Patent Application
20110316711
1. Field of the Invention
The present invention relates to a grounding device, and more particularly to a pocket grounding device without power socket.
2. Description of Related Art
A general AC outlet has an AC line wire, AC neutral wire and ground wire. The ground wire is used to connect to ground and an electronic equipment does not have electric leakage condition to harm the user when the power plug of the electronic equipment inserts into the AC outlet having ground. However, the user does not ensure whether the ground connection is good or not, since the ground wire is hidden in a casing of the AC outlet. Therefore, an apparatus that provides electronic equipment with a reliable ground, AC line and AC neutral connections.
With reference to
To overcome the shortcomings, the present invention provides a pocket grounding device without power socket for a power strip to mitigate or obviate the aforementioned problems.
The main objective of the present invention is to provide a pocket grounding device without power socket.
The pocket grounding device without power socket has a casing, an AC plug and a circuit board. The AC plug is mounted in the casing and electronically connected to the circuit board. The circuit board has a ground detecting circuit having three ports respectively connected to the AC plug, an electronic switch connected between to two of the ports and a controlling terminal thereof connected to the last port, and an indicator exposed to the casing. The indictor is driven to light at a conductive condition of the electronic switch since the AC plug connected to an AC outlet of a power strip having good grounding connection. Therefore, a user checks the LED status to judge whether the AC power strip has good grounding connection.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
With reference to
The casing (10) has two opposite faces, through hole (111) and an opening (112). The AC plug (12) mounted on the first face of the casing (11) and has a line blade (121), a neutral blade (122) and a ground blade (123).
The circuit board (13) has a ground detecting circuit having three ports (I/P_L, I/P_N, I/P_G), an electronic switch (131), an indicator (132) and a zener diode (Z1). The three ports (I/P_L, I/P_N, I/P_G) are respectively and electronically connected to the line blade (121), neutral blade (122) and a ground blade (123). The electronic switch (131) is connected between to the first and second ports (I/P_L, I/P_N) connected to the line blade (121) and the neutral blade (122). A controlling terminal of the electronic switch (131) is connected to the third port (I/P_G) connected to the ground blade (123). The indicator (132) may be an LED connected between the electronic switch (121) and the first port (I/P_L). The electronic switch (131) may be a BJT transistor having a collector, emitter and a base. That is, an anode terminal of the LED is connected to the first port (I/P_L) and a cathode terminal of the LED is connected to the collector of the electronic switch (131). The emitter of the electronic switch (131) is connected to the second port (I/P_N). The base of the electronic switch (131) is a controlling terminal and connected to the third port (I/P_G) through a first series of resistors (R3, R4). Further, the third port (I/P_G) is connected to the first port (I/P_L) through a second series of resistor (R1, R2). The zener diode (Z1) is connected between the anode terminal of the LED and the emitter of the electronic switch (131). The LED passes through the through hole (111) of the casing (11).
With reference to
Based on the foregoing description, the grounding device does not require power socket and only displays grounding status by the indicator, the ground detecting circuit is simple and may be miniatured.
With reference to
The external grounding port (14) is mounted in the casing (11), connected to the ground blade (123) and corresponding to the opening (112) of the casing (11). When the user adjusts that the power strip having bad or no grounding connection, the user may use an external grounding wire to connect to the external grounding port (14) of the present invention. In a preferred embodiment, the external grounding port (14) has a rectangular metal seat (141) having a thread hole (142) and a screw (143). The screw (143) is screwed into the thread hole (142) of the metal seat (141) to clip the grounding wire in the metal seat (141) securely. Therefore the grounding wire is electronically connected to the ground blade (123) of the AC plug (12). Further the AC plug (12) is inserted into the AC outlet (21), the grounding wire is also electronically connected to the AC outlet (21) to provide the power strip (20) a good grounding connection.
With reference to
Based on foregoing description, the grounding device also provides a good grounding function for the user. The user does not check or fix the grounding connection inside the power strip, and only uses the grounding wire to connect the external grounding port when the grounding device displays the power strap having bas or no grounding connection.
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
