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View Full Version : wiring check: NBv2 with recharge port, AV, LED, speaker



griva86
08-03-2014, 12:56 AM
Hello all,

This is my first build, and I am excited! Thanks to the tremendous amount of info you have all put up here for us, and HUGE thanks to Tim for the shop. I have spent weeks and then some reading, but still have quite a bit to learn. I am starting with a pretty basic build and requesting a wiring check.

First, a few questions that I could not find the answers to...if there is a thread you think would be helpful, please feel free to point me in the right direction:

1. What size wire is best for wiring a basic saber? I can't seem to find this info. The shop has 22g, 24g, and 26g.
2. I noticed that the NBv2 has a 3.3v accent pad which Erv mentions can be used for AV switches, but I have seen other wiring diagrams that have this coming straight off the line from the battery to the main LED. It seems that this second method would easier to use since a split near the AV switch and the LED would lead to less wiring "spaghetti" inside. Any reason not to do this?

Now for the wiring (thanks to dgregory, the schematic is shamelessly stolen from his post as it helped me a lot):

http://i1293.photobucket.com/albums/b585/griva86/Mobile%20Uploads/2014-08/85DF3483-1C1A-4A5A-AA3A-716C397ADE62_zpshhycrdef.jpg (http://s1293.photobucket.com/user/griva86/media/Mobile%20Uploads/2014-08/85DF3483-1C1A-4A5A-AA3A-716C397ADE62_zpshhycrdef.jpg.html)

LED Calc
blue rebel star MWS
R=(3.7v-3.2v)/1A = .5 ohms
P=(3.7v-3.2v)*1A = 0.5 W

AV LED
white short momentary
R=(3.7v-3.0v)/.02= 35 ohm
P=(3.7v-3.0v)*.02= 0.014w

3. For the main LED, would I choose the .47ohm/.5w, the 1ohm/2w, or the 2ohm/1w resistor for the main?
4. For the AV switch, would I choose 82ohm/.25w resistor? I could always cheese out and use the DynOhm :-)
5. If I choose to use an accent light for power indicator to function in place of the AV switch light, could I just pull the +/- from the AV switch over to an accent light (with appropriate resistor) and have the same wiring otherwise?

Thank you in advance for any help you can give!

Forgetful Jedi Knight
08-03-2014, 07:21 AM
Welcome to the Forums.

To answer your questions:

1. Technically they all would work. Smaller gauge (26) is preferred, and tends to be easier to work with.
2. It depends on how you want the switch to act. If you want it to light up when you pull the kill key, but before you turn the saber on, you would need to use the 3.3V pad. Otherwise, it would come on ONLY when the saber is turned on.
3. The .47Ohm/.5W would be fine. They were just added to the store at my request just for this situation.
4. That would be fine.
5. Yes.

griva86
08-03-2014, 09:34 AM
Thank you so much for the fast reply! I have read a million of your posts and they are so helpful. I have no experience with electronics and only my basic physics from college to rely on. I did pick up the Mims book on Erv's rec in a random post but have found it a little difficult to understand for my brain, which I think works better with conversational writing. If you have another book you think helps with any understanding of wiring for sabers, I would love to hear it.

For the light, I did want it to turn on upon removing the kill key, so I will plan to use the 3.3v pad.

1. It is unclear to me why wiring from the 3.3v pad would turn the attached LED on upon pulling kill-key but this would not be the case if I wired the + directly to the battery. Since in the wiring, it shows the (-) running through the recharge port then directly back to the battery with key-kill-out (internal bridge), doesn't that complete the circuit even without running through the 3.3v pad? I would think that wiring the + directly to the battery would be bypassing the NB completely and therefore there would be no regulation of this current. Can you help me understand this?
2. Does the wiring look ok? You kindly answer the number questions, but did not mention the wiring diagram and I don't want to fry anything.
3. I was planning to use the 18650's in TCSS per Erv's rec for the NB, but Tim is currently out. I could pick up the 18650's at BatteryJunction but would prefer to support Tim. Is there any reason not to use an 3.7v 18500? My understanding is that the 5 digit number is simply sizing of the battery housing, but I wasn't sure why the NB manual would specify 18650 or 14500.

griva86
08-04-2014, 08:26 PM
To answer my own question, I have seen other builds in the forums with 18500 used instead of 18650, so I ordered them...only mention I see of difference is the amount of run time, which makes sense given the size of the battery. I'll let you all know if I have any probs for future posterity what may read my thread...

