Power supply designs have come a long way since the linear power supply was developed. Most power supplies in use today are of the "switching" type rather than the linear type described above. And you can find switching supplies in every computer sold.
Switching power supplies use higher frequency techniques to convert the 110 VAC, 60 Hz power source into clean, reliable DC. Their designs are also far more efficient in terms of converting AC to DC. The big problem lies in how to cancel out all the high frequency components that they generate internally before they become part of the DC ripple output. So while switching power supplies are cheaper, more cost and power efficient, weigh less and come in smaller packages as compared with linear supplies, their big drawback is in their design complexity.
To aid in lessening the burden of designing switching power supplies, many integrated circuit manufacturers have embarked in making ASICs (Application Specific Integrated Circuits), which can be used in all sorts of 'switcher' designs. One particular company, National Semiconductor Corporation has a website dedicated to simple, yet effective, switching power supply designs. A design engineer can log on to their WebBench site at http://www.national.com/appinfo/power/ and design a good switching power supply by just "filling in the blanks" (below).
WEBENCH™ Online Power Supply Design Tools
WEBENCH Online Power Supply Design Tools feature
These tools speed up the design process, improving productivity and time to market.
Enter your power supply design requirements
Ambient Temperature °C
Click here to enter more outputs
Figure 5-34: National Semiconductor's WEBENCH™ Software Images © National Semiconductor; used with permission.
Was this article helpful?