Isolation tuner
Technical Field
The utility model belongs to the technical field of the TV, especially, relate to an keep apart tuner.
Background
At present, the possession rate of the televisions in the world is very high, and some safety accidents also occur in use, for example, the accidents that the televisions are on fire every year to cause economic loss to users occur, and in some cases, even the casualties of the users are caused. When a television is in a protection mode, the possibility of unbalance exists between a protection grounding wire of a power supply system of a user television and the grounding of a cable television signal network, but a plurality of cable television signal user boxes are not provided with grounding wire isolation at present, so that a television signal input plug (an antenna plug) is directly connected with the grounding of a signal source (the cable television network), and is connected with the protection grounding of the power supply system after being inserted into the television, so that larger current can flow between the two grounding wires to cause overheating of the wires, and further fire disasters are caused. Such accidents occur in China, and cause great damage to lives and properties of users.
In view of this situation, the national standards committee is preparing to issue relevant standards for isolating the ground line of the cable television receiver from the ground line of the tuner signal input terminal as a requirement of mandatory safety regulations.
At present, some television manufacturers use common lead capacitors as isolators, the structures of which are not reasonable, and the distributed inductances are large, so that impedance mismatch is serious, and signals are greatly damaged. Moreover, the isolator causes the structure of the input end to be complex, difficult to process, high in cost and much in material waste.
Therefore, there is a need for an isolation tuner having a good ground isolation effect from the ground of the tv set to meet the practical requirements.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide an keep apart tuner aims at solving the problem that tuner ground wire and TV set ground wire keep apart.
The utility model discloses a realize like this, an keep apart tuner, including the tuner, keep apart the tuner and still include annular noninductive condenser, the ring electrode of annular noninductive condenser one side is connected tuner signal input part's ground wire, the inside ground wire of TV set is connected to the ring electrode of another side.
And a compression elastic pad is arranged between the annular electrode on one surface of the annular non-inductive capacitor and the ground wire of the signal input end.
The compression joint elastic pad is provided with salient points.
The ground wire of the signal input end is matched with the fixed base through a fastening nut, and the pressing elastic pad of the pressing pad on the annular electrode of the annular non-inductive capacitor is in contact with the annular electrode of the annular non-inductive capacitor.
The fixed base is made of an insulating material and is riveted on the shielding cover of the tuner.
The ground wire in the television is connected with the shielding case.
And a compression elastic pad is arranged between the annular electrode on the other side of the annular noninductive capacitor and the ground wire in the television.
The utility model overcomes the defects of the prior art, the utility model provides an isolation tuner, the ground wire of the signal input port of the television tuner is disconnected with the ground wire inside the television, the middle part is coupled with the annular non-inductive capacitor, the isolation of the ground wire of the television and the ground wire of the input signal is realized, the signal reflection caused by the mismatch of transmission impedance caused by adopting the common capacitor to manufacture the isolator is effectively avoided, thereby the signal transmission efficiency is improved, the signal transmission quality is improved, more importantly, the potential safety hazard caused by the non-isolation of the ground wire between the systems is eliminated; furthermore, the utility model provides an keep apart tuner simple structure easily realizes, and is cheaper than doing the isolator in addition in the tuner outside.
Drawings
Fig. 1 is a schematic structural diagram of a signal input terminal of an isolation tuner according to an embodiment of the present invention;
fig. 2 is an exploded view of an isolated tuner signal input assembly according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
As shown in fig. 1 and fig. 2, the signal input terminal of the isolation tuner according to the embodiment of the present invention includes a core 101, a terminal ground 102, an annular non-inductive capacitor 103, a press-fit spring washer 104, a core fixing sleeve 105, a fixing nut 106, a fixing base 107, and the like. Wherein,
the core 101, which is fixed in the fixed base 107 by an insulated core fixing case 105, has an outward end connected to a cable television signal and an inward end connected to an RF (radio frequency) input terminal of the tuner.
The terminal grounding electrode 102 is a metal conductive barrel body with an external thread structure, and can press the two compression joint elastic cushions 104 and the annular non-inductive capacitor 103 clamped therein by screwing the fastening nut 106 embedded in the fixed base 107. The press-fit elastic pads 104 on both sides of the annular non-inductive capacitor 103 are used to improve the contact between the two electrode rings of the annular non-inductive capacitor 103 and the internal and external grounding electrodes, and therefore, a plurality of protrusions are uniformly distributed on the press-fit elastic pads 104.
A fixed base 107, made of an insulating material, is riveted to a shield 108 on the tuner for fixing the above components to form an integral tuner with an isolation function.
The isolation action is explained below along the signal path.
The core 101 is externally connected to the cable television signal core, internally connected to the tuner RF input, and connected to one pole of the signal. After an external signal (cable television signal) wire is inserted, an external signal ground is connected with a terminal grounding electrode 102, the terminal grounding electrode 102 is connected with a ring electrode of the annular non-inductive capacitor 103 through a conductive crimping elastic pad 104, and the ring electrode on the other side of the annular non-inductive capacitor 103 is connected with an internal ground (a grounding electrode of a television) connected with a tuner shielding cover 108 through another conductive crimping elastic pad 104. Thus, the ground of the cable television signal is communicated with the ground inside the television set through the coupling of the annular non-inductive capacitor 103.
To this end, a complete signal loop is implemented. It should be noted that, in the present embodiment, the ground of the cable television signal is not directly connected to the ground inside the television, but the signal is realized by coupling the ring-shaped non-inductive capacitor 103. That is, the annular non-inductive capacitor 103 in this embodiment functions to connect signals between the two systems and to isolate the two systems.
These devices are fixed in a fixing base 107 made of an insulating material, as shown in fig. 1. The tuner shield 108 in fig. 1 is connected to the ground of the television receiver. Thus, in the signal ground path, the ground of the cable television signal is isolated from the ground of the television receiver by the annular non-inductive capacitor 103, and the signal coupling is realized by the annular non-inductive capacitor 103.
The press spring washer 104 is provided with protrusions for improving uniform contact in the annular direction.
The utility model provides an among the technical scheme, because the coupling of signal passes through annular capacitor and realizes, its impedance match can reach better effect than bridging with ordinary electric capacity. In addition, because the isolating device is directly integrated on the signal input terminal of the tuner, the structure is compact and simple, the coupling of signals is further optimized, and the signal reflection, attenuation and introduced interference are reduced.
The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.