Saturday, January 07, 2017

Harman kardon SUB-TS11 – Test procedure – Class D power amplifier circuit

Test Set Up and Procedure
Equipment needed:
# Function/signal generator/sweep generator
# Integrated Amplifier
# Multimeter
# Speaker cables
Initial Control Settings:
# Power Switch OFF

# Filter OFF
# Level MIN (Full CCW)
# Phase, Auto/On switches do not matter
General Unit Function (UUT = Unit Under Test)
1) From the signal generator, connect one line level (RCA) cable to the Subwoofer Line Level Input jacks L/R on the UUT. Use a Y-cable from a mono source if necessary to connect to both inputs. Do not connect to the single, purple SUB input.
2) Turn on generator; adjust to 60mV, 50 Hz.
3) Plug in UUT; turn the power switch ON. Turn LEVEL control full clockwise (MAX)
4) LED should turn from Amber to Blue (on top of UUT); immediate and vigorous bass response should be heard and felt from port tube opening.
Listen to the cabinet and drivers for any rattles, clicks, buzzes or any other noises. If any unusual noises are heard, remove woofers and test.
5) Turn off generator, turn LEVEL control of UUT full counterclockwise (MIN), and disconnect RCA cable.
6) Connect one pair of speaker cables to Speaker Level input terminal (IN) on UUT. The others end of the Cables should be connected to an integrated amplifier fed by the signal generator.
7) Turn on generator and adjust so that input 
level at the amplifier should be 1.2V, 50 Hz. 
8) Turn LEVEL control of UUT full clockwise (MAX).
9) LED should turn from Amber to Blue; immediate and vigorous bass response should be heard and felt from the port tube opening. Listen to the cabinet and drivers for any rattles, clicks, buzzes or any other noises. If any unusual noises are heard, remove woofers and test.
Sweep Function test 

1) Connect one pair of speaker cables to Speaker Level input terminal (IN) on UUT. The others end of the Cables should be connected to an integrated amplifier fed by the signal generator.
2) Turn on generator and adjust so that input level at the amplifier should 1.2V, 50 Hz.  
3) Plug in UUT; turn the power switch ON.Turn LEVEL control of UUT full clockwise.
4) LED should turn from Amber to Blue; immediate and vigorous bass response should be heard and felt from the port tube opening.
5) Sweep generator from 20Hz to 300Hz. Listen to the cabinet and drivers for any rattles, clicks, buzzes or any other noises. If any unusual noises are heard, remove woofers and test.
Driver Function test
1) Remove woofer from cabinet; detach + and - wire clips.
2) Check DC resistance of woofer; it should be 2.8 ohms +/-10%
3) Connect a pair of speaker cables to driver terminals. Cables should be connected to an integrated amplifier fed by a signal generator. Turn on generator and adjust so that speaker level output is 5.0V.
4) Sweep generator from 20Hz to 1kHz. Listen to driver for any rubbing, buzzing, or other unusual noises.

Power amplifier uses Complimentary pair MOSFET IRF640 and IRF9640
IRF640 - Power MOSFET
FEATURES
# Dynamic dV/dt rating
# Repetitive avalanche rated
# N-Channel
# Fast switching
# Ease of paralleling
# Simple drive requirements
Specification
VDS (V)
200
RDS(on) (Ohms)
VGS = 10 V 0.18 Ohm
Qg (Max.) (nC)
70
Qgs (nC)
13
Qgd (nC)
39
Configuration
Single
IRF9640 - Power MOSFET
FEATURES
# Dynamic dV/dt rating
# Repetitive avalanche rated
# P-channel
# Fast switching
# Ease of paralleling
# Simple drive requirements
Specification
VDS (V)
-200
RDS(on) (Ohms)
VGS = -10 V 0.50 Ohm
Qg max. (nC)
44
Qgs (nC)
7.1
Qgd (nC)
27
Configuration
Single
POWER AMPLIFIER CIRCUIT DIAGRAM


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