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With the rapid development of new consumer products, we can be sure that homeowners will continue to purchase other devices, such as home entertainment systems and wired or wireless network devices, which will also waste standby and no-load power.

It is estimated that the amount of carbon dioxide emitted during power production accounts for about 40% of all CO2 emissions. Therefore, if electricity demand can be reduced, significant progress can be made in reducing global warming and promoting environmental protection. New research has pointed out that the power waste in private homes is very large, even before the check-in. At the same time, equipment designers are facing the pressure to adopt new ways to design more energy-efficient products, and some of the pressure comes from legislation.

Heating, air conditioning, lighting, cooking and cooling were once considered to be the “big energy consumers” in private homes, and they have received much attention. Subsequent regulations began to shift the focus to environmental temperature control and building and insulation standards for hot water systems, particularly those built under the Energy Star and other energy-saving and green building standards. However, the source of energy waste is more than that, and there are more.

The most dangerous power consumables are often neglected products that appear to be off, but in fact, they continue to consume power when they are idle in standby. Chargers (walls), DVD players, set-top boxes, and televisions are among these products. It should be reiterated that since the focus of government legislation and programs in recent years has been on setting maximum no-load and standby power constraints, engineers designing such products must seek new solutions to meet these regulatory requirements.

In order to clarify the true nature of the various sources of power consumption in private homes, the agency is conducting several new studies, one of which is Lawrence Berkeley NATIONAL, California. Laboratory Berkeley), the study focused on electrical equipment in thirteen new homes in California that have not yet been occupied.

In this study, all household appliances installed by the builders were field tested in both work and standby modes. The results show that the average power consumption of these new homes is 800 kWh/year, and the power consumption of equipment in low-power mode accounts for about half. The average low power consumption (about 440 kWh/year) translates to approximately 50 watts of continuous standby power, which is still in the absence of anyone! At the same time, it should be noted that there are several appliances whose standby power consumption is much higher than expected: gas fireplace, 5 watts; structured wiring board/power supply video camera and a broadband router, 20 watts; garage door opener, 5.4 watts.


Digital TV Adapters (DTAs) are a classic example of the interaction between new technologies and government regulations. By February 2009, US homes that do not have cable or satellite TV will require approximately 30 million digital TV adapters. At present, "Energy Star" is working on the development of relevant specifications, requiring power consumption in sleep mode to be no more than 1 watt, and forced into automatic power-off mode when it is inactive for several hours.

As the public awareness of global warming is increasing, regulatory agencies around the world are also improving more stringent energy-saving standards and regulations. Moreover, certification bodies have begun to turn their attention to global uniform standards development, and are no longer limited to the patchwork of existing standards in individual regions and countries. The most prominent example is the standard for external power supplies (EPS): many certification bodies including the European Commission, CECP (China Energy Conservation Product Certification Center), Australia GREEN Office and KEMCO (Korea Energy Management Company) are planning to adopt and Stars are the same standard as the California Energy Commission (CEC). Finally, some institutions began to shift from the initial requirements to voluntary compliance with relevant standards to enforce relevant standards. In the United States, many states have followed the California Energy Commission and have implemented mandatory requirements.

In addition, the external power supply specification also shows another important direction of regulation. In addition to requiring a low power adapter with a maximum no-load power consumption of 0.5 watts, the EPS specification also requires an average minimum load mode efficiency over a wide load range, as shown in Table 1 below.

Table 1: Energy Star / CEC External Power Supply Efficiency Specifications



For power designers, these new requirements mean that design practices that have been recognized have become unacceptable in terms of no-load power, standby power, and overall power efficiency. In the new regulatory environment, designers must abandon old design practices and adopt new technologies to meet these more demanding requirements.

Achieving such great improvements in energy efficiency is indeed a formidable challenge. However, the good news is always unexpected. In recent years, significant progress has been made in integrated circuit technology. Power supplies designed using these technologies can continue to operate efficiently in the operating power range. Power consumption in standby mode is extremely low and will not Bring additional costs.

Not long ago, many power supplies (both built-in and external) used linear power-frequency transformers with linear regulators. This traditional method is almost impossible to achieve more than 50% of the power, power waste always exists, even under no-load conditions. Not only that, because the price of copper has risen in recent years, the cost advantage of linear power supplies has been lost. As a result, almost all new power supplies today are designed using switching technology.

POWER Integrations is one of the manufacturers of power conversion ICs. In 1998, the company introduced its EcoSmart technology. The switching power supply designed with this technology can work with higher efficiency under standby and no-load conditions. By integrating, the power supply no longer requires any external components, which not only reduces system cost, but also greatly increases reliability. In an IC designed with POWER Integrations' EcoSmart technology, a circuit is integrated on the chip that detects that the power supply is in a low power state (no load or standby). The device then takes one or more steps to increase the efficiency of the power supply in this state. It reduces the "duty cycle" by limiting the supply of power to the load and absorbing less current. Second, it performs a "cycle hopping" and waits for the device to "wake up", thus using power only for a short period of time. This not only can effectively reduce the average operating frequency of the power supply, reduce switching losses, but also improve efficiency under low power conditions.

Figure 1 shows a power supply designed with a TinySwitch-III regulator to illustrate the power of a new power conversion chip. With a bias winding and only three external components, the circuit standby consumption can be drastically reduced from 300mW to 30mW. Therefore, you can save 27 cents in energy costs per year by paying only 1 cent for additional component costs. Figure 2 shows that this design achieves an amazingly consistent efficiency performance across the entire power operating range, in line with current trends in energy efficiency regulations.



Figure 1: No-load power consumption below 30mW with bias winding.



Figure 2: Productivity in different load modes.

The goal that has been proposed is to achieve “zero power consumption” in residential buildings, which can meet the demand for power reduction through solar photovoltaic power generation. Although smart building design has greatly improved power consumption, due to the growth of other power consumption, such as door openers, surveillance cameras and other products that generate energy, reducing power consumption still faces a long road of exploration. Therefore, high-efficiency switching power supply is the inevitable choice for all electronic equipment designers. By replacing the power-consuming linear power supply with a switching power supply, engineers can design products that easily comply with new energy-saving regulations.