Materials on imported phones have repeatedly been published in "Amateur Radio" in the past and this year. The most serious publication about the repair THAT imported was published in No. 10/92 G. under the heading "CRUZ - in import phone". Unfortunately, the choice of materials on this topic " the editorial was not there, and to help many owners of defective vehicles wanted, and that is why this article without the signature of the author, "market" version, was published.
Today's edition has a more robust material about the repair of imported phones, and previously unknown author "market" material kindly provided by "RL" for a more detailed description of the method of repair, amendments sent some inaccuracies former publications, and developed additional figure of the PCB with the transitional contacts for independent foreign dialers domestic chip type KRUG.
The difficulty of replacing imported integral dialers lies only in the fact that the soldering pins of the chip CU UR 1 does not coincide with any of the foreign chips. However, there is always a place for a small riser, which can, for example, be placed between the telephone earpiece and the main Board, as shown in Fig. 1.
Fig.1
The design of the riser and the scheme of its circuit Board shown in Fig.2, a schematic diagram is in Fig.3. On Board are the chip CRUZ transistors and key elements of the correction and protection, as well as 1 2 contact pads to which is soldered a transition wiring of thin wires. Scheme abbreviations: IR-switching key (dial), OTB - end call, the P - switch, +EP - positive power wire.
Fig.3
Wiring pads riser contact pads of the main Board, which is not defective chip dialer, are given in table.1.
Table.1
For example, the contact area 4 on adapter Board (next to the output 22 of the chip CRUZ), must be connected to the contact pad from the output 16 of the chip KS5805A on the main Board. Similarly connects this contact with the place from wybicki conclusions, 14, 1, 18 chips WE9192B, UM9151-3, UM9151 respectively.
In order for the phone to redial the last dialed number, you need to make changes to type-setting Board. On this Board it is necessary to break a track that leads from the pads 7 to the button "#", and solder the broken end of the track from this button to the pad 3. Scheme changes in the joints dial pad circuit Board with contact pads shown in Fig.4.
Figure 4
If all connections are made correctly, and the number is not dialed, then the cause may be low voltage on the Zener diode riser (less than 1.5 In). In this case, it is necessary to increase the current through the Zener diode, reducing the resistance of the resistor R1 do,2...10 kOhm. (Fig.5). In rare cases (if the tube is removed, and the tone is not) you need to add a resistor R2, a resistance of 100 to 300 ohms.
Fig.5
Pinout foreign transistors used in phones-tubes, and their domestic counterparts are given in table.2.
Table.2
Author: A. Kisliuk, Moscow; Publication: N. Bolshakov, rf.atnn.ru