The LTM4601 DC/DC μModule regulator is a completehigh power density stepdown regulator for up to 12Acontinuous (14A peak) loads. The device is housed ina small 15mm ¥ 15mm ¥ 2.8mm LGA surface mountpackage, thus the large power dissipation is a challengein some applications. This thermal application note willprovide guidelines for using the μModule regulator inAmbient environments with or without air fl ow. Loadcurrent derating curves are provided for several inputvoltages and output voltages versus Ambient temperatureand air fl ow.
Digitemp Junior – An RS-232 Port-Powered Digital Thermometer
Digitemp Jr. is a device that is designed to measure
and report Ambient temperature. When connected to
an RS-232 port on any PC, it will periodically measure
and report in ASCII form the Ambient temperature in
degrees Celsius. These temperature readings can be
monitored with any terminal program. If the terminal
program supports capture to disk, the temperature
readings can be saved to disk for further analysis with
a spreadsheet program or other data analysis tool. The
simple ASCII output format of Digitemp Jr. makes it rel-
atively easy to write custom software for receiving,
recording, and analyzing Ambient temperature data.
Best of all, Digitemp Jr. requires no external power sup-
plies or batteries. It is powered directly by the RS-232 port.
Digitemp Jr. is a device that is designed to measure
and report Ambient temperature. When connected to
an RS-232 port on any PC, it will periodically measure
and report in ASCII form the Ambient temperature in
degrees Celsius. These temperature readings can be
monitored with any terminal program. If the terminal
program supports capture to disk, the temperature
readings can be saved to disk for further analysis with
a spreadsheet program or other data analysis tool. The
simple ASCII output format of Digitemp Jr. makes it relatively
easy to write custom software for receiving,
recording, and analyzing Ambient temperature data.
Best of all, Digitemp Jr. requires no external power supplies
or batteries. It is powered directly by the RS-232
port.
為滿足礦井安全生產要求，介紹了一種以AT89C51單片機為主控器，對環境空氣的溫度、有毒易燃氣體的濃度等進行檢測的監控系統。該系統配合外圍電路能實現對上述環境指標的控制并存儲相關數據與上位PC機通信。它采用硬件抗干擾和軟件抗干擾技術，以確保整個系統工作的準確性。
Abstract:
In order to meet the needs of mine produce safety，a kind of intellignet mine Ambient monotoring and control system based on AT89C51 is introduced.This system can detect the temperature of Ambient of mine，the density of poisonous inflammable gas,combined external circuit.With its function part， this system can change above-mentioned elements.
Abstract: This application note explains how to design an intelligent lighting controller that senses and measures the Ambient lightlevel with an Ambient light sensor (ALS). Equipped with a real-time clock (RTC), the controller also knows when to turn lighting on oroff at specified times. The system presented in this document can be used to control all luminaires that are mains-supply operated.Controller software is also provided in hex format.
The AZ1117 is a series of low dropout three-terminal regulators with a dropout of 1.15V at 1A output current.
The AZ1117 series provides current limiting and thermal shutdown. Its circuit includes a trimmed bandgap reference to assure output voltage accuracy to be within 1% for 1.5V, 1.8V, 2.5V, 2.85V, 3.3V, 5.0V and adjustable versions or 2% for 1.2V version. Current limit is trimmed to ensure specified output current and controlled short-circuit current. On-chip thermal shutdown provides protection against any combination of overload and Ambient temperature that would create excessive junction temperature.
The AZ1117 has an adjustable version, that can provide the output voltage from 1.25V to 12V with only 2 external resistors.
One traditional view of how wireless networks evolve is of a continuous, inevitable progres-
sion to higher link speeds, combined with greater mobility over wider areas. This standpoint
certainly captures the development from first and second generation cellular systems focused
on voice support, and the early short-range wireless data networks, through to today’s 3G
cellular and mobile broadband systems; there is every confidence that the trend will continue
some way into the future.
The PW4055 is a complete constant-current /constant-voltage linear charger for single cell lithiumion batteries.Its ThinSOT package and low external component count make the PW4055 ideallysuited for portable applications.Furthermore, the PW4055 is specifically designed to work within USBpower specifications.The PW4055 No external sense resistor is needed, and no blocking diode is required due to theinternal MOSFET architecture.Thermal feedback regulates the charge current to limit the dietemperature during high power operation or high Ambient temperature. The charge voltage is fixedat 4.2V, and the charge current can be programmed externally with a single resistor. The PW4055automatically terminates the charge cycle when the charge current drops to 1/10th the programmedvalue after the final float voltage is reached. When the input supply (wall adapter or USB supply) isremoved, the PW4055 automatically enters a low current state, dropping the battery drain currentto less than 2μA. The PW4055 can be put into shutdown mode, reducing the supply current to 25μA.The BAT pin has a 7KV ESD(HBM) capability. Other features include charge current monitor, undervoltage lockout, automatic recharge and a status pin to indicate charge termination and the presenceof an input voltage
