发明名称 |
Fixed frequency, variable duty cycle, square wave dimmer for high intensity gaseous discharge lamp |
摘要 |
A dimmer circuit for an HID lamp is provided for supplying a square wave current therethrough at a constant frequency, but whose duty cycle is variable dependent on a sensed current level. The circuit employs a first pair of transistor switches for reversing polarity through the lamp at a low frequency rate. Associated with each of those transistors is a circuit having a transistor switch connected to a drive circuit employing a timer network. The timer network produces an output that is a square wave, the leading edge of which occurs at regular intervals at a high frequency rate. The trailing edge occurs dependent on a dim/bright voltage setting and upon the amount of current through a sensing resistor in series with the lamp.
|
申请公布号 |
US4170747(A) |
申请公布日期 |
1979.10.09 |
申请号 |
US19780944730 |
申请日期 |
1978.09.22 |
申请人 |
ESQUIRE, INC. |
发明人 |
HOLMES, KENNETH P |
分类号 |
H05B41/288;H05B41/392;(IPC1-7):H05B41/38;G05F1/08 |
主分类号 |
H05B41/288 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|