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SECTION 4 — MAINTENANCE

4-1 General Information

The Ultra-VU is designed to need a minimum of

maintenance for long trouble-free operation. Should
repair be necessary, the technician should first read
the information in the manual concerning the circuits
in question and should follow proper procedures for
testing and replacing semiconductors. Logitek engi-
neers are readily available at the factory to provide
technical assistance both during and after the war-
ranty period.

* * * * * * * * * * WARNING * * * * * * * * * * *

The inside of the Ultra-VU contains no controls or

user serviceable parts. The cover should only be re-
moved by competent technical personnel capable of
servicing this type of equipment. Hazardous voltages
exist on the underside of some circuit cards.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * *

4-2 Fuse

The primary winding of the power transformer is

fused with a 1/2 amp slow-blow 20mm fuse housed in
a fuse holder in a slide-out drawer under the power
cord on the rear panel of the unit. It should only be re-
placed with fuses of the same type and current rating.
The power cord must be unplugged from the rear
panel to gain access to the fuse holder.

* * * * * * * * * * WARNING * * * * * * * * * * *

Do

NOT

replace the fuse without first disconnect-

ing the meter’s power cord from the wall socket, as
dangerous voltages are present which may cause
electrical shock. Always use fuses of the same value
and type as specified in this manual. Do

NOT

use

fuses of a higher value than those specified, as shock
hazard and fire hazard may result.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * *

A blown fuse is most often, although not always, a

symptom of another failure. Related circuitry should
always be carefully examined after any fuse failure,
especially if a replacement fuse also blows.

4-3 Handling of CMOS Integrated Circuits

All logic components in the Ultra-VU meter are

CMOS type integrated circuits. Even though all cir-
cuits have built in static discharge protection, special
care must be taken in the handling of these devices,
particularly in dry environments.

* * * * * * * * * IMPORTANT * * * * * * * * * *

Do

NOT

remove or handle CMOS integrated cir-

cuits except in a grounded environment which is free
of the risk of static electricity. Store such circuits on
conductive foam or in anti-static controllers. Do

NOT

store on styrofoam or other plastic sheets. Improper
handling may damage these devices.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * *

4-4 Access to Circuit Cards

Access to the circuitry of the rackmount and half-

rack meters is accomplished by removing the six
screws that attach the top cover. The inside of the
desktop unit is accessed by removing the four screws
along the edges of the bottom panel and pulling apart
the two halves of the plastic case.

4-5 Power Supply LG-253

Each Ultra-VU contains a ground isolated and fil-

tered step-down power supply to create the neces-
sary operating voltages. This supply is located on a
PCB on the right side of the meter enclosure.

Mains AC from the power entry module J2 is fed

through fuse F1, located in a drawer under the power
cord in J2, to J1 on supply card LG-253. J1 feeds volt-
age selection switch S1 which connects the dual pri-
maries of transformer T1 in series for 230VAC
operation or parallel for 115VAC operation. The dual
secondaries of T1 are wired in parallel and loaded
with a full-wave bridge rectifier RT1. The DC output of
RT1 is filtered by capacitors C1 and C2 and fed to the
red and green output pads. The voltage should be be-
tween 8 to 10 VDC with less than .5 volt of ripple.

Analog input models will also have a charge pump

consisting of IC1 and C3 that feeds filter C4 and the
black output pads. The voltage should be -8 to -10
VDC with less than .1 volt of ripple.

Jumpers soldered to the output pads feed power to

one or two meter control cards.

* * * * * * * * * * WARNING * * * * * * * * * * *

Dangerous voltages are present on the bottom of

the power supply card. Always disconnect the AC
power cord when servicing this circuit board.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * *

4-6 Analog Input Control Card LG-266

+7 VDC from input connector P4 is connected to

voltage regulators IC12 and IC5 as well as display
board connector P6. IC12 feeds the digital section of
the PCB while IC5 feeds the analog front end. -7 VDC
from input connector is connected to voltage regula-
tor IC6 which feeds the analog front end.

On power up, the DSP is kept in reset by IC8 until

the power has stabilized, ensuring a good power on
reset. IC8 also contains a watchdog timer that will re-
set the DSP if its ST pin is not taken low at least once
every 150 mSec. This pin is normally pulsed low
every 5 mSec by the left bargraph load signal.

The DSP (IC11) is clocked by a 12.288 MHz crys-

tal oscillator consisting of Y1, C26, C25 and an inter-
nal driver. IC11, Pin 43 is a buffered output of the
oscillator.

Page 9

** Ultra-VU Operation & Service Manual **

Summary of Contents for ULTRA-VU

Page 1: ...ULTRA VU LED BARGRAPH AUDIO METER Operation Service Manual Logitek...

Page 2: ...ngineer decompile disassemble or cre ate derivative works from the software You may not create copies of the software This statement will be governed by the laws of the State of Texas U S A Logitek re...

