Patent ID: 8552845
Filing Date: 2013-10-08
Classification: B60R

Abstract:
1. A vehicle burglar alarm circuit comprising: a transformer which includes an input section having first to fourth taps and a center tap, wherein the number of turns of a coil between the first tap and the second tap is greater than the number of turns of a coil between the third tap and the fourth tap, and the center tap is provided at a center point of the coil between the first tap and the second tap and the coil between the third tap and the fourth tap, and an output section magnetically coupled with the input section and connected with a sounding body; a first power source, configured to be attachable and detachable, including one electrode connected to the center tap to output a first DC voltage; a second power source including one electrode connected to the center tap to output a second DC voltage which is lower than the first DC voltage; a sounding body driving unit which includes a first driving switch having one terminal connected to the first tap of the transformer and another terminal connected to the other electrode of the first power source, a second driving switch having one terminal connected to the second tap of the transformer and another terminal connected to the other electrode of the first power source, a third driving switch having one terminal connected to the third tap of the transformer and another terminal connected to the other electrode of the second power source, and a fourth driving switch having one terminal connected to the fourth tap of the transformer and another terminal connected to the other electrode of the second power source; a power source selection unit which selects one of the first power source and the second power source as a power source that supplies a power to the transformer; and a controller which controls on and off of the first to fourth driving switches of the sounding body driving unit, wherein, if the first power source is selected, the controller alternately turns on and off the first and the second driving switch, and turns off the third and the fourth driving switch to supply a power from the first power source to the sounding body; and wherein, if the second power source is selected, the controller alternately turns on and off the third and the fourth driving switch, and turns off the first and the second driving switch to supply a power from the second power source to the sounding body.