circuit harness wiring

You sometimes need to drive a white LED from one 1.5V battery. Unfortunately, the forward voltage of a white LED is 3 to 4V. So, you would need a dc/dc converter to drive the LED from one battery. Using the simple circuit in Figure 1, you can drive one white LED or two series-connected green LEDs, using only a few components. The circuit is a voltage-to-current converter, which converts the battery voltage to a current that passes through the LED.

You can adjust this current and, thus, the brightness of the LED, by varying resistor R3. If you turn on switch S1, resistor R2 feeds base current to transistor Q2. Q2 turns on, and its collector current, via R3, turns on Q1. Now, the current through inductor L1 increases. The slope of the increase is a function of the value of L1 and the battery voltage. The current through L1 increases until it reaches a maximum value, which depends on the gain of Q1. Because the value of R3 sets the base current drawn from Q1, Q1s collector current is also limited.

The circuit of the Celsius thermometer in the diagram is based on the well-known Type LM334 from National Semiconductor. This IC is a sensor that provides a current which is directly proportional to the temperature in kelvin (K). Unfortunately, this is a quantity that is not suitable for use in most practical applications. In the circuit, therefore, the sensor is set to 1µA K–1 with P1 and the offset of 273 K removed with P2.

Celsius Thermometer Circuit Diagram

This renders the output voltage of the sensor directly proportional to the temperature in degrees Celsius (° C) and this makes the circuit suitable for a great many applications (since 1K=1° C). Circuit IC2 is arranged as a 2.5 V reference voltage source. The current setting of the sensor is determined by the resistance between the adj(ust) pin and earth. If the earth is made virtual by raising the potential at the adj pin, the zero point can be shifted as desired. Calibration is best done by using a good domestic thermometer as reference.

Start by short-circuiting IC2 and adjusting P1 until the reading of meter M1 shows a current value numerically equal to the ambient temperature plus 273. If, say, the room temperature is 25°C, adjust P1 until the meter reads 298 µA. Then, remove the short-circuit from IC2 and adjust P2 until the meter reads a current whose numerical value is equal to the room temperature, that is, 25µA. The circuit draws a current not exceeding 1 mA, so using two AA size (AM3, MN1500, LR6, SP/HP7) batteries as power source will give a life of a couple of years.

The indication light on the host of cell phone jammer is red.
Operators network solutions business. Mobile infrastructure network devices, systems and solutions; microwave communication systems and solutions; optical networks solutions; IPTV solution; broadband solutions; mobile communications applications and value-added service solutions for design, development, systems integration and sales; communication software development, design and system integration, and the system equipment, the end product engineering, maintenance and consulting business. History of the development of the mobile phone industry. China mobile phone the course of development can be divided into the era of analog phones, the GSM era era and the era of 3G, 2.5G, 3G represents the development trend of Chinas mobile phone. If the customer wants to disguise the use of cell phone jammer .
The era of analog phones, probably from China Mobile Communications Corporation began operations in 1987 900MHz analog mobile phone service date to December 31, 2001, China Mobile Communications Corporation is the complete cessation of analog mobile phone network customers international and domestic roaming services cut-off. After this, the mobile phone by the analog to digital development, including the rapid development of GSM and CDMA digital mobile phone standard worldwide. In the 1980s, the global mobile phone business is growing very fast. The late 1980s, the global use of wireless telephone terminal users, the number of annual growth rate of 40 percent, far more than the same period the annual growth rate of fixed line telephone users.
Macro environmental factors of the mobile phone industry. Political - legal factors. Specifically, some government action restrictive role in the activities of the enterprises, but some government policy guidance and a positive impact on the enterprise. In accordance with Chinas WTO accession commitments, December 11, 2004, China canceled the limitations of geography, equity and the number of foreign-invested commercial enterprises in Chinas retail sector is opened to all. So that the domestic retail market capacity is rapidly expanding, industry, competition is fiercer than ever. Generally speaking, in the case of macroeconomic development, market expansion and increased demand for business development opportunities. Beginning in 2003, Chinas central governments macro-control targets are mainly concentrated in four areas. It is the high performance heat dissipation chip of cell phone jammer .
Gross domestic product (GDP) growth in the number of degrees, the general price level, the urban unemployment rate or the level of employment, the international balance of payments status.