Benchtop DC Power Supply with 2 adjustable outputs

prusaprinters

<p>Update:<br/> FrontV2 maintains the 0.75 inch distance between binding posts</p> <p>I was in need of a reliable power supply for my maker space. I need two adjustable outputs, constant voltage/current, and voltages from 3.3 up to 30 V. Having 5A was one goal as well.</p> <p> <figure class="media"> <oembed url="https://www.youtube.com/watch?v=weG6X18faGc"></oembed> </figure> </p> <p>BE CAREFUL! WARNING: Voltage from mains is dangerous and can cause serious injuries or death. BE CAREFUL or ask a professional to help you with the wiring.</p> <p>Bill of materials:</p> <p>1x Mean Well AC/DC LRS 200/36 <a href="https://www.amazon.de/gp/product/B07FM9T9ZV">https://www.amazon.de/gp/product/B07FM9T9ZV</a><br/> 1x C14 socket with switch and 6A fuse <a href="https://www.amazon.de/gp/product/B01H5MK3OI">https://www.amazon.de/gp/product/B01H5MK3OI</a><br/> 2x DC-DC <a href="https://www.amazon.de/gp/product/B07DWX96M9">https://www.amazon.de/gp/product/B07DWX96M9</a><br/> 1x Buck converter <a href="https://www.amazon.de/gp/product/B077VW4BTY">https://www.amazon.de/gp/product/B077VW4BTY</a><br/> 1x 120mm fan, 12V <a href="https://www.amazon.de/gp/product/B002KTVFTE">https://www.amazon.de/gp/product/B002KTVFTE</a><br/> 7x Cable shoes 4.8x0.8 <a href="https://www.conrad.de/de/p/vogt-verbindungstechnik-3805-67-flachsteckhuelse-steckbreite-4-8-mm-steckdicke-0-8-mm-180-unisoliert-metall-1-st-1226359.html">https://www.conrad.de/de/p/vogt-verbindungstechnik-3805-67-flachsteckhuelse-steckbreite-4-8-mm-steckdicke-0-8-mm-180-unisoliert-metall-1-st-1226359.html</a><br/> 2x fuse holders <a href="https://www.conrad.de/de/p/tru-components-tc-r3-12-sicherungshalter-passend-fuer-feinsicherung-5-x-20-mm-10-a-250-v-ac-1-st-1587496.html">https://www.conrad.de/de/p/tru-components-tc-r3-12-sicherungshalter-passend-fuer-feinsicherung-5-x-20-mm-10-a-250-v-ac-1-st-1587496.html</a><br/> 2x Fuses 20x5mm, 6.3A <a href="https://www.conrad.de/de/p/eska-522525-feinsicherung-x-l-5-mm-x-20-mm-6-3-a-250-v-traege-t-inhalt-10-st-533556.html">https://www.conrad.de/de/p/eska-522525-feinsicherung-x-l-5-mm-x-20-mm-6-3-a-250-v-traege-t-inhalt-10-st-533556.html</a><br/> 1x Binding post 4mm, green <a href="https://www.conrad.de/de/p/cliff-tp-1-polklemme-gruen-15-a-1-st-705938.html">https://www.conrad.de/de/p/cliff-tp-1-polklemme-gruen-15-a-1-st-705938.html</a><br/> 2x Binding posts 4mm, red <a href="https://www.conrad.de/de/p/cliff-tp-1-polklemme-rot-15-a-1-st-705914.html">https://www.conrad.de/de/p/cliff-tp-1-polklemme-rot-15-a-1-st-705914.html</a><br/> 2x Binding posts 4mm, black <a href="https://www.conrad.de/de/p/cliff-tp-1-polklemme-schwarz-15-a-1-st-705902.html">https://www.conrad.de/de/p/cliff-tp-1-polklemme-schwarz-15-a-1-st-705902.html</a><br/> 15x Cable shoes M3.5 <a href="https://www.conrad.de/de/p/conrad-components-93014c221-gabelkabelschuh-1-50-mm-2-50-mm-loch-3-7-mm-teilisoliert-blau-100-st-745312.html">https://www.conrad.de/de/p/conrad-components-93014c221-gabelkabelschuh-1-50-mm-2-50-mm-loch-3-7-mm-teilisoliert-blau-100-st-745312.html</a><br/> 4x screws Cylinderhead M4x20<br/> 2x screws Cylinderhead M4x15<br/> 1x screw Cylinderhead M4x6<br/> 25x screws Cylinderhead M3x20<br/> 2 screws Cylinderhead M3x16<br/> 5 screws Cylinderhead M3x12<br/> 2 M3 nuts<br/> Heat shrinking tube, 5mm diameter, about 250mm<br/> 2.5 sqmm wire, 3 colors, rated for at least 6 A<br/> solder stuff<br/> zip ties<br/> 4x selfadhesive rubber feet</p> <p>3D print all the parts once each. Forget about support, rafts, brims etc. Just 3 shells in each direction, and 20% cubic infill. I used standard PLA from <a href="https://dasfilament.de">https://dasfilament.de</a>, and the stuff printed well on my Prusa I3 Mk3. If you have a printer with less then 250mmx200mm print bed, this thing might not be for you.</p> <p>Once you have the printed parts available, and sourced the list above, this was my way to go.</p> <p>BE CAREFUL! WARNING: Voltage from mains is dangerous and can cause serious injuries or death. BE CAREFUL or ask a professional to help you with the wiring.</p> <p>Before you start make sure the voltage switch at the Mean Well is set to the voltage your mains are running on.