Measuring just 1 by 7/8 by 1/2 inches (2.5 by 2.2 by 1.3 cm), a new power supply module is said to shorten the design cycle and eliminate the need to source and inventory multiple power supply components.
With applications growing for low-power, small-size electronic devices, the BPS-2 Series micro-size switching power supplies from Bias Power are designed to give appliance engineers new options. Said to be smaller than other power devices, they provide a one-component solution, with single or dual output, 85 to 265 V AC universal input and purported high reliability.
The key to the series is a patented circuit design. “Based on the patented technology that is employed, we do not need to use EMI circuitry on the input of our supply,” notes Michael Creighton, director of engineering at Buffalo Grove, Illinois, U.S.-based Bias Power. “Additionally, through careful transformer design and overall packaging, we can maintain a small footprint.”
As part of the patented design, the power device begins switching internally when the input bridge is reverse biased. “This reduces the conducted emissions placed back onto the line. We have a proprietary ASIC that manages this process,” Creighton says.
The 2-W power module is also said to efficiently handle the widest possible load variations and has a no-load power consumption of less than 30 mW. “We are power limited by design,” Creighton notes. “We actively adapt to the load variations based on fixed primary peak current and output voltage.” As a result, the circuit maximizes conversion efficiency up to 75 percent and effectively regulates output voltages.
The new series can be used in low-power and standby mode applications in appliances, consumer electronics and control devices, providing power to system clocks, processors, IR remote receivers, membrane keypads, and LED panel lighting. Basic low-power applications include powering remote and networked sensors, power-line carriers, building automation, audio, video, security, AC power adapters, and bias supplies.
Creighton admits that incorporating the power device into appliances will require a few adjustments, but says the results are worth it. “Based on continuous design improvements, a PCB layout must be redesigned, and in many cases, components can be taken out of the power supply portion of the design,” he says. “Some of the benefits of the module include the universal input 85 to 265 V AC 50/60 Hz that can be achieved when used. This reduces the number of power supply variations that need to exist for a global product.”
In one washing machine application, a control used an EMI filter, 120/230 primary switch, linear transformer, and many passives to achieve regulation and filtering. After implementing the BPS-2 module, Creighton says the company was able to reduce the component count by 14 and automatically adapt to domestic and international power grids.
The power modules are “regulatory ready” (UL/EN60950 and EN55022 Class B, FCC Part 15 B) and are said to be well suited for portable and harsh environment applications. Outputs of 8, 14 and 8 and 5 V DC are available.