Difference between revisions of "Switchers"
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| − | + | These things are everywhere. Sometimes called the unfortunate name of wall warts, but better called a DC Power Brick, or AC/DC adapter. | |
| + | ==Basic Operation== | ||
| + | A good (practical) introduction is in Learn Electronics Repair 16, LED Disco Lights. https://www.youtube.com/watch?v=XgPZ1XpVppE | ||
| + | But of course, you can refer to Art of Electronics or Practical Electronics for Beginners. Of course, the problem is that the latter two will tell you the schematic view of operation, whereas LER will show you it on an actual circuit board... | ||
| − | + | This comes down to: Knowing the schematic view and the circuit board view are different disciplines, and they both must be understood. I.e. drawing a schematic is different from layout, but you must have ability in both fields. | |
| − | + | ===Inductorless Switching / Charge Pump converters=== | |
| + | AoE3 9.6.3. Useful for <100mA of current. These are integrated into other ICs at times (covered in AoE). | ||
| − | These | + | ==Calculators== |
| + | <gallery> | ||
| + | File:Switcher calculators.PNG|TI's LM63460 | ||
| + | </gallery> | ||
| + | Some manufacturers will have calculators in addition to the app notes that you can use. | ||
| + | These are often based on excel/spreadsheet software. Reference: https://www.eevblog.com/forum/projects/buck-loop-stability-tuning/msg5453216/?topicseen#msg5453216 As with any spreadsheet per B. Pease (For reference, see his columns https://archive.org/details/Bob_Pease_Lab_Notes), you can only trust it if, and only if, it doesn't have any mistakes in the formulas it's built with... | ||
==Tips/Techniques== | ==Tips/Techniques== | ||
===Stock 5V and 12V=== | ===Stock 5V and 12V=== | ||
| − | These are the most common voltages. Always try to standardize on the most common barrel plug (which is | + | These are the most common voltages. Always try to standardize on the most common barrel plug (which is 2.1mm, and 5.5mm). |
| + | |||
===Diodes Gone Wild=== | ===Diodes Gone Wild=== | ||
| − | He has a number of videos that diagnose broken switching power supplies and is reasonably knowledgeable about them. | + | He has a number of videos that diagnose broken switching power supplies and is reasonably knowledgeable about them. For example, he was able to find a faulty transformer (something that the average repair fellow would not necessarily find), showing in depth knowledge of transformer construction. |
| + | |||
===Example of 5V 8-pin DIP Regulator=== | ===Example of 5V 8-pin DIP Regulator=== | ||
https://www.eevblog.com/forum/repair/need-help-to-identify-a-blown-chip-in-skynet-for-z12c-switching-power-supply/msg5445107/ | https://www.eevblog.com/forum/repair/need-help-to-identify-a-blown-chip-in-skynet-for-z12c-switching-power-supply/msg5445107/ | ||
It's always easy to spot the capacitor and diode. | It's always easy to spot the capacitor and diode. | ||
| + | |||
| + | |||
| + | [[Category:online notes]] | ||
Latest revision as of 08:20, 10 November 2024
These things are everywhere. Sometimes called the unfortunate name of wall warts, but better called a DC Power Brick, or AC/DC adapter.
Basic Operation
A good (practical) introduction is in Learn Electronics Repair 16, LED Disco Lights. https://www.youtube.com/watch?v=XgPZ1XpVppE But of course, you can refer to Art of Electronics or Practical Electronics for Beginners. Of course, the problem is that the latter two will tell you the schematic view of operation, whereas LER will show you it on an actual circuit board...
This comes down to: Knowing the schematic view and the circuit board view are different disciplines, and they both must be understood. I.e. drawing a schematic is different from layout, but you must have ability in both fields.
Inductorless Switching / Charge Pump converters
AoE3 9.6.3. Useful for <100mA of current. These are integrated into other ICs at times (covered in AoE).
Calculators
TI's LM63460
Some manufacturers will have calculators in addition to the app notes that you can use. These are often based on excel/spreadsheet software. Reference: https://www.eevblog.com/forum/projects/buck-loop-stability-tuning/msg5453216/?topicseen#msg5453216 As with any spreadsheet per B. Pease (For reference, see his columns https://archive.org/details/Bob_Pease_Lab_Notes), you can only trust it if, and only if, it doesn't have any mistakes in the formulas it's built with...
Tips/Techniques
Stock 5V and 12V
These are the most common voltages. Always try to standardize on the most common barrel plug (which is 2.1mm, and 5.5mm).
Diodes Gone Wild
He has a number of videos that diagnose broken switching power supplies and is reasonably knowledgeable about them. For example, he was able to find a faulty transformer (something that the average repair fellow would not necessarily find), showing in depth knowledge of transformer construction.
Example of 5V 8-pin DIP Regulator
https://www.eevblog.com/forum/repair/need-help-to-identify-a-blown-chip-in-skynet-for-z12c-switching-power-supply/msg5445107/ It's always easy to spot the capacitor and diode.