Silver Serpent
08-04-2014, 08:38 PM
18500 batteries are shorter in length than the 18650 batteries, but are the same diameter. They also have a shorter runtime. That's the only difference.

griva86
08-05-2014, 08:56 PM
Thanks Silver Serpent, that's what I initially thought but was just confused as to why Erv would specifically list 14500 and 18650 in his documentation for NBv2. I had the same question as to why 4 AA (1.5vx4=6v) would be ok when the board max is 3.4-5.5v but he does not list 4AAA (1.2vx4=4.8v) as a recommended power source. I had initially ordered a 4xAAA speaker MWS for use in my saber but then abandoned it when I saw that it was not on the "approved" list.

Silver Serpent
08-06-2014, 04:33 AM
Erv recommended the 14500 and 18650 sizes because they're the two most common sizes of li-ion batteries.

If you take a second look at the NBv2 manual, you should notice that Erv doesn't recommend 4xAA alkalines (1.5vx4=6v)with the NB. He states that you can use 4xAA NiMH (1.2vx4=4.8v) safely.

You can find alkaline or NiMH in AA and AAA varieties, but their respective voltages don't change based on battery size.

griva86
08-07-2014, 07:54 AM
Ah, so I CAN use AAA NiMH batteries (as I can use AA), the voltage is the same (1.2vx4=4.8v) but the mAh and therefore runtime will be different?

I was not sure if there was something inherently different about the way a 18650 vs 18500 vs 14500 would drive a system based on battery type or properties (given the same voltage) or if this was just a capacity difference. Same for the AAA vs AA NiMH batteries. I seem to remember reading in the forums that alkaline batteries were not recommended, and again I was not clear as to why 3xAAA alkaline (1.5vx3=4.5v) would not be acceptable even though it is within the operating voltage of the board.

Forgetful Jedi Knight
08-07-2014, 08:02 AM
Ah, so I CAN use AAA NiMH batteries (as I can use AA), the voltage is the same (1.2vx4=4.8v) but the mAh and therefore runtime will be different?

I was not sure if there was something inherently different about the way a 18650 vs 18500 vs 14500 would drive a system based on battery type or properties (given the same voltage) or if this was just a capacity difference. Same for the AAA vs AA NiMH batteries. I seem to remember reading in the forums that alkaline batteries were not recommended, and again I was not clear as to why 3xAAA alkaline (1.5vx3=4.5v) would not be acceptable even though it is within the operating voltage of the board.

Alkalines aren't recommended because their discharge rate is not great and the runtimes are very short compared to Li-ions. Even the NiMH don't perform as well as Li-ions.

griva86
08-08-2014, 10:18 PM
Ah, ok. Thanks for the response, all!

griva86
09-02-2014, 01:26 AM
Ok, so I finally started building. I ended up abandoning the recharge port because it would not fit with my current dimensions. So much for my planning. Didn't realize that AV buttons would block chassis, but you live and learn.

So i modified my schematic to the following:
http://i1293.photobucket.com/albums/b585/griva86/Mobile%20Uploads/2014-08/7581d1a3-0b7c-45c8-a8e0-3b534180fd7f_zpsf8da90e7.jpg (http://s1293.photobucket.com/user/griva86/media/Mobile%20Uploads/2014-08/7581d1a3-0b7c-45c8-a8e0-3b534180fd7f_zpsf8da90e7.jpg.html)

I wired it up, then plugged in the battery. The AV light turned on but nothing else would. I rechecked my wiring. Everything looked good. Then I noticed the dynaohm for the AV MWS part from TCSS was on the red line. I wired black as positive. Doh. Okay, so I re-wired everything. Plugged it in, AV light comes on but nothing else. I check my wiring again and, like an idiot, when I re-wired everything I put the LED- wire on the momentary pad and vice versa. Doh ^2. I de-solder these and swap them. Plugged it in, it made a clash sound. I pushed the AV and I heard the ignition, the main LED came on, and there was a continuous string of swings and clashes. I thought it was just sensitive (all the board is sitting in its chassis on the table) so I hit the AV and it de-ignited.

Awesome, it seems like it works. So I unplugged all my JSTs and loaded it in to the hilt. I plugged it in, the AV lights up and there is a clash sound. I hit the ignition, and I get nothing. I unplug all the JSTs and reconnect them, then do it again and I get the same result. I take the chassis out of the hilt and check all the wiring plus the connections, suspecting I pulled a wire loose in the cram-fu process. The wiring is as I planned and there are not loose wires. I deduce the following:

1. since the AV light comes on, I know the power is coming out of the battery properly.
2. since the speaker is making the same clash sound each time it is powered up, the board must be getting power and sending it to the speakers. That means Bat+ and Bat- as well as Sp+ and Sp- are wired correctly.

That leaves the LED pad and the momentary. I figured that problem is probably the momentary pad since this is upstream of the LED. I de-solder this and re-solder it. I leave the chassis outside the hilt and plug everything in. Now, the AV lights, the main LED comes on for about 2 seconds, and I hear the speaker boot up. Then the main LED goes off, the AV Light is still lit, but hitting the AV button does nothing.

