In the last decade in the development of telecommunication traced qualitative changes associated with the development of telephone equipment on the new microelectronic elemental base. An example of such equipment is the director switch «Don». The switch has a unit tastaturnogo set that provides additional types of maintenance services and less time dialing.
On the set of ten-digit number by a tastaturnogo dialer spent about 6.5 seconds, which is twice less than that through the disk. Accordingly, reduced setup time, and class of station devices. In addition, tastaturny dialer has several other advantages. In particular, while dialing via keypad does not depend on its constituent figures, t. E. The rooms are not divided into «convenient» (consisting of digits from 1 to 5) and «inconvenient» (from 6 to 0), the button can be pressed at any speed. It reduces the net error.
Use tastaturnom dialer allows storage devices to coordinate the speed dial on the keyboard with the speed of the formation of the output signals on the PSTN line. At the same digits stored in memory at an arbitrary rate, and played at a frequency corresponding to the speed of the electro-mechanical and other systems operated by ATS.
It can be used as part of any switch that has the power from AC, 50 Hz. The advantage of this scheme is the complete absence of elements of setting, as the duration of the dial pulse period of the journey and mezhseriyny interval formed by a digital circuit as derived clock frequency of 100 Hz. The list of elements used in the block TNN is shown in Table.
When an electronic unit composed TNN switches without stabilized voltage source 5, the power supply is required.
Block tastaturnogo dialer has the following characteristics information (input «C» — 0).
ki + 5V ± 5%, the memory capacity of 15 characters, while the pulse circuit contact TNN 40 ms, during his opening 60 ms. mezhseriyny interval of 640 ms.
The device operates as follows (see. Fig. 1) When you press one of the buttons «1». «0» at the outputs transformed into a binary coded decimal (D1 1, D1 2. D2, D3) shows information on the dialed digits in the four bit binary code converter C outputs this information is supplied to data inputs of RAM random access memory (D7), and OR circuit (D6), which appears at the output signal of logic 0. A protection device (010.1), this signal is supplied to the count input trigger D16.1. Last switches at the input «1» signal appears trigger D16.2 1.
The diagram of the trigger shown in PHC 016.2 3. The figure shows that when the output «Q» appears briefly 016.2 trigger a logic 0, there is a record dialed digit in the register RAM. Memory register number is determined by the position of the register recording the RE (D11), the currently connected through inverters D15 to the address inputs A1 ..A4 RAM. If registers of falling writing and reading are the same, the output device matching CSS (D13) signal appears logical I. Triggers D14 D14 1 and 2 are in the ground state, and the counter circuit D12 is able to record.
On the falling edge of the output pulse «Q» DI6.2 trigger switch RH. The output of the device matches appears O. This series switches and triggers D14.1 D14 2. The first translation of the counter D12 in reading mode, the second — the selection circuit address registers (D15, D19) to position RE selection.
Furthermore, the input «V» generating circuit mezhseriynogo interval (D4) supplied signal authorizing account clock. After counting 64 pulses (640 ms) 04 switches to state 1 and the trigger 05.1 authorizes the inclusion of counter G8, intended to generate pulse dialing. The output «4» of the counter 08 pulse sequence appears. When the number of pulses issued line becomes equal to the digit stored in the counter 012, the output 15 ‘of this counter appears 0 signal, which triggers 014.1 0142 and transferred to the zero state. This 012 is switched to the recording information on the inputs of the «O» and the framework for selecting the counters — in the selection status register read (MS).
If to this point has been pressed on the keyboard is still at least one button and the information is similar to the previous written in the register of RAM, then the input of the «O» of the counter 012 displays the information on the following figure recorded and RAM. Furthermore, when a G on the output «3 = 15» counter 012 trigger 05.1 switches to a zero state and stored therein until such time as the output «RH» counter 017 appears pulse (this pulse appears after 640 milliseconds, ie. e., after the read pulses 64 of the reference frequency).
While trigger 05.1 is at 0, the counter 08 is in the recording mode information (input «C» — 0) and counts pulses arriving at the input «1». After 640 ms, the counter 08 starts counting, and outputs a line following a series of pulses dialed. Thus, the output «6» of the logical NAND element (09 2) there are two series of pulses corresponding to the dialed digits, with an interval of 640 ms between batches. Similar to the previous written and read subsequent digits of the called number.
TNN stop occurs at the coincidence of the numbers recorded in the registers RA and MS. Upon completion of a series of pulses issued by line while the trigger switch 05.1, and the read register 017. Since the register readings at this point are the same, the output signal 013 appears 1, which is input to the counter 04, thereby stopping the bill received pulses. 05.1 trigger will be in state 0 as long as the counter 04 starts to count at its output «P63» appears in a short pulse. This will happen when the evidence registers records and accounts will vary.
In the «Repeat» dialer is activated by briefly pressing the corresponding button.
This flip-flop RS and 05.2 are set to 0. The output «6» element 09 appears sig nal 1, opening the corresponding contact pulse dialer. After 640 ms Trigger May 2 switches to 1, 1) 5.1 — 0 (occupation of station equipment). After subsequent 640 msec 05.1 trigger switch again in position 1 and the circuit starts to produce TNN line as described series of dial pulses recorded in the RAM. If the repeat button is pressed, another digital keyboard, the reading of the figures in this line, and so on. D.
By briefly pressing the «Reset» trigger 010.2 switches to state 0. If the nose of the 1st press one of the numeric keypad, resets the RP and RS and TNN circuit starts again (from the original state). If the nose 1C button «Reset» push button «Repeat», the scheme will operate similarly to «repeat» without pressing the «Reset», t. E. Stored in the RAM last dialed local phone number is stored until the next number, and can be repeated by pressing one «Retry» button.
The electronic unit TNN as a pulse (IR) and shunt (HQ) contacts used reed relays RES-64A RS4.569.724 connected to the outputs of the eponymous bloc TNN. The unit does not require special regulation and works immediately after power-up. Because of this it is possible to design your own in a race.