Power cable

A power cable is configured for connecting at least one electrical device to a power source. The power cable includes an input terminal, at least one output terminal, a power transmitting wire, a switch, a voltage setting device, a voltage sampling device, a voltage comparing device and a power supply. The power transmitting wire connects the input terminal and the output terminal via the switch. The voltage sampling device is configured for sensing a voltage of the output terminal. The voltage comparing device is configured for comparing a preset voltage stored in the voltage setting device and the sampled voltage sensed by the voltage sampling device to turn on or turn off the switch according to the compared result. The power supply is configured for reducing the voltage of the power source to the rated voltage of the voltage comparing device to power the voltage comparing device.

BACKGROUND

1. Technical Field

The present disclosure relates to cables and, particularly, to a power cable capable of supplying multiple voltage levels.

2. Description of Related Art

Output voltages of current available household power supplies generally may be 110V or 220V. Rated voltages of current electrical devices also include 110V or 220V. As such, an electrical device may be connected to a mismatched power supply. When the electrical device is connected to a mismatched power supply, it is at risk of being damaged.

Therefore, it is desirable to provide a power cable, which can overcome the above-mentioned limitations.

DETAILED DESCRIPTION

Referring toFIG. 1andFIG. 2, a power cable1configured for simultaneously connecting a plurality of electrical devices2to a power source3includes a housing10, an input terminal11, a plurality of output terminals12(two are illustrated in the embodiment), a power transmitting wire20, and a switch30, a voltage setting device40, a voltage sampling device50, an alarm60, a power supply70, and a voltage comparing device80. The power transmitting wire20, the switch30, the voltage setting device40, the voltage sampling device50, the alarm60, the power supply70, and the voltage comparing device80are received in the housing10. The housing10defines a hole101and the voltage setting device40extends from the hole.

The input terminal11is electrically connected to the power source3. The output voltage of the power source3may be 110V or 220V. In the embodiment, the output voltage of the power source3is 220V.

Each of the two output terminals12is connected to a corresponding electrical device2. In the embodiment, the two electrical devices2are a computer host and a display.

The power transmitting wire20includes a neutral wire21, an ground wire22, and a live wire23. The neutral wire21and the ground wire22make a parallel connection between the input terminal11and the output terminals12. The live wire23connects the input terminal11to the output terminals12through the switch30. In the embodiment, the switch30is a relay.

The voltage setting device40includes a first jumper41, a second jumper42, and a jumper cap43. The first jumper41and the second jumper42each have a first electrical terminal and a second electrical terminal. The first electrical terminals of the first jumper41and the second jumper42are grounded. The second electrical terminals of the first jumper41and the second jumper42are connected to a corresponding first pin81and second pin82of the voltage comparing device80respectively. The first jumper41and the second jumper42each have two conductive sheets. The jumper cap43is configured for selectively and electrically bridging the two conductive sheets of the first jumper41or the two conductive sheets of the second jumper42. The voltage setting device40is configured to set a preset voltage and transmit the preset voltage to the voltage comparing device80. The preset voltage is compared with the output voltage of the power source3by the voltage comparing device80(seen below). If the rated voltage of the electrical devices2is about 110V, the two conductive sheets of the first jumper41are bridged to provide a low electric level signal to the first pin81. If the rated voltage of the electrical devices2is about 220V, the two conductive sheets of the second jumper42are bridged to provide a low electric level signal to the second pin82.

The voltage sampling device50is electrically connected to the input terminal11to sample the output voltage of the power source3and output the sampled voltage to a third pin83of the voltage comparing device80. When the output voltage of the power source3is 110V, the voltage sampling device50will provide a low electric level to the third pin83. When the output voltage of the power source3is 220V, the voltage sampling device50will provide a high electric level to the third pin83.

The alarm60is electrically connected to a fifth pin85of the voltage comparing device80and configured for sending an alarm according to a control signal from the fifth pin85. In the embodiment, the alarm60may be but not limited to a buzzer or a light emitting diode (LED).

The power supply70is electrically connected between the input terminal11and a sixth pin86of the voltage comparing device80and configured for converting the output voltage of the power source3to a rated voltage of the voltage comparing device80so as to appropriately supply power to the voltage comparing device80.

The voltage comparing device80also includes a fourth pin84connected to the switch30. A chart is stored in the voltage comparing device80. The chart shows that the low electric level of the third pin83is matched with the low electric level of the first pin81and the high electric level of the third pin83is matched with the low electric level of the second pin82. When the voltage comparing device80is powered by the power supply70via the sixth pin86, the voltage comparing device80compares the electric level of the first pin81or the second pin82and the electric level of the third pin83. Moreover, it turns on the switch30when the electric level of the first pin81or the second pin82matches that of the third pin83. Otherwise, the voltage comparing device80turns off the switch30and triggers the alarm60to send an alarm via the fifth pin85in case the electric level of the first pin81or the second pin82are not matched with that of the third pin83. In the embodiment, the voltage comparing device80is a single chip micyoco (SCM).

In use, the input terminal11is connected to the power source3, and the comparing device80is powered by the power supply70. The voltage sampling device50will provide a high electric level to the third pin83. When the rated voltage of the electrical devices2is about 110V, the two conductive sheets of the first jumper41are bridged to provide a low electric level signal to the first pin81. The voltage comparing device80compares the electric level of the first pins81and the third pin83according the chart to control the switch30to turn off and triggers the alarm60to send an alarm via the fifth pin85. When the rated voltage of the electrical devices2is about 220V, the two conductive sheets of the second jumper42are bridged to provide a low electric level signal to the second pin82. The voltage comparing device80compares the electric level of the second pin82and the third pin83according the chart to control the switch30to turn on.

It will be understood that the above particular disclosures and methods are shown and described by way of illustration only. The principles and the features of the present disclosure may be employed in various and numerous disclosures thereof without departing from the scope of the disclosure as claimed. The above-described disclosures illustrate the scope of the disclosure but do not restrict the scope of the disclosure.