Quantcast THE BASIC POWER SUPPLY

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
3-2 THE BASIC POWER SUPPLY Figure 3-1 shows the block diagram of the basic power supply. Most power supplies are made up of four basic sections: a TRANSFORMER, a RECTIFIER, a FILTER, and a REGULATOR. Figure 3-1.—Block diagram of a basic power supply. As you can see, the first section is the TRANSFORMER. The transformer serves two primary purposes: (1) to step up or step down the input line voltage to the desired level and (2) to couple this voltage to the rectifier section. The RECTIFIER section converts the ac signal to a pulsating dc voltage. However, you will see later in this chapter that the pulsating dc voltage is not desirable. For this reason, a FILTER section is used to convert the pulsating dc voltage to filtered dc voltage. The final section, the REGULATOR, does just what the name implies. It maintains the output of the power supply at a constant level in spite of large changes in load current or in input line voltage. Depending upon the design of the equipment, the output of the regulator will maintain a constant dc voltage within certain limits. Now that you know what each section does, let's trace a signal through the power supply and see what changes are made to the input signal. In figure 3-2, the input signal of 120 volts ac is applied to the primary of the transformer, which has a turns ratio of 1:3. We can calculate the output by multiplying the input voltage by the ratio of turns in the secondary winding to turns in the primary winding. Therefore, the output voltage of our example is: 120 volts ac × 3, or 360 volts ac. Depending on the type of rectifier used (full-wave or half-wave), the output from the rectifier will be a portion of the input. Figure 3-2 shows the ripple waveform associated with a full-wave rectifier. The filter section contains a network of resistors, capacitors, or inductors that controls the rise and fall time of the varying signal so that the signal remains at a more constant dc level. You will see this more clearly in the discussion of the actual filter circuits. You can see that the output of the filter is at a 180-volt dc level with an ac RIPPLE voltage riding on it. (Ripple voltage is a small ac voltage riding at some dc voltage level. Normally, ripple voltage is an unwanted ac voltage created by the filter section of a power supply.) This signal now goes to the regulator where it will be maintained at approximately 180 volts dc to the load. Figure 3-2.—Block diagram of a power supply. Q1.   What are the four basic sections to a power supply? Q2.   What is the purpose of the regulator?


Electrical News
Friday Quiz: Voltage References
Voltage references are basic building blocks for ADCs and DACs,...
eetimes.com
Broadcom Flips on Future Set Tops
Broadcom is nestled between traditional cable companies and newer over...
eetimes.com
GaN Pumps Power Revolution
Gallium nitride is ramping up a revolution in power conversion,...
eetimes.com
Introducing USB Type-C -- USB for 21st Century Systems
Industry leaders are poised to start rolling out devices enabled...
eetimes.com
Chinese Walls and Back Doors
Qualcomm and U.S. industry are the losers as China's antitrust...
eetimes.com
Intel 5th Gen vPro Goes 60GHz Wireless
Intel has incorporated Pro Wireless Display (WiDi) and Wireless Docking...
eetimes.com
Backplanes Hit a Wall at 56G
Backplane-based systems are hitting a wall at 56 Gbit/second speeds,...
eetimes.com
Can Kevlar prevent lithium-ion battery fire risks?
University of Michigan researchers have used nanofibers extracted from Kevlar...
eetimes.com
The Art Of Electronics 3rd Edition is Almost Here!
Massive news! A new edition of the bible is almost...
eevblog.com
Wi-Fi Alliance Radiates Outward
The Wi-Fi Alliance is one of several industry groups grappling...
eetimes.com
Connected Car: Dramatic Growth Ahead
Market research and IT consultant firm Gartner predicts a dramatic...
eetimes.com
What Drove CES 2015 Innovation? IP and IP Subsystems
How do we manage all those blocks in an age...
eetimes.com
What Drove CES 2015 Innovation? IP and IP Subsystems
How do we manage all those blocks in an age...
eetimes.com
The Problem with Big Data
There is a lot of potential in Big Data, but...
eetimes.com
UMC Boosts Capex to Capture More 28nm Orders
UMC's large capex increase to capture more 28nm orders indicates...
eetimes.com
Moore's Law Cover Human Progress
Can a Moore's-like law be applied to anything? Where there...
eetimes.com
Quantum Entanglement Now On-a-Chip
Uncrackable encryption and quantum computers enabled by tiny 20 micron...
eetimes.com
Patent Law's Global Grey Areas
Patent law has unresolved grey areas when it comes to...
eetimes.com
TSVs to Split More Chips: Re-Integration is the Focus
At the 3D TSV summit, the speakers agreed on one...
eetimes.com
Startup Casts a Better IoT Network
Startup IoT Freeway claims it has a better wireless network...
eetimes.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +