Control circuit for an LED traffic light using a pulse width modulation signal
First Claim
1. A control circuit for traffic light comprising:
- a pulse control circuit, comprising a control chip capable of outputting a low level signal and a pulse-width modulation (PWM) signal by turns, wherein the duration of the low level signal is longer than that of the PWM signal;
a control switch element;
a control drive circuit for receiving the signals output from the control chip and controlling the control switch element, wherein the control drive circuit comprises a drive switch element, the drive switch element comprises;
a first drive switch terminal connected to the control chip;
a second drive switch terminal connected to the control switch element and also connected to a voltage source through a first drive circuit resistor; and
a third drive switch terminal that is grounded;
a power source; and
an LED connecting to the power source via the control switch element;
wherein the switch element is configured to control the power source to supply power to the LED when the signals output from the control chip are high, and not to supply power to the LED when the signals output from the control chip are low.
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Accused Products
Abstract
A control circuit for traffic light includes a pulse control circuit, a control switch element, a control drive circuit, a power source, and an LED. The pulse control circuit includes a control chip is capable of outputting a low level signal and a pulse-width modulation (PWM) signal by turns. The duration of the low level signal is longer than that of the PWM signal. The control drive circuit for receiving the signals output from the control chip and controlling the control switch element. The LED is connected to the power source via the control switch element. The switch element is configured to control the power source to supply power to the LED when the signals output from the control chip are high, and does not supply power to the LED when the signals output from the control chip are low.
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Citations
18 Claims
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1. A control circuit for traffic light comprising:
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a pulse control circuit, comprising a control chip capable of outputting a low level signal and a pulse-width modulation (PWM) signal by turns, wherein the duration of the low level signal is longer than that of the PWM signal; a control switch element; a control drive circuit for receiving the signals output from the control chip and controlling the control switch element, wherein the control drive circuit comprises a drive switch element, the drive switch element comprises; a first drive switch terminal connected to the control chip; a second drive switch terminal connected to the control switch element and also connected to a voltage source through a first drive circuit resistor; and a third drive switch terminal that is grounded; a power source; and an LED connecting to the power source via the control switch element; wherein the switch element is configured to control the power source to supply power to the LED when the signals output from the control chip are high, and not to supply power to the LED when the signals output from the control chip are low. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for controlling a traffic light, the method comprising of:
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providing; a pulse control circuit, comprising a control chip that outputs a low level signal and a pulse-width modulation (PWM) signal by turns, wherein the duration of the low level signal is longer than that of the PWM signal; a control switch element; a control drive circuit receives the signals output from the control chip and controls the control switch element, wherein the control drive circuit comprises a drive switch element, the drive switch element comprises; a first drive switch terminal connected to the control chip; a second drive switch terminal connected to the control switch element and also connected to a voltage source through a first drive circuit resistor; and a third drive switch terminal that is grounded; a power source; and an LED connecting to the power source via the control switch element; wherein the switch element controls the power source that supplies power to the LED when the signals output from the control chip are high, and does not supply power to the LED when the signals output from the control chip are low. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification