Patent Publication Number: US-5833493-A

Title: DC power connecting cable with errorproof indication

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a DC power connecting cable including light emitting elements, a buzzer and an interrupter. In the case where the wire connections to the normal and malfunctional power supplies are correct, the light emitting elements emit light to show the correct connection. In the case of incorrect connection, the buzzer emits a warning sound and the interrupter disconnects the wires from the power. 
     In a conventional external power jumper cable system for car, two ends of two parallel connecting wires are disposed with clips for clipping the positive and negative terminals of the normal and malfunctional batteries to form a circuit. It often happens that the clips are connected in reverse, which can result in damage to the circuit systems of both the impaired car and the rescue car. 
     SUMMARY OF THE INVENTION 
     It is a primary object of the present invention to provide a DC power connecting cable with errorproof indication including light emitting elements, a buzzer and an interrupter. In the case where the wire connections to the normal and malfunctional power supplies are correct, the light emitting elements emit light to show the correct connection. In the case of incorrect connection, the buzzer emits a warning sound and the interrupter disconnects the wires from the power supply to protect the car circuit from being damaged by high current levels. 
     The present invention can be best understood through the following description and accompanying drawings, wherein: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the present invention; and 
     FIG. 2 is a circuit diagram of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIGS. 1 and 2, the present invention includes a set of battery connecting conductors 1 and a polarity indicator device 2. The battery connecting conductors 1 are composed of a positive battery connecting wire 11 and a negative battery connecting wire 12 parallel thereto. Two ends of the positive and negative power connecting wires 11, 12 are respectively disposed with donor battery end clips 111, 112 and depleted battery end clips 121, 122 for clipping the terminals of the batteries of the rescue car and the impaired car. The polarity indicator device 2 is composed of a donor battery indicating means 21, a depleted battery indicating means 22, and an override protective means 23. The override protective means 23 includes two override interrupters 231, 232 disposed between the clips of the positive and negative battery connecting wires 11, 12, respectively. The donor battery indicating means 21 is formed by a resistor R1 and a light emitting diode LED1 serially connected therewith. The LED1 is positively connected between the positive and negative battery connecting wires 11, 12 (The P pole of LED1 is connected to the positive battery terminal, while the N pole is connected to the negative battery terminal) near the donor battery end. The depleted battery end indicating means 22 is formed by a resistor R2, a light emitting diode LED2 serially connected therewith and a buzzer 221 connected in parallel with the LED2. The LED2 is positively connected between the positive and negative battery connecting wires 11, 12 near the depleted battery end of wires 11, 12. The buzzer 221 is negatively connected therebetween, beside the LED2. 
     In use, the clips 111, 121 of the donor battery of the connecting wires 11, 12 are used to clip the positive and negative terminals of the donor battery (for example, the battery of a rescue car). When the clips are correctly connected to the batteries, a positive bias voltage between the positive and negative battery connecting wires 11, 12 is exerted on the LED1 to energize the same. At that moment, a light is emitted to indicate that the connections to the donor battery are correct. When the clips are incorrectly connected to the batteries, the LED1 suffers a negative bias voltage and no light is emitted. At the same time, the buzzer receives a positive bias voltage, causing it to emit a warning sound. Similarly, the clips 112, 122 of the depleted battery end of the connecting wires 11, 12 are used to clip the positive and negative electrodes of the depleted battery (for example, the battery of an impaired car). When the clips are correctly connected, a positive bias voltage is exerted on the LED2 to energize the same. At the same time, a light is emitted to indicate that the connections to the depleted battery are correct. In this instance, normal charging can be performed. 
     When connections to the donor battery are correct and the connections to the depleted battery are incorrect, the buzzer receives a positive bias voltage, causing it to emit a warning sound. Also, a high current level will occur due to a short circuit between the positive and negative battery connecting wires 11, 12. At the same time, the override interrupters 231, 232 can disconnect the positive and negative battery connecting wires 11, 12 in time, so as to avoid damage to the circuit of either car. 
     It should be noted that the above description and accompanying drawings are only used to illustrate some embodiments of the present invention, and are not intended to limit the scope thereof. Any modification of the embodiments should fall within the scope of the present invention.