30 lines
1.7 KiB
Plaintext
30 lines
1.7 KiB
Plaintext
Economic reduced-loss linear 12 - 13.8V / 2 - 25A power supply built with standard components.
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The circuit features low impedance and good stability by using a TL431 reference and a classic
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2-transistor OP-AMP circuit.
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The total cost of components of this circuit s about EUR10 / USD10 (Q1/2013), plus heat sink,
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housing, and transformer. Board size is about 1/4 eurocard = 3.1" x 2.35". Share with friends!
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The circuit is designed to work with off the shelf standard halogen lamp transformers and as
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an option a thermistor/fan combo like the ones used in PC power supplies.
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The board design uses polygons. After opening the .brd file, first use the DRC command with the
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file 'besupreme.DRC', and then the 'ratsnest' command.
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The board can be made single-sided with only the bottom layer, however for even better immunity
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against high energy rf fields, a top layer is provided.
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Components B1, Q4, and R14 should be installed on the heat sink under the circuit board before
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soldering. The distance between drills for B1 and Q4 is 2.2" = 56mm.
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A distance of 3/4" -1" / 20-25mm between print and heat sink is recommended.
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This design can also be used for different output voltages, here are some examples.
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24V (20-30V): R3=2k2, R13=9k1, C1-C2 40V.
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6V (5-7.5V): R1=0, R2 open, R3=330, R4=150, R8=0, Q4 logic level.
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For maximum currents different to 20A, recalculate the value of C1, C2, R16 to R19. Limits to
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Q4 change accordingly. For max currents above 5A, the high current paths designated by gaps in
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the solder stop must be reinforced on the board by soldering additional copper wires to the traces.
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2013 besupreme.de - share and improve! License under http://creativecommons.org/licenses/by-sa/2.0/ |