Patent ID: 6647120
Filing Date: 2003-11-11
Classification: H04R

Abstract:
A thermal protection circuit for a loudspeaker system having a loudspeaker driver mechanism adapted for connection to a signal supply mechanism for providing an electrical signal to the loudspeaker driver mechanism, the thermal protection circuit comprising:an input adapted to receive an electrical signal from a signal supply mechanism; an output adapted to apply the electrical signal to the loudspeaker driver mechanism; a load device connected in series with the input and the output for reducing a power of the electrical signal before reaching the loudspeaker driver mechanism; and a first normally closed, thermally sensitive switch connected in parallel with the load device and thermally connectable to the loudspeaker driver mechanism such that heat generated by the loudspeaker driver mechanism is at least conductively transferable to the first switch, the first switch being changeable between a closed state wherein the load device is at least substantially bypassed, and an open state wherein the electrical signal is at least substantially directed through the load device when a temperature of the first switch is above a predetermined temperature and the electrical signal is above a first predetermined signal level.