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参数资料
| 型号： | 412101 |
| 厂商： | TT electronics Semelab Limited |
| 英文描述： | Visible Light Detector |
| 中文描述： | 可见光检测器 |
| 文件页数： | 8/11页 |
| 文件大小： | 1045K |
| 代理商： | 412101 |
412101
Visible Light Detector
Preliminary Datasheet
REVISION A
This document is the property of Semefab (Scotland) Ltd. And is furnished in
confidence and upon the condition that it is neither copied or released to a third
party without prior consent.
Page 6 of
11
4.0 Application Examples
Refer to the circuit schematic diagrams appended below.
Automatic Night Light
Fig 2: This circuit show the 412101 in an Automatic Night Light . The Lamp current is
switched by a sensitive gate SCR. The Igt (TYP) of the SCR should be less than 10uA. When
the light is above threshold, current flows between the Vdd and Vss pins of the ASIC which
diverts current away from the gate of the SCR. The light switching threshold can be adjusted
by choosing different values for R2 and R3.
LED Drivers
Fig 3 is a very simple low cost circuit using the 412101 to switch an LED. As the light
increases, current flows between the Vdd and Vss pins of the ASIC which pulls down the
base of TR1. In dark conditions R1 supplies current to the base of TR1 to switch on the LED.
The base current of TR1 must be small compared to the photo current. This circuit should
only be used when the current in the LED is less than 10mA. The DC current gain (hfe) of
TR1 should be > 400 to minimise the base current. The BC550C or equivalent is a suitable
transistor for TR1. This circuit is not suitable for VDC < 4V because of the headroom required
for the LED and TR1. R1 should be adjusted by customers to obtain the switching threshold
to suit the application. This circuit does not have a sharp switching threshold. The LED
brightness decreases over a range of about 30 Lux as the ambient light level increases
towards the cut-off point. The LED current will switch off completely when R1 is pulled down
below about 2.5V. The advantage of this circuit is that it has the smallest number of
components.
FIG4 is a general purpose LED driver. The LED switches ON when the light is less than the
switching threshold (Slux). The base current of TR1 will affect the switching threshold. To
minimise this effect the base current into TR1 should be less than 10uA under all conditions
of temperature and supply voltage. When the ambient light >Slux TR1 pulls down R3 and
switches off TR2. For battery operated applications low current drain is important and the
value of R3 should be as high as possible so that when the LED is off the circuit quiescent
current is low. Slux is controlled by R1 and the base emitter voltage of TR1. R2 limits the
base current into TR1 to prevent excess current with high illumination. R4 controls the LED
current .
Fig5 . In this circuit the LED switches ON when the light is above the switching threshold
Slux. The value of R3 in this circuit can be lower than that in 3B because the current in TR1 is
switched off in low light conditions .
Relay Drivers
Fig 6. The relay coil is energised when the light < Slux. The Slux threshold is set by R1 in the
same way as explained in the description for circuit 3C. For battery operated circuits, the hfe
of TR2 should be high to allow a high value for R3. The hfe of TR1 should be high so that a
low base current will be able to pull R3 down.
Example :
VDC = 6V, relay coil resistance = 100R. min hfe of TR2 = 100, min hfe of TR1 = 200
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相关代理商/技术参数 |
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| 412-101243 | 制造商:Power-One 功能描述:RPF5 COVER |
| 412-102A | 制造商:LG Corporation 功能描述:DECK MECH DH-05V |
| 412-106011 | 功能描述:插入式交流适配器 6VDC/100MA 3.5mm M RoHS:否 制造商:Phihong 地区:Universal 安装风格:Wall, Interchangeable Plug 输入电压范围:90 VAC to 264 VAC 输出端数量:1 输出功率额定值:5 W 输出电压（通道 1）:5 V 输出电流（通道 1）:1 A 直流输出连接器:USB Type A 随附/必需的交流插头:Required 商用/医用:Commercial 效率:Level V |
| 412-106021 | 功能描述:插入式交流适配器 6VDC 200MA 3.5MM RoHS:否 制造商:Phihong 地区:Universal 安装风格:Wall, Interchangeable Plug 输入电压范围:90 VAC to 264 VAC 输出端数量:1 输出功率额定值:5 W 输出电压（通道 1）:5 V 输出电流（通道 1）:1 A 直流输出连接器:USB Type A 随附/必需的交流插头:Required 商用/医用:Commercial 效率:Level V |
| 412-106051 | 功能描述:插入式交流适配器 6VDC/500MA 3.5mm M RoHS:否 制造商:Phihong 地区:Universal 安装风格:Wall, Interchangeable Plug 输入电压范围:90 VAC to 264 VAC 输出端数量:1 输出功率额定值:5 W 输出电压（通道 1）:5 V 输出电流（通道 1）:1 A 直流输出连接器:USB Type A 随附/必需的交流插头:Required 商用/医用:Commercial 效率:Level V |
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