http://forums.leaflabs.com/topic.php?id=10564 A place to share, learn, and grow... en-US Fri, 22 Jan 2016 00:22:31 +0000 http://bbpress.org/?v=1.0.2 q http://forums.leaflabs.com/search.php http://forums.leaflabs.com/topic.php?id=10564#post-25065 Sat, 20 Apr 2013 15:47:34 +0000 pyrohaz 25065@http://forums.leaflabs.com/ <p>Hi Gbulmer, my apologies for the clarity. I'm trying to install a switch that can switch the device on or off (without having to rewire the battery connector) When the jumper (I have the rev 5 board) is set to usb, the maple is powered by usb and the lipo battery can charge. When the jumper is set to battery, the lipo is used and isn't charged at all. If I install a SPDT switch between the usb and battery jumpers, will this allow me to charge the battery and the device be switched off (unless usb is present) when the switch connects the USB jumper? When the switch is in the other position, i'd expect it to be ran off the battery?</p> <p>Hope this makes more sense! </p> http://forums.leaflabs.com/topic.php?id=10564#post-24920 Sat, 20 Apr 2013 07:04:57 +0000 gbulmer 24920@http://forums.leaflabs.com/ <p>pyrohaz - I am not clear what you are asking and describing, but I'll give it a shot.</p> <p>What are you trying to achieve? Is it just to disconnect the LiPo battery?<br /> Have you looked at the schematic, or better yet, used Eagle to look at the schematic and PCB for the version of Maple you are using?<br /> I think the schematic contains all the information which we have (maybe supplemented by the datasheet for the battery and battery charger IC).</p> <p>Three of the four pairs of header pins enable <em>one</em> jumper to select which voltage source (USB, external socket or LiPo socket) is fed into the voltage regulators, and hence power the board.</p> <p>So removing the jumper, and wiring a single pole, double throw switch (the right way round) would let you select from two sources, and hence which voltage source is fed into the voltage regulators. This arrangement would not be able to select the third source to feed the voltage regulators.</p> <p>The LiPo charger circuit is connected to the fourth pair of header pins, and hence uses a second jumper. When the fourth pair of pins is connected, the LiPo charger is also fed by the chosen voltage source. It is then 'in parallel' with the voltage regulators. When there is no header on the fourth set of header pins, the LiPo charger is not connected.</p> <p><em>"When the switch is in USB position, will the battery be draining?"</em> Assuming the switch is connected correctly, then the LiPo won't be draining through the voltage regulators. </p> <p>AFAIK, all LiPo batteries have a small self-discharge rate, and so will drain eventually even if they are not in circuit. If it matters, you'd need to do some research to find what that rate is (for example <a href="http://en.wikipedia.org/wiki/Lithium_polymer_battery" rel="nofollow">http://en.wikipedia.org/wiki/Lithium_polymer_battery</a> says 5%/month, but has no reference to back that up). </p> <p>The battery charger is always connected across the LiPo. You'd need to look at the battery charger datasheet to discover how much current leaks through it, and similarly for capacitor C3. I assume it is small compared to a LiPo's internal discharge rate. </p> <p>(Full disclosure: I am not a member of LeafLabs staff) </p> http://forums.leaflabs.com/topic.php?id=10564#post-24884 Fri, 19 Apr 2013 21:08:27 +0000 pyrohaz 24884@http://forums.leaflabs.com/ <p>Final bump? </p> http://forums.leaflabs.com/topic.php?id=10564#post-24513 Mon, 15 Apr 2013 15:42:14 +0000 pyrohaz 24513@http://forums.leaflabs.com/ <p>Bump? :( </p> http://forums.leaflabs.com/topic.php?id=10564#post-24440 Fri, 12 Apr 2013 13:12:40 +0000 pyrohaz 24440@http://forums.leaflabs.com/ <p>Hey guys,<br /> Maple is working beautifully as per! Got my latest project fully working (4 note polyphonic synth with filter, lfo and envelope gen).</p> <p>All i'm wondering is on the battery powered front, how is the LiPo battery wired up to the maple? I've looked at the pcb in person and it looks as if the left side (closest to the socket) of the jumpers is 1 track and the right side goes off to different parts. Now what i'd like to do is install an on off switch. It would merely need to be between "Battery" and "USB", could I simple install an SPDT switch to switch between the two? When the switch is in USB position, will the battery be draining? Do I need to install a DPDT switch to also disengage the charge part of the jumper?</p> <p>Cheers guys,<br /> Harris </p>