When electronic production or electrical repair, electronic components for screening and detection is a very important aspect. Here are a use of flashlight circuit (ie, batteries and electrical beads lamp circuit) as tools to test electronic components, and can easily detect some of the common good or bad quality electronic components, not only simple and practical results were quite good, finishing a few cases here detection methods commonly used electronic components, only for reference. A detecting diode 1N400 ××
Usually the assembly and maintenance of various types of electrical and electronic rectifier power supply, 1N400 ×× diode applications is considerably more. Detecting diode performance using a flashlight circuit, can quickly determine its quality. Let the battery positive diodes on any foot, if small bulb does not light, proof positive of the battery is negative diode; if a faint light bulb, it is positive, but also shows the good performance of the diode. If the battery positive touch diode can either kick the small bulb light, a description of this diode is shorted internally; if the bulb is not lit, the LED interior has been disconnected. Note: This method can not determine the diode voltage.
Second, the detection of light-emitting diodes
Light-emitting diodes for its low voltage, so use a flashlight circuit can intuitively judge its performance and quality is good or bad. If the test light emitting diode emitting diodes across the access circuit is not lit, while access to the circuit again to swap polarity, shimmering light tube, then prove the good performance of the tube, and can determine the luminous tube and battery negative contact pin is the anode, the other foot arc tube is positive. But if not light lit by the above two access circuit diode, it shows that the tube has been bad. But then, as the light emitting tube twice the access circuit, although the LED are not bright, but the circuit already small bulb shining light, then the light-emitting tube has an internal breakdown conduction.
Third, the detection of SCR
Applications can also estimate the flashlight circuit is good or bad situation and turned on and off thyristor tube. K negative electrode of the battery is connected to the SCR, A pole and battery positive phase, when the circuit is small bulb if not bright, then prove that the forward blocking thyristor basic good performance. Find a thin wire to the battery's positive terminal and the control electrode of SCR (G) quickly touch it, then if the flash bulb lights up, then the good performance of the SCR conduction. If the wires touch the bulb does not light, or a small bulb shining moment look again immediately extinguished, then turned on the ability of the tube is poor and can not be turned on.
Fourth, the detection of small power transistor
For the commonly used low-power transistor, the transistor as 9013,9014, etc., can also use the flashlight circuit, quick to judge the quality of a crude measure of its performance. The positive electrode of the battery connected to the transistor circuit of the base, respectively, to touch the battery negative pole collector and emitter of transistor. If the collector in touch bulb that is luminous dark red light, and touch the bulb when the emitter also made bright, it is proved that the basic properties of the tube well. If the touch collector or emitter, only one of which bulb is not lit, it indicates the presence of an electrode disconnection of the tube. But when the battery negative touch the collector and emitter, the bulbs are not light, then prove that the interior of the tube is open.
Ton, and these stocks have been controlled up traders and banks and other institutions, the amount of the LME and COMEX market deliverable may be very limited. Seen in this light, even if the State Reserve on the contract is not CU0412 pick, even parity appeared rational return home and abroad, under the conditions of the global copper market demand, the domestic spot supply situation is also difficult to materially improve in the short term. Therefore, I believe, before the Spring Festival this year, the domestic copper market supply pattern will continue, high backwardation situation will continue, this time squeeze still dominate the domestic copper market trend, the domestic price of copper bull market yet the last time the development of madness. (Zhongzheng Wang)
RMB appreciation on the pros and cons of my electronics manufacturing
RMB appreciation will have on China's electronic information products manufacturing multiple effects, the export of China's electronic information products vulnerable to shocks, business competition will further intensify, but because our country has a good industrial supporting environment, industry cluster scale obviously, our electronic information products manufacturing base is not large-scale relocation.
This year, under the impact of the international economic and political factors, the impact of the expected appreciation of the renminbi against the electronic information industry, foreign trade, more and more obvious: Chibidaigou importers, exporters ahead of supply, import growth far behind export growth, the trade surplus increased. In this context, a rainy day, the electronic information industry research RMB appreciation impact under the conditions established trend, is necessary.
