For this first post we try to learn to know what is SMPS. The easiest term in describing SMPS (Switch Mode Power Supply) is a tool designed for alternative Power Supply. So far we often see the iron transformator as the main component of a conventional power supply.
Understanding SMPS
For understanding SMPS has 2 sense that is:
1. Power Supply is a device used to produce or provide a suitable and stable power source in a particular equipment. And usually the available voltage is alternating voltage 220v or can be called with AC, but an electronics equipment requires DC voltage or direction.
2. Switching Regulator which is an electronic circuit used to stabilize the outgoing voltage, such as the outgoing voltage is not optimal, the load current is less than optimal and other
How SMPS Works :
~ Submission - change AC input voltage to DC output voltage.
~ Converter - converts DC voltage to output voltage according to need.
~ Filtering - removes the pulse at the output voltage.
~ Regulation - makes the output voltage stable to the input voltage changes and load changes.
~ Isolation - Isolate the secondary part of the primary part, with the aim that the chassis of the secondary part if held does not arise the danger of electric shock.
~ Protection - able to protect equipment from over-voltage output and protect power supply from damage in case of error.
The basic parts of SMPS work are as follows:
~ Parts Rectifier. Here the input voltage of 220V AC power is rectified to DC voltage using a diode bridge and 3 large elco filter that is an elco 480V680UF and 2 elco 250V2200UF.
~ Part of enumerator or power-switching. The DC input voltage is enumerated using "on-off power switch" to produce high-frequency pulses of dc pulses. SMPS Inverter welding machines generally work at frequencies from 50Hz to 60Hz. As a power switch can use IC K2611, IRFZ24N and IRF9Z24N.
~ SMPS Controller driver as PWM (Pulse Wave Modulation) pulse generator. As the drive signal for the enumerator used PC 817 IC containing oscillator circuit and PWM as a generator of PWM pulses. There is a SMPS circuit that does not use the SMPS controller driver, in which case a power switching transistor is made to work by "oscillating itself".
~ Switching transformer. The dc voltage that has been chopped has characteristics such as ac voltage so it can be passed by a transformer or inductor to be raised or lowered voltage.
~ The rectification and filtering of the output voltage. The output voltage of the transformer is still a high frequency pulse and then converted to DC voltage using rectifier diode and elco filter.
~ Loop feedback to make the output voltage stable. The feedback loop circuit from the output voltage B + to the primary is used to control the PWM.
~ Comparator circuit as "error detector". A comparator circuit on the secondary part is used to detect if there is a change in the output voltage B +. The comparator works by comparing the output voltage B + with a "reference" voltage (usually a zener diode voltage of 6.8v). The comparator output is a current which is then fed back to the primary through a photo coupler. The coupling using a photocouler aims to isolate the ground of the primary part of the electric shock when held (HOT chassis) with the secondary ground (COLD chasis).
Dimensions and weights.
The ancient powerhouses, especially the most powerful ones, always have large dimensions and heavy weights (capacity determines dimensions and weights), the working frequency is the same as the 50-60 Hz power grid. Whereas SMPS uses much higher working frequency at 50 kHz - 500 kHz. The higher the frequency means the more efficient it works, so it requires a power transformer that is smaller, lighter weight. Thus the size of equipment that uses SMPS as its resources must be more compact size.
Efficiency, Voltage and Output Flow.
The output voltage of the conventional supply depends on the tap on the power transformer. For unregulated types, the output voltage varies depending on the load current. While that is being circulated, the process causes the power dissipation of the transistor (in the form of heat) to decrease the usability, as well as the core conductor losses and the iron core kern is very large, which ultimately all that can produce efficiency only 30-40% only.
At SMPS the voltage is easily set at any voltage and at any current according to the installed capacity without much effect on the dimensions and weights. In SMPS enforcement techniques, regulation is obtained only by adjusting the pulse width, and since the transistor is working completely or completely alive, the heat (and loss of power) is minimal. The disadvantage caused by the capacitor depends only on ESR (equivalent series resistance), so its value is relatively small. Loss of the ferrite core, core conductor and drop-voltage resistor diode. All the so-called contributors are major losers, but with all the losses it can produce a typical efficiency of 60-80%. By improving circuit design, losses can still be minimized, until 95% efficiency is not impossible to achieve.
Efficiency, Voltage and Output Flow.
The output voltage of the conventional supply depends on the tap on the power transformer. For unregulated types, the output voltage varies depending on the load current. While that is being circulated, the process causes the power dissipation of the transistor (in the form of heat) to decrease the usability, as well as the core conductor losses and the iron core kern is very large, which ultimately all that can produce efficiency only 30-40% only.
At SMPS the voltage is easily set at any voltage and at any current according to the installed capacity without much effect on the dimensions and weights. In SMPS enforcement techniques, regulation is obtained only by adjusting the pulse width, and since the transistor is working completely or completely alive, the heat (and loss of power) is minimal. The disadvantage caused by the capacitor depends only on ESR (equivalent series resistance), so its value is relatively small. Loss of the ferrite core, core conductor and drop-voltage resistor diode. All the so-called contributors are major losers, but with all the losses it can produce a typical efficiency of 60-80%. By improving circuit design, losses can still be minimized, until 95% efficiency is not impossible to achieve.