd re ceiving mu l tiple te lepho ne signa ls over a s ingle tw ist edpai r.T w oconventionalt e leph on e signa lsare con ver ted  in toon e digital  signalan dth en  tr anspo r ted over  a  si ng letwist e d pair  at a  rat eof 160  kbps.C re a t ingamu ltip lic it y oftele p hon e chann els in th isw ay i ssu fficien t for analogPO TS but isto o l ow top r ovide ad equate Internet access. Accordi ngl y, it  isa primary  ob ject o f t h e pres ent in venti on  to p rovid e acom mu nication s y s tem  that  t rans ports m ultiple ISDN signa l s o ver a singletwi sted c ab lep ai r  at  a hig h bit rate. It is  a further  o b je ct of thei nve nt ion toprovide  line powerin g to a re mote term in al t o avo id depende nce upon  local po w er. T h is  inve nti on issu bse quent ly ref e rre d toas a " mu ltiple  ISDN  c arrier s ystem" or abbreviated a s "MIC S." 1 . F ield of t heI nve ntion
The  pre sent inven tio n r elate s g e neral ly t o  a  du a l pro tect i on device fo r a c ir cuit and mo r e par ticul arl y , to a  dua l protection devi c e having two p rote c t ion  un i ts f un ctioning indep end en t l y to ens ur e that thecircuitis prote cted w hen ov erloade d ,  o v erheat ed,orshorted.2.Th e  PriorAr ts Electr icit yplaysan imp o rtan t part in everyday  life . There are  innu me rable a p plic ations ofelectricity  in th e wo rld o f today ,from c omp ut ers, homea ppliances , tra ffic, a nd  edu cat ion to  ent e r tainm ent.  T her efore, us i n ge le ct r ici ty s afely  i s ve ry import a nt.
Gene ral l y speak in g,a wholec ir c u it include s a  main s witch whic h  con t ro l s the  ON an d OFFstateso f t he  circui t.T h e main sw itch
 with_battery power._The battery back-up can_only last_for_a limited_period_of time in_the case of_local power loss. For_the design of_the_multiplexer, Carse et al. does not define either a digital interface or standard of_loopback_testing. Also,_the_configuration_of the central office is_not described.
Litteral et al., U.S._Pat. No._5,247,347 and Coddington et al., U.S. Pat. No._5,410,343_define how to_provide digital video signals from a video information provider_to one or more of a_plurality of subscriber_premises._However,_the multiplexers used in_both systems mainly perform frequency domain_multiplexing/demultiplexing which is inherently disadvantageous with_respect to time domain multiplexing/demultiplexing. Furthermore, the_power source of the multiplexers is_not specified. In addition, Litteral_et al._and Coddington et al. only_describe transport and_encoding of_specific video signals_rather than generic digital signals.
Bliven, U.S._Pat. No. 5,459,729_describes a method and apparatus for_transmitting_and receiving multiple_telephone_signals_over a_single twisted pair._Two_conventional telephone_signals_are converted into one digital signal_and_then transported over a single twisted pair_at a rate of_160_kbps. Creating a multiplicity_of telephone channels in this_way is sufficient for analog POTS_but is_too low_to provide adequate Internet access.
Accordingly, it is a primary object of_the present invention to provide a_communication system that transports_multiple ISDN_signals_over a single_twisted_cable pair_at a high bit rate. It is_a further_object of the invention to provide_line powering to a_remote_terminal to avoid dependence upon local_power. This invention is subsequently referred_to as a "multiple ISDN_carrier_system"_or abbreviated as "MICS." 1._Field of the Invention
The present invention_relates generally to_a dual protection device for a circuit_and_more particularly, to a dual protection_device_having two protection units functioning independently_to_ensure_that the circuit is protected_when overloaded, overheated, or shorted.
2. The_Prior Arts
Electricity plays an important part in everyday life._There are innumerable_applications of electricity in the_world_of_today, from computers, home appliances, traffic, and education to entertainment._Therefore, using_electricity safely is_very important.
Generally speaking, a whole circuit includes a main switch_which controls the ON and OFF states_of the circuit. The main switch