First, export vulnerable imports benefited significantly
From the export point of view, China's electronic information products export low value-added, low price space, making the impact of RMB appreciation easy export of electronic information products. Electronic information industry is one of the largest export volume of China's pillar industries, industrial export dependence up to 62.5%, the RMB appreciation impact on the exports of electronic information products is obvious, currency rises will reduce the already meager profit margins, thereby reducing business export enthusiasm.
Imports from, the demand for imported products of China's electronic information industry elasticity is low, the global energy and materials prices continue to rise, making imports of appreciation will benefit not obvious. China's electronic information products imported mainly in parts of the main purpose is to meet the needs of domestic electronic machine assembly manufacturing. Total imports over one billion US dollars of products include: integrated circuits, printed circuits, transistors, hard drives, optical drives, capacitors, mobile phones, automatic placement machine, color data graphic display tubes, electro-acoustic devices.
In addition to mobile phones imported to meet the needs of high-end consumer, the other imports of electronic information products are designed to meet the needs of machine manufacturing. In the current global supply shortage of raw materials and energy, prices continued upward trend, suppliers increase the price of domestic enterprises increased costs would far exceed the import purchase receipts due to the currency appreciation.
Based on the above analysis, the appreciation of the renminbi, the export of greater impact, while imports benefiting condition is not obvious, the results may lead to a temporary surplus or deficit narrowed situation.
Second, less impact on foreign-funded enterprises, domestic enterprises increased competition, employment will decline
Exchange rate changes will directly affect the economic benefits of export enterprises, China's electronic information products export to foreign-based, foreign-funded enterprises in 2004 exports accounted for 85.8% of all exports, including exports of foreign-owned enterprises accounted for 63.1% of total exports. Foreign strong comprehensive competitiveness make it a higher exchange rate risk resilience.
In contrast, the adverse effects of RMB appreciation is more difficult to circumvent domestic enterprises. 2004, mainly funded enterprises within the statistical complete industry sales profit margin of only 4.1%. Low profit margins, companies lack the price, RMB appreciation would have a negative impact on exports large domestic enterprises.
After the RMB appreciation, external operating conditions change would force companies to competition. Due to domestic enterprises and foreign competitive products generally fall dislocation competition in the short term, Southeast Asia, alternative production in Eastern Europe can also can not have our scale conditions, therefore, the main business competition will focus on providing domestic enterprises of the domestic industry. In the short term, domestic enterprises difficult to achieve the high-tech, high value-added products change, therefore, reduce their costs and increase unit productivity, expand the scale has become the primary means of domestic enterprises to compete.
Third, the manufacturing base will not be shaken, it is possible to enhance industrial competitiveness
On the electronic information industry, despite the appreciation of the renminbi would have a detrimental affect exports, but will not shake China's strategic position as the world's major electronic information products manufacturing base.
Historical experience has proved that the currency appreciation does not mean disaster. After four consecutive Japanese currency appreciation experienced after the Plaza Accord, the domestic electronic information industry is not dead, Toshiba, NEC, Mitsubishi Electric, SONY, Fujitsu and other electronics giant hand will be transferred to the lower value-added manufacturing * **, on the other hand get ahead pricing advantage monopoly profits generated by the core product technology through continuous innovation. Currently, the Japanese home appliance enterprises on behalf of e-business technology leader in gesture again to enter the market. Even so concerned, if the currency appreciation caused by the trade deficit, as long as this trade deficit is due to the high efficiency of the drive caused by high investment, and to lose control, it is not only not a bad thing but a good thing.
Meanwhile, China's electronic information industry already has spent the condition of the currency appreciation shocks. First, a high concentration of industrial clusters within a firm footing and improve the industrial chain, reducing the risk of China's electronic information industry relocation. Second, China's electronic information industry, the industry has grown a number of preliminary international competitiveness of large enterprises. Resources, talents, market share and other factors to the advantage of companies focused on their own conditions conducive to enterprise through exchange rate risk.
In addition, although the currency appreciation will stimulate domestic enterprise competition intensified, resulting in some people lose their jobs, but also the birth of China's electronic information industry upgrading.
