Methods of testing a connection between speakers and a power amplifier and devices therefor

1. A method of testing a connection between a speaker and a power amplifier which includes a booster power source which boosts a battery voltage, a power amplifier integrated circuit (“IC”) which operates at a voltage boosted by the booster power source, and a connection terminal which connects the power amplifier IC with the speaker, and which determines that short-circuiting occurs on a ground side when a voltage of the connection terminal is lower upon comparison of a midpoint potential of an operation voltage of the power amplifier IC and a terminal voltage of the connection terminal, the method including:

switching a voltage for a power amplifier IC from a booster power source to a battery voltage when a connection test of the speaker is conducted; and

performing the determination using a midpoint potential of a battery voltage as the midpoint potential.

2. The method of claim 1 , wherein a speaker connection test with respect to the power amplifier is conducted in a speaker connection testing processing unit provided in the power amplifier.

3. The method of claim 1 , wherein a speaker connection test with respect to the power amplifier is conducted by a speaker connection testing device which is separate from the power amplifier.

4. The method of claim 1 , wherein, when a speaker connection test with respect to the power amplifier is finished, a voltage for a power amplifier IC is switched from a battery voltage to a booster power source side.

5. The method claim 1 , wherein the power amplifier further comprises a plurality of power amplifier ICs that match a plurality of speakers in number, and

wherein, upon the speaker connection test, the power amplifier ICs are sequentially selected and tested.

6. The method of claim 1 , wherein when a test result is outputted to an outside, the stored test result is read and outputted.

7. A speaker connection testing device for a power amplifier which includes a booster power source which boosts a battery voltage, a power amplifier IC which operates at a voltage boosted by the booster power source, and a connection terminal which connects the power amplifier IC with the speaker, and which comprises a speaker connection test processing unit which determines that short-circuiting occurs on a ground side when a voltage of the connection terminal is lower upon comparison of a midpoint potential of an operation voltage of the power amplifier IC and a terminal voltage of the connection terminal,

wherein in the booster power source, a battery voltage pull-in unit configured to pull in a battery voltage is provided in parallel to a boosting unit which boosts a battery voltage, and a switching unit is provided that is configured to switch a supply voltage from a booster power source to a power amplifier IC, to the booster unit or to the battery voltage pull-in unit; and

wherein upon a connection test of a speaker, the speaker connection test processing unit is configured to make the switching unit switch a voltage for a power amplifier IC to a battery voltage, and to perform the determination using a midpoint potential of a battery voltage as the midpoint potential.

8. The speaker connection testing device of claim 7 , wherein the speaker connection test processing unit is provided in a power amplifier.

9. The speaker connection testing device of claim 7 , wherein the speaker connection test processing unit is provided in a speaker connection testing device which is separate from a power amplifier.

10. The speaker connection testing device of claim 7 , wherein, when a speaker connection test with respect to the power amplifier is finished, the switching unit is configured to switch a voltage for a power amplifier IC, from a battery voltage to a booster power source side.

11. The speaker connection testing device of claim 7 , wherein a plurality of power amplifier ICs matching a plurality of speakers in number are provided and a test channel specifying unit provided in the speaker connection test processing unit is configured to sequentially select a power amplifier IC to conduct a speaker connection test.

12. The speaker connection testing device of claim 7 , wherein the speaker connection test processing unit further comprises a test result storage unit configured to store a test result,

wherein a test result outputting unit is configured to read the stored test result from the test result storage unit and to output the test result.