发明名称 |
Photosensor circuits including a switch mode power converter |
摘要 |
<p>Photosensor circuits include a relay coil configured to control application of an alternating current (AC) power source to a load. The circuit includes a pulse width modulator circuit configured to generate a pulse width modulated signal having a pulse width that varies responsive to an average voltage across the relay coil. A drive transistor is coupled between the relay coil and a neutral bus that controls the average voltage across the relay coil responsive to the pulse width modulated signal. A photo control circuit is configured to control application of the pulse width modulated signal to the drive transistor responsive to a detected light level. A power circuit includes a half-wave rectifier coupled to the power source that is configured to provide a power signal to the pulse width modulator circuit and a regulated power signal to the photo control circuit. The power signal is a square wave and the power circuit further includes a rectifier circuit and a voltage divider circuit configured to generate the regulated power signal from the power signal. The photo control circuit includes a phototransistor. The phototransistor has a first terminal coupled to the regulated power signal through a first resistor and a second terminal that outputs a current responsive to a level of light detected by the phototransistor. A low pass filter circuit is coupled to the first terminal of the phototransistor that filters the output current of the phototransistor to provide a light level signal voltage and a select transistor couples the pulse width modulated signal to the drive transistor responsive to the light level signal voltage having a selected level.</p> |
申请公布号 |
AU2009308125(B2) |
申请公布日期 |
2015.06.25 |
申请号 |
AU20090308125 |
申请日期 |
2009.10.15 |
申请人 |
TYCO ELECTRONICS CORPORATION |
发明人 |
FLAHERTY, RICHARD CHARLES |
分类号 |
H01L31/00;H05B37/02 |
主分类号 |
H01L31/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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