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Feature Article
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Issue #206 September
2007
Smart Power
An Intelligent Power Supply for Embedded Systems
by Alexander Popov & Jordan Popov
Start | Hardware | Software | Calibration | Voltage Presets | Slowly Rising Voltage | Slowly Falling Voltage | Short Time Test | Periodcal Linear Voltage | Periodical Voltage Drops | Future Development | Sources & PDF
SLOWLY FALLING VOLTAGE
Regardless of the power supply circuit used in an embedded system, when the power turns off, the output filter capacitor discharges through the circuit and the voltage slowly falls (see Photo 4). This is more common than the rising voltage condition during power-on. The effects to the circuit are similar and the measures taken to eliminate the risks during power-on should work here too. Nevertheless, it’s always better to test, not to assume, so this preset will be helpful to see how the circuit behaves after it is switched off.
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| Photo 4—This is a test for the behavior of the circuit after the power supply is switched off. |
The parameters are: T_FALL, the time for falling from default voltage to V_TO, voltage level.
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