\nSecond<\/strong>, Check what minimum wire gauge you may safely use.
\nThird<\/strong>, Find a suitable shutoff switch.
\nFourth<\/strong>, Design your chassis to hold motors, wheels, battery pack (as central as possible to avoid damage from other robots) circuit boards, shutoff switch, and finally sensors and any defensive devices such as a scoop\/bumper\/wheelies\/etc.<\/p>\n
Fuses<\/strong> Wire size<\/strong> Shut off switches<\/strong> Mounting and charging your power pack<\/strong> Additional guidelines to ensure the safety of you and your robot<\/strong> Lithium based batteries can give you high power transfer very quickly and with lower weight than traditional rechargeable batteries, but you need to manage this extra power very carefully. This page offers some tips on how to make your robot work safely using Lithium based power supplies. First, Calculate the power drain of your robot […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":80,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"class_list":["post-215","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/mbrobotgames.ca\/mrgwp\/wp-json\/wp\/v2\/pages\/215","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mbrobotgames.ca\/mrgwp\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/mbrobotgames.ca\/mrgwp\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/mbrobotgames.ca\/mrgwp\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mbrobotgames.ca\/mrgwp\/wp-json\/wp\/v2\/comments?post=215"}],"version-history":[{"count":15,"href":"https:\/\/mbrobotgames.ca\/mrgwp\/wp-json\/wp\/v2\/pages\/215\/revisions"}],"predecessor-version":[{"id":864,"href":"https:\/\/mbrobotgames.ca\/mrgwp\/wp-json\/wp\/v2\/pages\/215\/revisions\/864"}],"up":[{"embeddable":true,"href":"https:\/\/mbrobotgames.ca\/mrgwp\/wp-json\/wp\/v2\/pages\/80"}],"wp:attachment":[{"href":"https:\/\/mbrobotgames.ca\/mrgwp\/wp-json\/wp\/v2\/media?parent=215"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nTo calculate the minimum fuse size, use the following formula:
\n(stall amps of largest motor) x (# of motors used) x (multiplier 1.5) = Minimum fuse rating. Choose the next largest fuse size. E.g. (2.2 stall amps)(2 motors)(1.5)= 2.2 * 2 * 1.5 = 6.6 Amps. As Mini\u00ae series automotive fuses come in 2, 3, 4, 5, 7.5, 10, 15, 20, 25, & 30 Amps, and there is no 6.6 Amp fuse, therefore the next larger you can use would be a 7.5 Amp fuse.
\nYou can use glass\/ceramic fuses (Type AGA, AGW, AGC) or the more modern Blade style automotive fuses. If you are tight for space, as on a Mini Sumo then the Mini\u00ae series are small, light weight and although sockets are hard to come by you can use insulated 0.110″ spade connectors. Note* the spade connectors are designed to grip metal terminals that are 0.5mm thick while the Mini fuse terminal is 0.82mm thick so you will need to open them up slightly with a small flat screwdriver.![\"MINIfuse\"](\"http:\/\/mbrobotgames.ca\/mrgwp\/files\/MINIfuse-e1448483388870.jpg\")
<\/a><\/p>\n
\nDon\u2019t use the wrong wire size! Too small a wire gauge will act as a fuse also but it will get hot first and may easily cause a fire. The current rating of the fuse should be the minimum considered when selecting the correct wire size. As a guide, use 16 AWG wire up to 15 Amps, 14 AWG up to 25 Amps and 12 AWG up to 30 Amps. To calculate voltage drop try: http:\/\/www.calculator.net\/voltage-drop-calculator.html<\/a><\/p>\n
\nBe sure to either use a switch that can handle the full power that you have calculated, or use a small switch that trips a relay, SCR or power transistor. Shut off the power as close to the battery as possible, but at the very least it should stop the robot from moving.<\/p>\n
\nA punctured or shorted Lithium polymer battery is a potential incendiary device. PROTECT from being punctured. PROTECT from having the leads shorted. Always use the polarized connectors that came with the battery pack, and never modify them unless approved by your instructor.<\/p>\n
\nNever put Li-Ion or Li-Po cells in series. If you need a higher voltage then purchase a \u201cBrick\u201d or \u201cPack\u201d of the desired voltage\/Amp hr rating which is a series of cells that have been assembled in a factory and contain circuitry to ensure even charge and discharge.
\nOnly use a charger designed for the specific type and size of Li-Ion or Li-Po Battery.
\nNever leave charging Li-Ion or Li-Po Batteries unattended.
\nDo not overcharge lithium polymer batteries. (Please refer to your manual for overcharge limits).
\nNever charge a Li-Ion or Li-Po battery at a faster rate than recommended.
\nIf the battery becomes hot to touch, switch off immediately.
\nWhen a Li-Po battery becomes unstable, it generates heat very rapidly so to be safe purchase a “Li-Po safe charger bag”, preferably one with a handle or strap(Eliminator-RC had one for $20.99). <\/a> <\/a> Then if one does go unstable, the bag will contain the exothermic reaction, though not the smoke. If the charging bag has a handle, grab it, hold it away from your body and get outside as quickly as possible. The charging bag should be used to store Li-Po batteries when not in use, as well as when charging.
\nBe extra vigilant when carrying or connecting batteries to ensure that the battery leads are not allowed to be shorted.
\nAlways store Li-Ion or Li-Po batteries in a safe place, such as a Li-Po safe charging bag or a sturdy, non-conductive box.
\nOnly charge the batteries on a non-flammable non-conducting surface.
\nDo not charge the battery inside or near flammable material.
\nAn area will be designated specifically for charging Li-Ion and Li-Po batteries as this will have sand and easy access to the outside in case of problems. Only NiCad and NiMH batteries will be allowed to be charged in the pit area
\nNever touch a swollen or smoking battery with your fingers, use tongs.<\/p>\n","protected":false},"excerpt":{"rendered":"