TDK-Lambda Americas Blog
Can I use a buffer module to provide peak power capability?
Thursday, December 4, 2025
Introduction
Buffer modules are used to support systems during short AC input power losses. These modules contain electrolytic capacitors which are charged when the AC power is present. The stored energy then provides a DC output voltage to the system enabling it to function during an interruption of the AC power.
The buffer module is connected in parallel, across the power supply output or load. See Figure 1.
Figure 1: Connection of the buffer module
Figure 2: Buffer module
The use of DC motors and pumps is becoming more prevalent in manufacturing, particularly with the use of robotic arms. These items often require peak load currents during operation.
This peak demand can be resolved in a number of ways.
- Install a larger, more expensive power supply.
- Put two smaller AC-DC power supplies in parallel.
- Install power supplies that have a peak power capability. See Figure 3.
- Utilize the system buffer module, or modules, to provide the necessary power. See Figure 4.
Figure 3: TDK-Lambda DRB120-24-3 3-phase input power supply with 50% peak power capability
The energy from the buffer module can be used to provide power to the load for a longer period of time. This will also allow a piece of machinery to safely shutdown or store information on the progress of a particular process. See Figure 4.
Time “T” is the power supply’s power capability and time “Tb” is the additional peak power provided by the buffer module.
Figure 4: Buffer module in circuit
TDK-Lambda offers a wide range of power supplies and accessories for DIN rail mount applications, including AC input filters and modules for system redundancy. Contact our knowledgeable technical support for assistance.
Power Guy
