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What is a hold up time?
Hold-up time is the length of time a power supply can operate in regulation after failure of the AC input. The holdup time, usually measured in milliseconds is an indication of the time the supply will maintain an output voltage within the specified range, after a loss of input supply power.
What is power holdup?
Hold up time indicates the length of time a power supply is able to maintain a consistent output voltage at a regular output level, after it is shut down or in a power shortage.
What is hold up time in chromatography?
Gas holdup time (tM) is a basic parameter in isothermal gas chromatography (GC). t R ′ is an important retention parameter for GC theory and applications, reflecting interactions between the solutes and the stationary phase.
What are external capacitors?
An external capacitor, C1, sets the bandwidth of the demodulator. The output of the synchronous demodulator drives the preamp, an instrumentation amplifier buffer that is referenced to + 1.8 V.
What is the hold up time for UPS?
If the system has a battery-based UPS, then the hold-up time needs to be longer than the time it takes for the UPS to detect an AC failure, switch the power source to the battery and reestablish the proper AC voltage output that will feed the power supply. The hold-up time is typically specified for a particular platform.
Why is it important to know power supply hold up time?
The hold up time specification is important to make sure that the power supply will keep working in case of an AC power outage. If the system has no battery-based UPS, then the hold-up time needs to be longer then the maximum expected AC power outage duration.
What’s the hold up time for a medical device?
There are standards that indirectly define hold-up times. This document shows some tests (e.g. voltage dip of 40% of 20 ms duration or voltage interruption of 60 ms duration). For medical devices, the standard IEC 60601-1 applies. See this document for some durations of voltage dips and interrupts.
Is there hold up time requirement for bulk capacitor?
Sure, holdup time requirement is for output holdup. Depending on topology and on configuration (i.e. whether step up or step down), it can be implemented either with the output capacitor or the bulk capacitor. If the flyback converter is Stepdown, then implementation with bulk capacitor is fine.