Central Battery Telephones
The predominating feature of our Central Battery Telephones is the circuit arrangement, which we have decided to adopt as our standard in view of the consistent excellence of results derived from long and exhaustive practical tests. The efficiency of this circuit depends upon two pieces of Apparatus, viz., the Peel-Conner Transmitter and Electro Magnetic Receiver; realising that these are the only parts of a Central Battery Telephone necessary for actual use, we set out to design them in such a way as to render auxiliary apparatus in the transmission circuit - such as Condensers and Induction Coils - entirely superfluous.
Our present arrangement is the successful issue of these endeavours, and we specially invite prospective customers to make thorough practical tests with Peel-Conner Telephones in comparison with other Instruments, whether for local or long distance service, and on both short and long subscribers lines. The result will conclusively prove that under all conditions, using actual working tests, both transmitting and receiving are fully equal in every respect to the best Instruments of more complicated and expensive design, and vastly superior to the majority of them. It will further be noticed that the objectionable "side-tone" so prevalent in other forms of Central Battery Instruments is reduced to a minimum in ours.
The sole use of Condensers and Induction Coils in the transmission circuit of Central Battery Instruments has been for the purpose of preventing the passage of battery current through the receiver; by using the battery current to magnetise the receiver instead of the permanent magnet we have turned this energy into direct use and thus eliminated the Induction Coil and Condenser.
It will be observed that our specification of equipment in each case calls for a condenser of 1 m.f. only, the sole function of which is to prevent the passage of the central battery current through the ringer, and, as a 1 m.f. condenser is quite sufficient for the necessary current to operate the ringer, it will be readily understood that a larger size is superfluous. In addition, the smaller capacity condenser offers greater impedance to the voice currents in the Ringer Bridge thus decreasing attenuation.
Only one contact is required in the Hook Switch, and for Desk Set Instruments a two-conductor cord is all that is necessary between the set and the Bell and Condenser Box. This greatly simplifies connecting up, and makes it quite impossible for errors in this respect to creep in, as it is immaterial which conductor of the cord is attached to the A or B line. It also provides the advantage of making it possible to connect an extension Instrument direct to the line wires at any convenient point, a pair of wires only being necessary.
In summarising the points we have discussed in favour of Peel-Conner Standard Central Battery Telephones, we invite the intending purchaser to consider their influence on initial outlay and up-keep expense. The elimination of the Induction Coil, and the substitution of a two-conductor for a three-conductor cord in the complete Desk Set, enables us to sell at a lower first cost, and provides the purchaser with means for effecting appreciable savings on his yearly maintenance account. Fewer parts, fewer risks of breakdown, simpler design, and complete accessibility mean saving in time and trouble. The finest material and workmanship only are used, and we GUARANTEE Peel-Conner Telephones to give satisfaction.
Taken from the Peel Conner Telephone Works Ltd Bulletin No. 2 - dated 1911
Last revised: January 25, 2011