Page 3: ...Resolution Mode 7 3 8 Auxiliary Data Display 7 3 9 Changing Display Brightness 7 3 10 CLIP indicator set point 7 3 11 Resetting the Program 7 SECTION 4 MAINTENANCE 4 1 General Information 8 4 2 Fuse 8...

Page 4: ...o the ballistic standards described in IEEE document G 2 1 2 13 IEC document 268 and EBU document 3205 E This ensures that the bargraph motion will closely track other standard mechanical and elec tro...

Page 5: ...er be operated if the ambient temperature is above 55 degrees C 131 degrees F 2 5 Connecting Mains Power Connect the meter to the power mains with the en closed power cord The unit is factory set for...

Page 6: ...tches 6 7 and 8 as shown Zero Reference Setting Sw6 Sw7 Sw8 dBs below full scale Up Up Up 10 dB Up Up Dn 12 dB Up Dn Up 14 dB Up Dn Dn 16 dB Dn Up Up 18 dB Dn Up Dn 20 dB Dn Dn Up 20 dB Dn Dn Dn 20 dB...

Page 7: ...single red segment that maintains the highest PPM reading for a user se lectable amount of time If the holding period expires before the PPM dot equals or exceeds the peak hold dot then the peak hold...

Page 8: ...e meter in one second inter vals This function is active even when the received data is invalid Sample Rate Data Display Label Meaning 32 0 32 000 Hz 1 44 0 44 056 Hz 1 44 1 44 100 Hz 1 47 9 47 952 Hz...

Page 9: ...may damage these devices 4 4 Access to Circuit Cards Access to the circuitry of the rackmount and half rack meters is accomplished by removing the six screws that attach the top cover The inside of t...

Page 10: ...irst powered up it may generate noise up to 70 dBFS until it undergoes a calibration cycle 4 7 Digital Dual Input Control Card LG 265 Power from input connector P4 is connected to voltage regulators I...

Page 11: ...ad pulse IC1 and IC2 drive the upper bargraph left chan nel IC3 and IC4 drive the lower bargraph right channel IC5 drives the scale indicator LEDs along the bottom edge of the display Avoid removing a...

Page 12: ...500 Connectors P1 3 pin large header locking PN MLSS156 3A J1 3 pin large socket PN CE156F20 3A J2 Power entry module fuse holder SR 6200 4115 Switches S1 Slide DPDT CK L202 121MS02QE Transformers T1...

Page 13: ...s J1 2 Female XLR NT NC3FK H J3 3 pin socket PN CE100F28 3A J4 3 pin large socket PN CE156F20 3A J6 7 10 pin dual row socket PN 050 010 455 P3 3 pin header PN MFSS100 3A P4 3 pin large header PN MFSS1...

Page 14: ...crystal CT MP122 Resistors R1 2200 R2 110 R3 75 R4 1000 R5 6 100K R7 8 100K 2 5 position bussed CT 770 61 R104 R9 10 20K 8 position isolated SMD CT 767163203G R11 12 10K Switches S 1 8 Dip switch blo...

Page 15: ...NMC1206Z5U104M50T C19 01uf AV 12065E103MATMA C20 21 1uf 35V tantalum AV TAP105K035HSB C22 01uf AV 12065E103MATMA C23 1 uf 50V ceramic SMD NC NMC1206Z5U104M50T C24 25 470pf 100V ceramic SMD AV 12061A47...

Page 16: ...Microchip Technology Inc Chandler AZ MM Maxim Sunnyvale CA MO Motorola Semiconductor Products Phoenix AZ MP Mepcopal San Diego CA MU Murata Electronics Smyrna GA NC NIC Components Corp North Amityvil...

Page 17: ...SECTION 7 Diagrams Page 17 Ultra VU Operation Service Manual...

Page 18: ...Ultra VU Operation Service Manual Page 18...

Page 19: ...Page 19 Ultra VU Operation Service Manual...

Page 20: ...Pin5 5VDC The Mode button momentarily connects Pins 1 2 The Peak Hold button momentarily connects pins 3 2 Connect pins 4 5 to display the analog input when a valid digital input is present automatic...

Page 21: ...Page 21 Ultra VU Operation Service Manual...

Page 22: ...Ultra VU Operation Service Manual Page 22 1 2 3 4 5 6 Connector P3 Pin2 Pin5 5VDC The Mode button momentarily connects Pins 1 2 The Peak Hold button momentarily connects pins 3 2...

Page 23: ...Page 23 Ultra VU Operation Service Manual...

Page 24: ...Ultra VU Operation Service Manual Page 24...

Page 25: ...Page 25 Ultra VU Operation Service Manual...

Page 26: ...Ultra VU Operation Service Manual Page 26...

Page 27: ...Page 27 Ultra VU Operation Service Manual...

Page 28: ...Ultra VU Operation Service Manual Page 28...

Page 29: ...Seller s obligation under this warranty shall be limited to such adjustment as Seller may ob tain from the original manufacturer This limited warranty is void if equipment is modi fied or repaired wit...

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