Explain the configuration of a step-by-step switching system, Electrical Engineering

Assignment Help:

With neat diagrams explain the configuration of a step-by-step switching system.

Schematic diagram for such an exchange is given in Figure.  Every subscriber is connected to a single rotary pre-selector switch at the exchange, outputs from this switch being connected to a bank of two-motion switches called "group selectors". The  out-puts  from  pre-selector  switches  of  a  whole  group  of subscribers are connected together in parallel as that group of subscribers share a single bank of group selectors. When a subscriber lifts his telephone, cradle switch causes a circuit to be completed back to telephone exchange, signalling that subscriber wishes to make a call. This causes pre-selector switch to step around until it finds a free group selector. Pre-selector switch then stop in this position and group selector is 'seized' by subscriber wishing to make a call.

1747_micro.png

On  seizing  group  selector,  the  subscriber  dials his  first  digit  and  selector switch  moves  up  to  the  appropriate  row  on  switch  contact  array.  Every final selector has the possibility of connection to 100 lines. 1000 lines are thus divided into 10 groups of 100 each, group being identified by the first digit in the subscriber's number. Vertical motion of the group selector hence selects a final selector in the group associated with first digit dialled. Every individual row  of  contacts,  or  levels,  of  group  selector  is  connected  to  a  bank  of  final selectors associated with a specific group of 100line numbers. Having dialled first digit to select appropriate group, group selector arm then automatically rotates  in  vertical  direction  until  it  finds  a  free  final  selector.  In  final selector, both directions of motion are under the control of subscriber's dial and after  dealing  two  further  digits,  connection  is  established,  providing  called subscriber's to answer his telephone.

 

 

 


Related Discussions:- Explain the configuration of a step-by-step switching system

Second Order Precesses, A second-order process with one pole at the origin ...

A second-order process with one pole at the origin has the transfer function 3/(s(2s + 1)) Find the output as a function of time, for a unit step input change. Sketch the expected

The parallel resistance rule, The Parallel Resistance rule ...

The Parallel Resistance rule Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Compute the current loss in the lines, Q. Consider a 240-V supply feeding a...

Q. Consider a 240-V supply feeding a resistive load of 10 kW through wires having a total resistance of R = 0.02 . For the same load, let a 120-V supply be used with a total wire

Explain a tube well, Q. Explain a Tube Well? Method of restoring or inc...

Q. Explain a Tube Well? Method of restoring or increasing the capacity of tube well is known as developing a Tube Wells. This is done to eliminate bridging of fine particles on

Calculate the value of load resistance, A battery having of 5 cells with em...

A battery having of 5 cells with emf and internal resistance of every cell is 1.5V and 0.25Ω connected in series. If the current flow by load resistance is 1.5A, calculate the valu

Three phase power measurement, what is the relationship between the inducta...

what is the relationship between the inductance, capacitance and resistance in the 2-wattmeter experiment?

Explain temperature dependency in semiconductors, Explain temperature depen...

Explain temperature dependence of electrical resistivity and conductivity in semiconductors. The electrical conductivity of the semiconductors changes considerably with temper

Drive operating envelopes and induction machines, Solve using data from the...

Solve using data from the DC machine data sheet, using the "hot" resistance value for all calculations. Note that the value of K on the sheet is for rated (100%) field flux.  Assum

Specific core indicators method, Specific Core Indicators Method This ...

Specific Core Indicators Method This technique emphasizes to assign the responsibility and create the accountability. It is possible in which for any of the main indicators, t

Find whether the load impedance is capacitive or inductive, Q. When the two...

Q. When the two-wattmeter method for measuring three-phase power is used on a certain balanced load, readings of 1200W and 400W are obtained (without any reversals). Determine the

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd