TAG MCLAREN AUDIO 100 5R Series, Руководство по обслуживанию

Страница: 12 / 34

F3 series 100X5R service manual 8
2. Clean relay switches OFF
3. After a short delay, dirty relay switches OFF
This allows the dirty relay to handle all of the ‘hard’ load conditions, with the clean relay being
protected from surges and inductive spikes. During listening evaluation it was found that relay
contacts have an effect on subjective audio quality.
Relays RL2, RL4, RL6, RL8 and RL10 are the ‘dirty’ relays.
PCB mounted 20mm fuses F1, F4, F5, F6 and F7 are the primary fuses for each of the mains
outputs for the modules 1 through 5 respectively. Each module is independently fused on the
micro controller PCB. The mains outputs from the micro controller are connected to the
transformers via soldered double insulated primary wires. SMLIVEC1 and SMNEUTRALC1
connect to live and neutral of channel one’s mains transformer respectively (and so on for the
remaining four channels).
Front Panel power switch
The power on/off switch on the amplifier front panel is connected to the micro PCB via
connector EC1. This switch does NOT switch mains potential. It switches the 5VDC power
supply to the coils of the mains relays RL1 through RL10. This isolates the channels from the
mains (as the relays switch off) but retains power to the micro controller circuits.
Micro controller auxiliary power supply
PCB mounted mains transformer T1 and its associated circuit (sheet 3 of SCH28306) provide
an auxiliary 5VDC supply which powers the microprocessor and coils of the relays mounted on
the PCB. This supply is active whenever mains is present at the IEC socket on the rear panel
of the amplifier.
The micro controller remains operational when the front panel power switch is in the OFF
position.
CAUTION - there are live voltages present on this PCB whenever the unit is connected
to a mains supply!
4.1 50 way IDC connector J1
J1 connects to a 50 way ribbon cable, which carries control signals from the micro controller to
the amplifier modules, LED display, infra-red remote receiver and TAG tronic communications
bus.
This ribbon cable is ‘split’ at various lengths so that appropriate signals may be conveniently
routed to their correct destination within the amplifier. The block diagram shows the connection
from the micro controller to each of the five amplifier modules, the array of LEDs (power and
channel status), the IR remote and the TAG bus. The pin numbers at each end of each
connection are labelled.