LEM PEGASUS 212 - Output Performance and Noise Tests; Burn-in and Acoustic Verification

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b) "06" if the RS485 OUT test passes.
c) "E6" if the RS485 OUT test fails.
FUNCTIONAL TEST
12) Restore or disconnect the RS485 test circuitry.
13) Connect the audio generator set it to 1KHz 0dBu (775mV
RMS
)sinusoidal signal,
level set to zero.
14) Connect the oscilloscope probe 1 clip to L- and tip to L+, probe 2 clip to L- and tip
to L+, initially set it to 10V/div. 200µS/div. and move the vertical scale from 5 to
20V/div. when required.
13) Press again the ENTER & SEL buttons simultaneously:
a) the COMM led must switch off and after some seconds the SIGNAL/CLIP RED
led must lights up.
b) The display shows "07".
Verify the POWER OUTPUTS:
c) the amplifier LOW & HIGH power outputs must be symmetrical referring to
GND, without any detectable distortion and oscillation.
CH1 LOW AMPLIFIER TEST
15) Verify that the LOW amplifier output signal has an amplitude of 66Vpp.
16) Turn down the generator, connect the 8ohm load resistor and increase the input
signal until the scope screen shows 66Vpp without any detectable distortion.
17) Turn down the generator, then disconnect the 8ohm load resistor and set up the
signal to 0dBu.
18) Switch alternatively the generator frequency from 1KHz to 100Hz: no level changes
referring to 1KHz level must be detectable.
CH2 LOW AMPLIFIER TEST
19) Verify that the HIGH amplifier output signal has an amplitude of 66Vpp.
20) Turn down the generator, connect the 8ohm load resistor and increase the input
signal until the scope screen shows 66Vpp without any detectable distortion.
21) Turn down the generator, then disconnect the 8ohm load resistor and set up the
signal to 0dBu.
22) Switch alternatively the generator frequency from 1KHz to 100Hz: no level changes
referring to 1KHz level must be detectable.
23) Check if CH1 & CH2 are out of phase.
SIGNAL/NOISE RATIO TEST
24) Disconnect all the cables from the module..
25) Press the ENTER & SEL buttons simultaneously:
a) SIGNAL/CLIP GREEN led must lights up and the display shows "07".
Check the following points:
b) Verify that the FAN is idle.
c) Verify that the S/N ratio from 20Hz to 2KHz is below 100dB.
26) Switching OFF the unit.
BURN-IN TEST
• Connect to the amplifier INPUT a pink noise generator.
• Connect two 8ohm resistive loads to the amplifier outputs.
• Switch ON the module and select PRESET no. 01.
• Increase the pink noise level until the SIGNAL/COMP RED led lights up irregularly.
• Run the burn-in test at least 3 hours verifing now and then the right operation.
ACOUSTIC TEST
• After burn-in test the amplifier module must still work properly, verify with an
acoustic test in the speaker box if all works properly and none noise must be still
audible.