Tweet
các bạn xem giúp mình sơ đồ mạch điện sau:http://www.kitehost.com/dientuvienth...1%BB%99ng.html
- 30.10.2006 - Báo sóng cho điện thoại di động
Nguồn 1.5V
--------------------------------------------------------------------------------
R1____________100K 1/4W ResistorR2______________3K9 1/4W ResistorR3______________1M 1/4W ResistorC1,C2_________100nF 63V Polyester CapacitorsC3____________220µF 25V Electrolytic CapacitorD1______________LED Red 10mm. Ultra-bright (see Notes)D2___________1N5819 40V 1A Schottky-barrier Diode (see Notes)Q1____________BC547 45V 100mA NPN TransistorIC1____________7555 or TS555CN CMos Timer ICL1_____________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.
.................................................. ...............................................
Mình ko hiểu tại sao để sáng đèn LED (Red) thì cần có điện áp + 1,7 vol trở lên vào đầu + của LED, mà ở đây chỉ dùng nguồn +1,5V? . Mạch này có thể phát hiện sóng dtdd với khoảng cách bao nhiêu?. Hướng dẫn cho mình cách quấn cuộn dây L1 nữa nhé.
- 30.10.2006 - Báo sóng cho điện thoại di động
Nguồn 1.5V
--------------------------------------------------------------------------------
R1____________100K 1/4W ResistorR2______________3K9 1/4W ResistorR3______________1M 1/4W ResistorC1,C2_________100nF 63V Polyester CapacitorsC3____________220µF 25V Electrolytic CapacitorD1______________LED Red 10mm. Ultra-bright (see Notes)D2___________1N5819 40V 1A Schottky-barrier Diode (see Notes)Q1____________BC547 45V 100mA NPN TransistorIC1____________7555 or TS555CN CMos Timer ICL1_____________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.
.................................................. ...............................................
Mình ko hiểu tại sao để sáng đèn LED (Red) thì cần có điện áp + 1,7 vol trở lên vào đầu + của LED, mà ở đây chỉ dùng nguồn +1,5V? . Mạch này có thể phát hiện sóng dtdd với khoảng cách bao nhiêu?. Hướng dẫn cho mình cách quấn cuộn dây L1 nữa nhé.
Attached Files
Comment