</p> <p>1.) Mount the Mean Well to the bottom, fix it using M3x20. The screw terminals point to the right<br/> 2.) Mount the back to the bottom using M3x20. Use M4x15 to mount the Mean Well to the back<br/> 3.) Mount DC/DCs, all the binding posts and the fuse holders to the front. From left to right the fuse holders and binding posts go like this: red, fuse holder, black, green, black, fuse holder, red<br/> 4.) Prepare 10cm wires to connect the OUT- of the DCs to the black binding posts, one side just with some solder on it, other side with cable shoe M3.5. Use heat shrink to cover the cable shoe<br/> 5.) Prepare 10cm wires to connect the OUT+ of the DCs to the fuse holders, both sides just with some solder on it<br/> 6.) Prepare 6cm wires to connect the fuse holders with red binding posts, one side just with some solder on it, other side with cable shoe M3.5. Use heat shrink to cover the cable shoe<br/> 7.) connect fuse holders and red binding posts using the cables from 6.)<br/> 8.) prepare 1 cable 15cm long, both sides with cable shoes M3.5, convered with heat shrink<br/> 9.) use M4x6 and connect the cable from 8.) to the front side of the Mean Well, connect the other end to the green binding post<br/> 10.) prepare 2 cables 20cm long, 2 cables 24cm long. One side just with some solder, other side with cable shoe M3.5. Use heat shrink to cover the cable shoe<br/> 11.) Connect Mean Well 36V outputs and DC/DCs. Do not confuse Voltage and ground!<br/> 12.) Prepare 2 15cm wires, One side just with some solder, other side with cable shoe M3.5. Use heat shrink to cover the cable shoe<br/> 13.) Use cables from 12 to connect the buck converter and the Mean Well 36V outputs<br/> 14.) Mount the DCHolder to the back using 2 M3x20 screws, pointing inside the case. Do not confuse voltage and ground<br/> 15.) Mount the C14 socket to its place of the back. Secure it using M3x16 and the M3 nuts<br/> 16.) Prepare 1 cable 20cm, having Cable shoe 4.8x0.8 on one side, and Cable shoe M3.5 on the other side, and cover the cable shoes with heat shrink. BE CAREFUL!<br/> 17.) connect this cable to the earth of the C14, and to earth of the Mean Well. BE CAREFUL!<br/> 18.) Prepare 2 cables 20cm, having Cable shoes 4.8x0.8 on one side, and Cable shoes M3.5 on the other side, and cover the cable shoes with heat shrink. BE CAREFUL!<br/> 19.) Connect Mean Well 240V and the switch of the C14 socket using the cables from 18.)<br/> 20.) Prepare 2 cables 8cm, having Cable shoes 4.8x0.8 on each side, and cover the cable shoes with heat shrink. BE CAREFUL!<br/> 21.) Connect the connector of the switch and the left connectors of the C14 socket itself using cables from 20.) BE CAREFUL!<br/> 22.) Doublecheck all the wiring, you can use a multimeter. BE CAREFUL!<br/> 23.) Doubecheck you can measure connected earth between C14 earth, all M4 screws and the green binding post at the front. BE CAREFUL! Doublecheck not to have a connection from any of the C14 connectors to any 36V connectors of the Mean Well<br/> 24.) Mount the right case to the case, use 9 M3x20<br/> 25.) Mount the left case to the case, use 9 M3x20<br/> 26.) Doublecheck you did not kill any wires when screwing the stuff together. BE CAREFUL!<br/> 27.) Connect the power cord, and switch the device on using the switch at the C14 socket. BE CAREFUL not to touch the mains!<br/> 28.) Trim down the buck converter to deliver 8-10V<br/> 29.) Switch your power supply off, and remove the power cord. BE CAREFUL!<br/> 29.) Solder the fan wires to the outputs of the buck converter without confusing ground and voltage. If there is a socket at the cable, remove it. If there are 3 cables, use the one marked ground as ground, and the middle one as voltage. Mount the buck converter to the DCHolder using zip ties<br/> 30.) Mount the fan to the top, using the screws delivered with the fan. Make sure the fan is blowing the air OUT of the case.<br/> 31.) Close the case using the left M3 screws. Attention: on the fans side use the shorter screws!<br/> 32.) Connect the power cord, switch the power supply on, switch the DC/DC on, set a voltage to each and measure the outputs. Are they delivering the right voltage?<br/> 33.) Mount the rubber feet to the cases bottom</p> <p>Done!</p> <p>Again, BE CAREFUL! WARNING: Voltage from mains is dangerous and can cause serious injuries or death. BE CAREFUL or ask a professional to help you with the wiring.</p> <h3>Print instructions</h3><p>3 shells in each direction, 0.3 mm layer height, 20% cubic infill. No supports, no brims, no rafts</p>