Self diagnostic speaker load impedance testing system
View Patent ↗A self diagnostic loudspeaker load impedance testing system, or Push Here Diagnostic (PHD) system, located within a mixer/amplifier for testing loudspeaker connections to the mixer amplifier during installation and maintenance. The system includes a test signal source that replaces the normal audio input to the amplifier during test. A PHD analyzer within the mixer amplifier analyzes the response of the loudspeakers and related wiring to the test signal to detect a total system impedance that exceeds the amplifier rating and to detect short circuits in the wiring. The PHD analyzer illuminates an indicator when a fault occurs. The test is initiated by depressing a momentary contact switch within the mixer amplifier housing by inserting a tool through an opening in the mixer amplifier housing.
1. A self-diagnostic speaker load impedance testing system, comprising:
a. an audio mixer/amplifier comprising a housing enclosing an audio input signal mixer coupled to an amplifier configured to be coupled to a plurality of loudspeakers;
b. a testing signal source within said audio mixer/amplifier; and
c. a test enable switch within said audio mixer/amplifier that is:
i. operable to couple a test signal from said test signal source into said amplifier to produce an amplified test signal;
ii. a momentary push button switch accessible through an opening in said housing; and
d. wherein said testing signal source within said audio mixer/amplifier comprises a direct current isolator, wherein said isolator comprises a circuit operable to isolate any direct current component of said testing signal.
2. The system of claim 1 , wherein said plurality of said loudspeakers is coupled to said mixer/amplifier, the system further comprising a diagnostic analyzer within said mixer/amplifier responsive to said amplified test signal and to a collective impedance from said plurality of said coupled loudspeakers to determine if said impedance is a correct impedance match for said amplifier.
3. The system of claim 2 , further comprising a fault indicator, in communication with said diagnostic analyzer, mounted on said housing, and operable to illuminate responsive to particular outcomes of said determination.
4. The system of claim 3 , wherein said fault indicator illuminates responsive to an impedance that is lower than the power rating of said amplifier.
5. The system of claim 2 , wherein said collective impedance includes the impedance of wiring between said mixer/amplifier and said plurality of said loudspeakers.
6. The system of claim 3 , wherein said fault indicator illuminates responsive to at least one of:
a. a short circuit in wiring between said amplifier and at least one coupled loudspeaker of said plurality of speakers; and
b. an impedance that is lower than the power rating of said amplifier.
7. The system of claim 1 , wherein said testing signal source within said audio mixer/amplifier comprises a trimmer, wherein said trimmer comprises a variable resistor operable to receive said test signal and to trim said test signal.
8. The system of claim 1 , wherein at least one speaker of said plurality of speakers comprises a power transformer having a plurality of user-selectable power taps.
9. A self-diagnostic speaker load impedance testing system, comprising:
a. an audio mixer/amplifier comprising a housing enclosing an audio input signal mixer coupled to an amplifier configured to be coupled to a plurality of loudspeakers;
b. a testing signal source within said audio mixer/amplifier;
c. a test enable switch within said audio mixer/amplifier that is:
i. operable to couple a test signal from said test signal source into said amplifier to produce an amplified test signal; and
ii. a momentary push button switch accessible through an opening in said housing; and
d. a diagnostic analyzer within said mixer/amplifier responsive to said amplified test signal and to a collective impedance from said plurality of said loudspeakers, when coupled to said mixer/amplifier, to determine if said impedance is a correct impedance match for said amplifier; and
e. wherein said testing signal source within said audio mixer/amplifier comprises a direct current isolator, wherein said direct current isolator comprises a circuit operable to isolate any direct current component of said testing signal.
10. The system of claim 9 , further comprising a fault indicator in communication with said diagnostic analyzer, mounted on said housing, and operable to illuminate responsive to particular outcomes of said determination.
11. The system of claim 10 , wherein said fault indicator illuminates responsive to an impedance that is lower than the power rating of said amplifier.
12. The system of claim 9 , wherein said collective impedance includes the impedance of wiring between said mixer/amplifier and said plurality of said loudspeakers.
13. The system of claim 11 , wherein said fault indicator illuminates responsive to at least one of:
a. a short circuit in wiring between said amplifier and at least one coupled loudspeaker of said plurality of speakers; and
b. an impedance that is lower than the power rating of said amplifier.
14. The system of claim 9 , wherein said testing signal source within said audio mixer/amplifier comprises a trimmer, wherein said trimmer comprises a variable resistor operable to receive said test signal and to trim said test signal.
15. The system of claim 9 , wherein at least one speaker of said plurality of speakers comprises a power transformer having a plurality of user-selectable power taps.
16. A self-diagnostic speaker load impedance testing system, comprising:
a. an audio mixer/amplifier comprising a housing enclosing an audio input signal mixer coupled to an amplifier configured to be coupled to a plurality of loudspeakers;
b. a testing signal source within said audio mixer/amplifier;
c. a test enable switch within said audio mixer/amplifier that is:
i. operable to couple a test signal from said test signal source into said amplifier to produce an amplified test signal; and
ii. a momentary push button switch accessible through an opening in said housing;
d. a diagnostic analyzer within said mixer/amplifier responsive to said amplified test signal and to a collective impedance from said plurality of said loudspeakers, when coupled to said mixer/amplifier, to determine if said impedance is a correct impedance match for said amplifier;
e. a fault indicator, in communication with said diagnostic analyzer, mounted on said housing and operable to illuminate responsive to particular outcomes of said determination; and
f. wherein said testing signal source within said audio mixer/amplifier comprises a direct current isolator, wherein said isolator comprises a circuit operable to isolate any direct current component of said testing signal.
17. The system of claim 16 , wherein said collective impedance includes the impedance of wiring between said mixer/amplifier and said plurality of said loudspeakers.
18. The system of claim 17 , wherein said fault indicator illuminates responsive to at least one of:
a. a short circuit in wiring between said amplifier and at least one coupled loudspeaker of said plurality of speakers; and
b. an impedance that is lower than the power rating of said amplifier.
19. The system of claim 16 , wherein said testing signal source within said audio mixer/amplifier comprises a trimmer, wherein said trimmer comprises a variable resistor operable to receive said test signal and to trim said test signal.
20. The system of claim 16 , wherein at least one speaker of said plurality of speakers comprises a power transformer having a plurality of user-selectable power taps.