I am at a loss now. Given the variable behaviour, it seems based on my reading that this suggests a short. I have looked over every connection on the board probably 15 times from both the top and bottom view. All of my wire splices that I did were tug-tested and shrink wrapped. I have included images of the board below. The only thing I can see is that the Sp+ and Momentary pads have a lot of solder and they are close, but the are not touching. This is actually a little uglier than right before my last solder-desolder as the soldering job was cleaner before i tried to re-do it, and it was not working properly then either.

http://i1293.photobucket.com/albums/b585/griva86/Mobile%20Uploads/2014-08/AD89D63A-6399-4284-8819-DD57616BB8F0_zpsaszlke2y.jpg (http://s1293.photobucket.com/user/griva86/media/Mobile%20Uploads/2014-08/AD89D63A-6399-4284-8819-DD57616BB8F0_zpsaszlke2y.jpg.html)
http://i1293.photobucket.com/albums/b585/griva86/Mobile%20Uploads/2014-08/D8BF1CDD-2F01-4567-B9F6-03617AFFEC4A_zps76vumtis.jpg (http://s1293.photobucket.com/user/griva86/media/Mobile%20Uploads/2014-08/D8BF1CDD-2F01-4567-B9F6-03617AFFEC4A_zps76vumtis.jpg.html)

Thoughts? I appreciate any help...

<yes, I realize I'm not the sharpest tool in the shed having had to re-solder literally 4-5 times because I can't follow a basic instructional...hopefully this did not damage the board...>

Silver Serpent
09-02-2014, 05:20 AM
Have you tried charging the battery? If you are experiencing erratic behavior (wild swing sounds, not turning on/off properly, etc), then most of the time your issue is a low battery. Charge it to full and then see how it works.

You also have too much exposed wire on those connections. I would try to redo the ones with exposed wire and keep the exposed part as short as possible.

griva86
09-02-2014, 01:14 PM
Battery charge was fresh and I tried a second battery same effect. I am puzzled.

When you say that there is too much exposed wire, are you talking about exposed wire sticking through the contact pad hole or too much wire where it has been stripped on the top side of the board, like wires 1,2, and 5 above (from top to bottom, 6 and 7 being the green speaker wires). I was trying to strip less (like 2-3mm) but the wire cover was melting when I was soldering anyway, so I thought it would be better to control the removal of the wire cover...

Silver Serpent
09-02-2014, 05:42 PM
A few things to help with that:

After you strip the insulation from your wires, pre-tin the exposed wire with a bit of solder. Then you can trim the wire to just long enough for a proper connection.

Pre-tin the pads as well, though they've likely got enough solder on them now.

If the pad and wire are both pre-tinned, then it should only take a second or two to make the connection. If it takes longer and the wire insulation is melting, then you need to use a hotter iron (or let your iron heat up more). It's counter-intuitive, but a cold iron will burn things more easily than a hot one.

The long exposed sections of the wire connected to the board could be touching just enough to give you erratic behavior. Everything else looks to be isolated enough that touching the hilt isn't a problem. If you have a recharge port, check that carefully as well. Those are a common source of grounding to the hilt.

griva86
09-03-2014, 08:27 AM
Ah, thanks for the tips. The tip about tin-then-trim is great. I'll re-solder the joints to the board, just need to pick up some de-soldering wire to clean up a bit.

So I included a video clip of the boot up now. Actually, the AV light is no longer coming on. The only thing I have done since the last description of boot up was that I add a resistor before the LED, which I had forgotten previously. This makes me think maybe something came loose in my connections. I currently have an X formation on the power line. The bottom right leg is the battery, the bottom left is going to the board, the top right is going to the AV switch and gives off a branch to the main LED (before the resistor to the AV), and the top left is going to the momentary switch. Is there any issue with this 3-branch formation? I would imagine not, as long as the connection is good.

http://i1293.photobucket.com/albums/b585/griva86/Mobile%20Uploads/2014-08/th_DD5A3FF3-27AB-4A6D-9BE0-1728A93EC666_zps6razmw1j.mp4 (http://i1293.photobucket.com/albums/b585/griva86/Mobile%20Uploads/2014-08/DD5A3FF3-27AB-4A6D-9BE0-1728A93EC666_zps6razmw1j.mp4)

Darth Kato
09-10-2014, 12:53 PM
What chassis discs did you use in that picture? Is that just the NBv2 with 18650 chassis disc?

griva86
09-22-2014, 01:09 PM
Yes, that is exactly right. Works like a charm. I also have a sled from shapeways that I'm looking forward to trying.