UPS Battery of Time and Attendance Devices

UPS Battery of Time and Attendance Devices

An uninterruptible power supply (UPS) is an electrical apparatus that provides emergency power to a load when the input power source or mains power fails. A UPS differs from an auxiliary or emergency power system or standby generator. It will provide near-instantaneous protection from input power interruptions by supplying energy stored in batteries, supercapacitors, or flywheels.

UPS Components

  • Rectifier: This part of the UPS converts the incoming alternating current (AC) supply to direct current (DC) and can provide charging current for the battery and the inverter's supply requirements.
  • Charger: In several UPS systems, a separate battery charger is used due to its design nature.
  • Battery: This is the power storage section and is kept charged either by the rectifier or a separate charger. Its storage capacity is generally displayed as Ah (ampere-hour), which is the number of current amperes that the battery can supply for an hour.
  • Inverter: This section of the Uninterruptible power supply provides an AC output to the load, which is in phase with the input mains supply. Due to the number of conversions (AC to DC to AC) and the filtering involved, it can be termed a ‘clean supply.’

Types of UPS

  • Offline/standby UPS: An offline/standby UPS offers only the most basic features, providing surge protection and battery backup. The protected equipment is usually connected directly to incoming utility power. When the incoming voltage falls below or rises above a predetermined level, the SPS(Standby Power Supply) turns on its internal DC-AC inverter circuitry, powered by an internal storage battery. The SPS then mechanically switches the connected equipment onto its DC-AC inverter output. The switchover time can be as long as 25 milliseconds depending on the amount of time it takes the standby UPS to detect the lost utility voltage. The UPS will be designed for specific power equipment, such as a personal computer, without any objectionable dip or brownout to that device.
  • Online/double-conversion UPS: An online UPS is ideal for environments where electrical isolation is necessary or equipment sensitive to power fluctuations. The online UPS' initial cost may be higher, but its total cost of ownership is generally lower due to longer battery life. The online UPS may be necessary when the power environment is "noisy," when utility power sags, outages, and other anomalies are frequent when protecting sensitive IT equipment loads is required, or operation from an extended-run backup generator is necessary.
  • Line-interactive UPS: A line-interactive UPS is similar in function to a standby UPS, but with the addition of a multi-tap variable-voltage autotransformer. This is a particular type of transformer that can add or subtract powered coils of wire, thereby increasing or decreasing the magnetic field and the transformer's output voltage. This is also known as a Buck-boost transformer. This type of UPS can tolerate continuous under-voltage brownouts and overvoltage surges without consuming the limited reserve battery power. It instead compensates by automatically selecting different power taps on the autotransformer.

What is UPS Bypass mode?

UPS Bypass mode is when you switch the circuit from going through the UPS to going around or bypassing it. A manual bypass switch is used to remove the UPS system from the circuit for servicing or maintenance or no longer working correctly. An automatic transfer switch functions in the same way as a manual but will automatically switch the UPSs load to mains electric if the UPS experiences an internal failure.

UPS Battery of time and attendance system:

When the time and attendance device is connected to power, the internal UPS battery starts charging. When the main emphasis is cut off, at the same time, the relay automatically allows the internal battery to be used without interruption to maintain the time and attendance device. The charge time duration of a UPS battery lasts from 6 to 8 hours depending on the availability of time and attendance device and between 8 and 20 hours providing the time attendance device until it turns off.

The UPS batteries are used in time and attendance devices:

  • Nickel-cadmium battery 7.4 volt for PF and Timax time and attendance devices version: 2&3
  • Lithium batteries 7.4 volts for Timax time and attendance devices version: 4&5
  • Batteries 11.2 volts for Virdi time and attendance devices

How long are UPS batteries usable when the power has been cut off?

  • Timax fingerprint time and attendance battery provide 26 hours for standby mode and 8 hours for outstanding sensor and device use.
  • The ZK uFace 102 face recognition time and attendance device's battery provides 4 hours for standby mode and 2 hours for outstanding sensor and device use.

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