VOLTAGE DETECTING CIRCUIT

• US 20090303063A1
• Filed: 08/21/2008
• Published: 12/10/2009
• Est. Priority Date: 06/06/2008
• Status: Active Grant

• Current Assignee: Primax Electronics Limited
• Original Assignee: Primax Electronics Limited
• Inventors: Su, Chun-Nan, Lai, Chin-Lung
• Granted Patent: US 8,094,032 B2
• Time in Patent Office: Days
• US Class Current: 340/660
• CPC Class Codes: G01R 19/0084 measuring voltage only all subgroups of G01R19/00 take precedence

Abstract

The present invention relates to a voltage detecting circuit for detecting a voltage range of a power source. The voltage detecting circuit includes a micro controlling unit, a boost circuit and a plurality of divider resistors. The micro controlling unit includes a general input/output port and a controlling input/output port. The boost circuit provides a constant voltage. A judgment voltage is obtained according to the divider resistors, the constant voltage and a voltage of the power source. A digital level signal is issued by the general input/output port according to the judgment voltage. In response to the digital level signal, the micro controlling unit generates a corresponding prompt associated with the voltage status of the power source.

Claims

1. A voltage detecting circuit for detecting a voltage range of a power source, said voltage detecting circuit comprising:

a micro controlling unit comprising a general input/output port for issuing a digital level signal to said micro controlling unit and a controlling input/output port for outputting a constant voltage; and

a boost circuit electrically connected to said power source and said micro controlling unit for providing said constant voltage to said micro controlling unit;

a first divider resistor electrically connected to said micro controlling unit, said power source and said boost circuit; and

a second divider resistor connected to said first divider resistor in series and electrically connected to said controlling input/output port of said micro controlling unit, wherein a judgment voltage is obtained according to said first divider resistor, said second divider resistor, said constant voltage and a voltage of said power source, said digital level signal is issued by said general input/output port according to said judgment voltage, said voltage range of said power source is determined by said micro controlling unit according to a logic-level of said digital level signal, and an enabling signal is generated by said micro controlling unit in response to said digital level signal.

2. The voltage detecting circuit according to claim 1 wherein said micro controlling unit generates a first enabling signal if said digital level signal is in a high logic-level state, and said micro controlling unit generates a second enabling signal if said digital level signal is in a low logic-level state.

3. The voltage detecting circuit according to claim 2 wherein said micro controlling unit is further electrically connected to an electronic lighting element, and said electronic lighting element emits a light beam in response to said enable signal.

4. The voltage detecting circuit according to claim 3 wherein said electronic lighting element emits a green light beam in response to said first enable signal, and said electronic lighting element emits a green flashing light beam in response to said second enable signal.

5. The voltage detecting circuit according to claim 3 wherein said electronic lighting element is a light emitting diode or a laser diode.

6. The voltage detecting circuit according to claim 1 wherein said voltage detecting circuit further comprises a third divider resistor, which is connected to said first divider resistor in series and electrically connected to another controlling input/output port of said micro controlling unit, wherein another judgment voltage is obtained according to said first divider resistor, said third divider resistor, said constant voltage and a voltage of said power source and transmitted to said general input/output port.

7. The voltage detecting circuit according to claim 6 wherein another digital level signal is issued by said general input/output port according to said another judgment voltage, and said voltage range of said power source is determined by said micro controlling unit according to said logic-level of said another digital level signal.

8. The voltage detecting circuit according to claim 7 wherein said micro controlling unit generates a first enabling signal if said digital level signal is in a high logic-level state and said another is in a high logic-level state, said micro controlling unit generates a second enabling signal if said digital level signal is in a high logic-level state and said another digital level signal is in a low logic-level state, and said micro controlling unit generates a third enabling signal if said digital level signal is in a low logic-level state and said another digital level signal is in a low logic-level state.

9. The voltage detecting circuit according to claim 8 wherein said micro controlling unit is further electrically connected to an electronic lighting assembly comprising a first electronic lighting element and a second electronic lighting element to emit light beams in response to said first, second and third enable signals, wherein said first electronic lighting element emits a green light beam or a green flashing light beam, and said second electronic lighting element emits a red light beam or a red flashing light beam.

10. The voltage detecting circuit according to claim 9 wherein said first electronic lighting element emits a green light beam in response to said first enable signal, said first electronic lighting element emits a green flashing light beam in response to said second enable signal, and said electronic lighting element emits a red light beam in response to said third enable signal.

11. The voltage detecting circuit according to claim 9 wherein said first electronic lighting element and said second electronic lighting element are light emitting diodes or laser diodes.

12. The voltage detecting circuit according to claim 1 wherein said power source is a battery.

13. The voltage detecting circuit according to claim 1 wherein said boost circuit is a DC to DC converter.