- Disassembly Overview
- Electrostatic Discharge (ESD)
- EMI (Electromagnetic Interference)
- Disassembly
- Tools
- Opening the Case
- Cables and Connectors
- Storage Devices
- Motherboards
- Mobile Device Issues
- Reassembly
- Preventive Maintenance
- Basic Electronics Overview
- Electronics Terms
- Power Supply Overview
- Power Supply Form Factors
- Purposes of a Power Supply
- Power Supply Voltages
- Mobile Device Travel and Storage
- Mobile Device Power
- ACPI (Advanced Configuration and Power Interface)
- Replacing or Upgrading a Power Supply
- Symptoms of Power Supply Problems
- Solving Power Supply Problems
- Adverse Power Conditions
- Adverse Power Protection
- Surge Protectors
- Line Conditioners
- Uninterruptible Power Supply (UPS)
- Standby Power Supply (SPS)
- Phone Line Isolator
- Electrical Fires
- Computer Disposal/Recycling
- Soft Skills?Written Communications Skills
- Chapter Summary
- Key Terms
- Review Questions
- Exercises
- Activities
Standby Power Supply (SPS)
A device similar to a UPS is an SPS (standby power supply). An SPS contains a battery like the UPS, but the battery provides power to the computer only when it loses AC power. It does not provide constant power, like the UPS. An SPS is not as effective as a UPS because the SPS must detect a power-out condition first and then switch over to the battery to supply power to the computer. As a result, SPS switching time is important. Any time under 5 milliseconds is fine for most systems. Figures 4.35 and 4.36 show the differences between how SPSs and UPSs work.
Figure 4.35. SPS/line interactive UPS operation
Figure 4.36. Online UPS operation