Induction protection type safety power socket circuit diagram

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

Photocoupler

In actual life, since the plug of the plug is inadvertently touched to the metal part of the plug, an accident that causes body injury or electric shock occurs. In order to ensure the safety of electricity, we made a gap between the original power plug and the socket. A control circuit can automatically disconnect the internal power supply of the socket when the hand approaches the socket (about 5cm to 6cm), and automatically restores the power connection inside the socket after the person leaves the socket, without any operation, simple and convenient Practical, it can be said that it is a new type of power socket with "fool" security protection. The block diagram of the socket is shown in Figure 1.
$/> Working principle The schematic diagram of the safety power socket is shown in Figure 2. In normal times, the junction FET VT1 is in a zero-bias state, and the resistance between the drain and the source is small. The V+ potential of the non-inverting input terminal of the integrated operational amplifier IC (voltage comparator operating mode) connected to the drain D is also low. . The V-potential of the inverting input terminal is adjusted to be slightly higher than V+ by the potentiometer RP1. Thus, V+V-, the output terminal Vo of the op amp is changed from 0 to 1, VT2 is turned on, and the relay K is immediately sucked, two groups. The moving piece is connected to the normally open point, and the power socket connected to the normally closed point is in the power-off state, and the power indicator LED is off. In this way, even if the human hand touches the metal part of the plug, there is no electric shock. C3 acts to buffer the clutter and accumulate a certain barrier voltage to improve the sensitivity of the relay K when it is pulled. When the plug is inserted and the hand is removed from the socket, the FET does not sense the electrical signal of the human body (or the sensitivity is insufficient), the circuit returns to the normal working state, the relay is released again, and the external power supply and the neutral line connected to the moving piece are again A power outlet that provides a connection to a normally closed contact. Component selection and fabrication FET VT1 selects 3DJ6 or 3DJ7, and the gate G can solder a thin metal piece with an area of â€‹â€‹about 1cm to increase the sensing effect. DC relay K should use two sets of contacts, and the rated load of the contact should be â‰¥220V/3A as well to meet the needs of general electrical appliances. Other component parameters can be found in the figure. In this example, the D-potential of the FET of the FET is about 0.8V, V- is about 1.8V, and the sensing distance (relay K is sucked) is 5cm~6cm. Since the FET is controlled by the width of the conductive channel, it is susceptible to the environment (noise, temperature, etc.). After a capacitor C2 is connected in parallel between the drain and the source, the drain can be made. The pulsating component of the voltage is reduced to increase its stability. In the actual measurement, the V-potentiometer should be carefully adjusted according to the sensing distance (the hand is the source of induction, and the relay K is sucked into the mark) (the position of the sliding end of the potentiometer RP1 is changed), so that the relay K can be stably sucked. It is better not to be too sensitive to produce vibration (about 6cm ~ 7cm). The position of the FET should be kept away from other components as much as possible to avoid or reduce electromagnetic interference. It should be placed on the side or above, and ensure that the relay is reliable when the plug is 5cm~6cm away from the socket. Pull in. When working normally, the current of the whole machine is about 10mA~15mA. </p> </div> </div> <div class="tech-detail-share">  <div class="bdsharebuttonbox"> <a href="#" class ="bds_qzone" data-cmd="qzone" title="Share to QQ space"></a> <a href="#" class="bds_tsina" data-cmd="tsina" title="Share to Sina Wei Bo"></a> <a href="#" class="bds_weixin" data-cmd="weixin" title="Share to WeChat"></a> <span>Share to:</span> </ Div> <script>window._bd_share_config = { "common": { "bdSnsKey": {}, "bdText": "", "bdMini": "1", "bdMiniList": false, "bdPic": "", "bdStyle": "2", "bdSize": "16" }, "share": {} }; with (document) 0[(getElementsByTagName($

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