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- CLCLCLC \u2013 last L is a common-mode choke<\/li>\n
- CRCRCLC \u2013 L is a common-mode choke<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
There is a fuse holder on board as well as LED (TH or SMD) indicator.<\/p>\n
It\u2019s your choice to decide what elements of the board you would use. The board may be a bit bigger than expected, however this way you can fit a wide good range of capacitors in it. It feels to me it has a good compromise in terms of flexibility and size.<\/p>\n
Overview<\/h2>\n
The circuit is very straight-forward and well known so I will just reference its parts. You should be knowledgeable on LT supplies and I recommend highly you use PSUD2 software to model and confirm the dynamic response of your supply.<\/p>\n
![\"\"](\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2021\/10\/LT-Supply-PCBv03-scaled.jpg?resize=840%2C271&ssl=1\")
<\/a>LT Supply PCBv03<\/figcaption><\/figure>\n <\/div>\nThe circuit can be broken down in the following parts:<\/p>\n
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- Input snubber circuit is R2 and C1. Typical values shown on the diagram below.<\/li>\n
- Rectifier diode bridge D1 to D14 in either DO-41 (D5-D8), TO-220 (D1-D4) or SOD-128 (D11-D14). Please place only 4 rectifier (obvious but worth mentioning).<\/li>\n
- C2 is the voltage \u201ctunning\u201d capacitor. Preferable Polymer Aluminum type. Make sure ESR and ripple current matches your needs.<\/li>\n
- R1 and R3 (3 to 5W size) used as part of first RC and\/or ripple current dampening and protection of the C3 capacitor. When L2 is used, R1 is omitted and R3 generally replaced with a simple wire.<\/li>\n
- L2 and L3 external chokes connected via a 2mm bullet connector. You can solder straight wires to the board if preferred.<\/li>\n
- R4 (3 to 5W size) works in same way as R1.<\/li>\n
- C3, C4 and C5 are electrolytic SNAP-IN type capacitors. Make sure ESR and ripple current matches your needs.<\/li>\n
- L1 is a common mode choke. There are 3 mounting case \/ lead spacing options to fit multiple suppliers. BOM provides 3 examples. Make sure that current and choke specifications match your needs.<\/li>\n
- R5 is the bleeder resistor (3 to 5W size)<\/li>\n
- D9\/D10 are the LED (place only one) either TH 3mm type or SMD (1206). The resistor R6 limits the current through LED.<\/li>\n
- F1 has a standard 20mm fuse holder for PCB. Note that the fuse should be rated to operate effectively at the current required.<\/li>\n
- (+OUT and GND) Output can be taken out of a standard 2-pole block connector or a 2mm bullet connector.<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n
![\"\"](\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2021\/10\/LT-supply-PCB-V03-Dim.jpg?resize=840%2C425&ssl=1\")
<\/a>LT Supply PCB layout<\/figcaption><\/figure>\n Building the board<\/h2>\n
The building is a straight-forward process and is expected the builder to be familiarised and competent in managing valve\u00a0 supply circuits. Please don\u2019t attempt building this board if you are not.<\/p>\n
Given the flexibility of the board, the BOM contains drilling size as well as lead space \/ pitch as guidance for component selection.<\/p>\n
![\"\"](\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2021\/10\/IMG_1236.jpg?resize=840%2C735&ssl=1\")
<\/a>LT supply for 300B<\/figcaption><\/figure>\n You can see a couple of examples here<\/a> and here<\/a>.<\/p>\n
Important note<\/h1>\n
The board is sold as-is for you to work on based on your design. Please don’t ask me for design advice as don’t have the time am afraid to help. If you don’t know how to design your LT supply, this is not a board for you.<\/p>\n
There are plenty of examples out there and you can check in DIY Audio for help if needed. I’d highly recommend you familiarise yourself with PSUD2 if you want to adventure in the design of your own LT supply.<\/p>\n
Order<\/h1>\n
The board is high-quality PCB with ENIG gold finish. \u00a0I made a small batch for my personal use and now am selling the rest of them.<\/p>\n
I will provide detailed BOM and basic build guide upon payment.<\/p>\n
If you are interested ping me a message below:<\/p>\n
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![\"\"](\"https:\/\/i0.wp.com\/www.bartola.co.uk\/valves\/wp-content\/uploads\/2021\/10\/LT-Supply-PCBv03-scaled.jpg?ssl=1\")
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