SMART METERS ARE EQUIPPED WITH SWITH MODE POWER SUPPLIES, WHICH WREAK HAVOC WITH THE POWER GRID CAUSING AUDIBLE NOISE ON THE LINES AND DIRTY ELECTRICITY THAT RADIATES INTO YOUR HOME THROUGH THE OUTLETS. THE HARMONIC DISTORTION IS A HEALTH HAZARD AND VIOLATES THE STANDARDS OF IEEE-1992. SMART METERS ARE NOT UL APPROVED SO THIS TOO, IS A SERIOUS SAFETY HAZARD ISSUE BECAUSE IT CAUSES OVERHEATING OF APPLIANCES AND DEVICES IN THE HOME. WHY DO YOU THINK SMART METERS ARE BLOWING UP AND CATCHING ON FIRE….sandaura
Switched-mode power supply
Advantages and disadvantages
The main advantage of the switching power supply is greater efficiency because the switching transistor dissipates little power when acting as a switch. Other advantages include smaller size and lighter weight from the elimination of heavy line-frequency transformers, and lower heat generation due to higher efficiency. Disadvantages include greater complexity, the generation of high-amplitude, high-frequency energy that the low-pass filter must block to avoid electromagnetic interference (EMI), a ripple voltage at the switching frequency and the harmonic frequencies thereof.
Very low cost SMPSs may couple electrical switching noise back onto the mains power line, causing interference with A/V equipment connected to the same phase. Non-power-factor-corrected SMPSs also cause harmonic distortion.
Switched-mode power supply http://en.wikipedia.org/wiki/Switched-mode_power_supply
A switched-mode power supply (switching-mode power supply, switch-mode power supply, SMPS, or switcher) is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently. Like other power supplies, an SMPS transfers power from a source, like mains power, to a load, such as a personal computer, while converting voltage and current characteristics. Unlike a linear power supply, the pass transistor of a switching-mode supply continually switches between low-dissipation, full-on and full-off states, and spends very little time in the high dissipation transitions, which minimizes wasted energy. Ideally, a switched-mode power supply dissipates no power. Voltage regulation is achieved by varying the ratio of on-to-off time. In contrast, a linear power supply regulates the output voltage by continually dissipating power in the pass transistor. This higher power conversion efficiency is an important advantage of a switched-mode power supply. Switched-mode power supplies may also be substantially smaller and lighter than a linear supply due to the smaller transformer size and weight.
Switching regulators are used as replacements for linear regulators when higher efficiency, smaller size or lighter weight are required. They are, however, more complicated; their switching currents can cause electrical noise problems if not carefully suppressed, and simple designs may have a poor power factor.
IEEE 519 Current Distortion Limits. (EXCERPTS)
In addition to the increase in harmonic generators and network resonances, electric
systems and loads have become no less, and in some cases even more, sensitive to
harmonics. There are a number of areas of new and continuing concern:
• Computers, computer-controlled machine tools, and various types of digital
controllers are especially susceptible to harmonics, as well as to other types of
interference. (don’t forget smart meters…sandaura)
• Harmonics can cause damaging dielectric heating in underground cables.
• Inductive metering can be adversely affected by harmonics.
• Capacitor bank failures are frequently caused by harmonics.
• Less conservative designs for rotating machines and transformers aggravate
heating problems caused by harmonics.
• Harmonics can be especially troublesome to communication systems.
Today’s harmonics problems may have more serious and widespread consequences
than in the past. System planners and designers should be able to recognize and avoid
or mitigate such problems.
The effects of harmonics are divided into four general categories:
• effects on the power system itself
• effects on consumer load
• effects on communication circuits
• effects on revenue billing
On the power system, harmonic currents are the main culprit, causing equipment overheating and thermal loss-of-life. This may be a concern for motors or transformers. The impact is worse when network resonances amplify harmonic currents. Harmonics may also interfere with relaying and metering to some degree. Harmonics can also cause thyristor firing errors in converter and SVC installations, metering inaccuracies, and false tripping of protective devices. The performance of consumer equipment, such as motor drives and computer power supplies, can be adversely affected by harmonics. In addition, harmonic currents flowing on power lines can induce noise on nearby communication lines. Harmonic voltage distortion may cause equipment insulation stress, particularly in capacitors. When harmonics cause the voltage impressed on the capacitor bank to be distorted, the peak voltage may be high enough to cause a partial discharge, or corona, within the capacitor dielectric. This may eventually result in a short circuit at the edges of the foil and failure of the capacitor bank. High harmonic currents cause fuse blowing in capacitor banks. This results in a loss of reactive power supply to the system which may cause other problems. Harmonic voltage distortion can effect revenue billing by introducing error into kilowatt hour metering systems that rely upon accurate discernment.