| 摘要 |
<p>A circuit (12) for monitoring and indicating the output level of an energy source (10), such as the voltage level of a battery (10). The circuit includes a triangle wave generator (14), and a comparison circuit (18) for comparing the triangle wave form to the battery output level and generating a comparison signal. A dual color LED set (D1, D2) displays the comparison signal. The diode set (D1, D2) is activated in one color (D2) when the battery signal is greater than the triangle wave form, while the other color diode (D1) is activated when the battery signal is less than the triangle wave form. When the frequency of the triangular wave is two Hertz, the LED set (D1, D2) produced discernable flashes between the first color LED and the second color LED when the battery signal is within the peak-to-peak value. The ratio of the times the LEDs (D1, D2) are activated is a linear representation of the battery voltage between predetermined ''warning'' and ''discharge'' voltages. When the frequency of the triangular wave is thirty Hertz or greater, any flashes produced by the diode set (D1, D2) switching between activated LEDs are not discernable by the human eye, resulting in a mixing of colors when the battery signal is within the peak-to-peak value of the triangle wave form.</p> |
