Co-om-6605. book

Download 117.65 Kb.
View original pdf
Size117.65 Kb.
1   2   3   4   5   6   7   8   9   ...   17
2.2 G
The main function of the HLB Unscrambler is to provide a means of communication within a
Hyperbaric Lifeboat. There are two main sections to the Unscrambler, the power supply section and the PCB/Audio section.
Within the 19” rack enclosure are several Printed Circuit Boards (PCB’s) that provide the function of helium speech unscrambling as well as routing for the audio signals. There is a digital signal processor (DSP) PCB which digitally corrects the helium speech effect on the divers voice (Channel) when the unscrambler is turned on. There are five modular PCB cards that fit onto a main routing or "backplane" PCB. The backplane
PCB is the largest PCB in the unscrambler and is responsible for connecting and routing signals between the different cards inside the unscrambler. Three of the these cards are the audio module
PCB's. The audio module PCB's are responsible for the volume control for each of the divers channels. The other two cards are the audio mixing PCB which mixes the three audio signals before they are unscrambled via the DSP PCB and the input transformer PCB which controls the PTT
functions, the VU display and houses the audio input transformers.
The power supplies are mounted onto an acetal plate along with the DSP power supply. There are three DC-DC converters which convert the incoming 24Vdc supply to +12Vdc and -12Vdc (the third is a supply for the DSP). The DSP power supply has a PCB that converts the 12Vdc voltage down to
7Vdc for the DSP PCB.
The front panel contains all the main user interface elements that are used to adjust the operating parameters of the unscrambler and is split into two main sections. The section on the left of Fig is the power and audio controls. This section contains the controls for the audio functions of the unit.
The adjustable gains, PTT switches and round-robin functionalities are all controlled from the front panel.
The right hand side of Fig 2.2 shows the DSP interface which contains the Unscrambler on/off button and the DSP controls. The DSP has a set of unscrambling parameters that can be adjusted.
The user interface is displayed on the LCD. The keypad below the LCD will allow the user to navigate through the unscrambling properties and adjust to suit. The depth control is controlled via the depth potentiometer which will update the DSP and the LCD will give a readout of the current depth setting.
Fig 2.2 Front Panel

Chapter 2
CO-OM-6605 R0
(Intentionally Blank)

1   2   3   4   5   6   7   8   9   ...   17

The database is protected by copyright © 2017
send message

    Main page

Harley Davidson