The repair of switch mode power supplies (SMPS) is economically a nice investment for electronics repair stores and for hobbyists. However, in contrast to the old weak frequency transformers and linear power supply troops (PSUs), SMPS are rather complex. Still, due to their weak weight, high efficiency, and being able to deliever stable voltage output, they have became an ubiquitous component in almost each electronic equipment.
I assume that the viewer has only a primary knowledge of electronics. In this video series we will cover SMPSs and ATX pc supplies starting from the basics and going into the information in the repair of such troops. Here we look into the most important components and building blocks of an SMPS, and we cover the block diagram. Understanding the block diagram is highly important, since it provides an simple idea for a technician to narrow down the potential components which are defective in an SMPS unit.
Due to high amounts of heat dissipated and high switching voltages, and frequencies, power supplies are the most frequent source of failure. Thus, although it takes more time and effort to understand the basics of SMPS, in the long turn it pays off to learn about their inner workings and also about their most frequent failure modes.
In this video we cover the power input, filtering scene and rectification portion of an SMPS. I explain the need for inrush actual limiting. Next, the power distribution is explained on the high voltage DC side, where through the two different paths the stand-by and the high power chopping circuits will be fed, driving the transformers.
The main building blocks and how they are tied together in a modern switch mode power supply:
-power input plug or cable for mains voltage
-input security (fuse, metal oxide varistor MOV)
-EMI/RFI filter (Xcaps, Ycaps, common mode chokes)
-rectifier diode bridge
-inrush actual rimiting NTC Thermistor
-active or passive power factor correction (PFC) circuit
-bulk mains filter capacitor
-controller circuit for the FET of the stand-by power and main power
-stand-by and main power transformers (high frequency ferrite)
-Schottky diodes for the secondary side rectification
-electrolytic filter caps
-voltage reference circuit
-optocoupler and feedback loop
-over-voltage and over-actual security circuit
Nice video, and awesome approach to breaking the system down to explainable sub-components.
Yes yes yes awesome . Love the part that claims "University pumped our head full of fully useless mathematics " So real...
what accent is this? not England and not US and not India
This was exactly what I was looking for. Supports so much to understand the schematics and identification of parts as a rookie :) Thnx a ton for making the video, liked and subbed.
the finest video about how switch mode power supplies work
Better than silly Universities...
Thanks 4 this !
1:25 haha so real "they pump our heads full with useless equipment" reminds me of my school time, ~85% useless waste of time or even wrong
I have 10 non working Bitmain 1600 watt PSU ,s that I need to repair ( apw3++ model ) after watching this video fully I actually understand a lot more and feel confident to test it ,I have a working unit and some smart tweezers a component analyser ,and a voltage play metre ,hopefully taking readings from working one and comparing I will search broken parts .as there is no circuit diagram from supplier )0; actually subscribed liked etc...
I'm sorry, i can't resist: 10:41, the Borg have arrived!
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