手机来电指示器（英文）,Cellular Phone calling Detector

关键字：手机来电指示器,ne555

Flashes a LED when detecting an incoming call
Powered by one 1.5V cell

由一个1.5V电池供电，检测到来电时LED闪烁

Circuit diagram 电路原理图

Parts:
R1 100K 1/4W Resistor
R2 3K9 1/4W Resistor
R3 1M 1/4W Resistor
C1,C2 100nF 63V Polyester Capacitors
C3 220µF 25V Electrolytic Capacitor
D1 LED Red 10mm. Ultra-bright (see Notes)
D2 1N5819 40V 1A Schottky-barrier Diode (see Notes)
Q1 BC547 45V 100mA NPN Transistor
IC1 NE555 or 7555 or TS555CN CMos Timer IC  定时器芯片
L1 Sensor coil (see Notes)
B1 1.5V Battery (AA or AAA cell etc.)

Device purpose:
This circuit was designed to detect when a call is incoming in a cellular phone (even when the calling tone of the device is switched-off) by means of a flashing LED.
The device must be placed a few centimeters from the cellular phone, so its sensor coil L1 can detect the field emitted by the phone receiver during an incoming call.

Circuit operation:
The signal detected by the sensor coil is amplified by transistor Q1 and drives the monostable input pin of IC1. The IC's output voltage is doubled by C2 & D2 in order to drive the high-efficiency ultra-bright LED at a suitable peak-voltage.

Notes:
Stand-by current drawing is less than 200µA, therefore a power on/off switch is unnecessary.
Sensitivity of this circuit depends on the sensor coil type.
L1 can be made by winding 130 to 150 turns of 0.2 mm. enameled wire on a 5 cm. diameter former (e.g. a can). Remove the coil from the former and wind it with insulating tape, thus obtaining a stand-alone coil.
A commercial 10mH miniature inductor, usually sold in the form of a tiny rectangular plastic box, can be used satisfactorily but with lower sensitivity.
IC1 must be a CMos type: only these devices can safely operate at 1.5V supply or less.
Any Schottky-barrier type diode can be used in place of the 1N5819: the BAT46 type is a very good choice.

设备用途：
该电路设计用于通过闪烁的LED检测蜂窝电话中的呼叫何时进入（即使设备的呼叫音被关闭）。
该设备必须放置在距离蜂窝电话几厘米的位置，因此其传感器线圈L1可以在来电期间检测到电话接收器发出的场。
电路操作：
传感器线圈检测到的信号由晶体管Q1放大，并驱动IC1的单稳态输入引脚。 IC的输出电压由C2和D2加倍，以便在合适的峰值电压下驱动高效超高亮LED。
笔记：
待机电流消耗小于200μA，因此不需要电源开/关开关。
该电路的灵敏度取决于传感器线圈类型。
L1可以通过缠绕130至150匝0.2mm来制造。漆包线5厘米。直径成形器（例如罐头）。从前者中取出线圈并用绝缘胶带缠绕，从而获得独立线圈。
商用10mH微型电感器通常以微小矩形塑料盒的形式出售，可以令人满意地使用，但灵敏度较低。
IC1必须是CMos类型：只有这些器件可以安全地以1.5V或更低的电源工作。
可以使用任何肖特基势垒型二极管代替1N5819：BAT46型是一个非常好的选择。