Powersupplies - Mitel SX-200 Practices

Peripheral Devices
The serial/parallel converter converts serial data from the W-232 port to parallel for
the processor, and parallel data from the processor to serial for the W-232 port. In
asynchronous mode, the microprocessor does the conversion; in synchronous mode,
shift registers and latches interface the TxD and RxD lines with the databus to the
processor.
The Phase Lock Loop and Clock circuits synchronize the receive data rate of the data
set to the rate of the received data from the other device.
The DNIC Interface Circuit provides the interface to the PABX; its clock signals operate
the dataset in either set or system mode.
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The W-232 Interface contains the drivers and receivers that buffer the signal lines.
It also contains a loopback circuit which can connect together transmit data from the
microcontroller to receive data to the microcontroller (RxD to TxD) for self-testing
functions.
The Power Supply receives unregulated ac voltage and rectifies it to become +I 2 vdc
unregulated, -12 vdc unregulated, and +5 vdc regulated for logic circuits.
Power Supplies
15.12 The Standalone DATASET 2103 receives its power from a plug-in transformer which
supplies 9 vat to a power connector on the back of the set. Circuitry within the data
set converts this to the required dc voltages.
The Rack Mounted DATASET 2102 receives 9 vat from the power supply of the
DATASHELF 00. Circuitry on the card converts this to the required dcvoltages. Refer
to DATASHELF 9100 in this Practice, for further information,
126 15-18 Revision 0 9109-096-12&NA Issue 1