you can use them the voltage isnt as important as the value of the cap is. or should i say id use them
Raptor Flip-Top VV Mod with 20A, 120W dc/dc converter...
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you can use them the voltage isnt as important as the value of the cap is. or should i say id use them
Been using my raptor for a week now got a .32ohm build on there..I've noticed that as your battery gets low, your max Vout also goes down with it..like if you set it at 6v, it won't fire 6v anymore once the battery gets to around 7.8v..then I have to reduce output for it to fire properly..then lower as the battery goes down some more. Now I'm at 7.1v and I can only fire at 4.5v max. Is this a normal behavior?
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That doesnt sound right. I try not to run mine under 7 volts but even at that it is still firing good, but saying that I dont run mine at 6 volts either. It sounds like battery sag, or a bad cell, maybe a wiring issue like the vout is to long of a run. I would start by looking at the battery's though. There is one more thing I can add but I have to go find the answer it has something to do with the caps or sense pin I will post back.
Here is a cut and paste from Mamu and someone else
Re: Tinkering with the Naos Raptor - 20A, 120W dc/dc converter...
« Reply #4 on: December 22, 2013, 03:11:19 AM »
Quote from: Breaktru on December 21, 2013, 08:26:27 PM
Great job and a very nice controller. I've seen that one before. As a matter fact I sent for a free sample a couple of years ago but never received it.
That's strange that not using the on/off pin would drop the output voltage. Anyway it's a good thing using it with the zener for cut-off. Well done mamu :rockin smiley:
Thanks!
Yeah it is strange. When I first set it up I did so without the control pin and ran it through various voltages. Couldn't get loaded volts past 5.0v no matter what. Hooked up the control pin and got max 5.9v loaded. Nothing else changed but adding the control pin.
Quote from: CraigHB on December 22, 2013, 01:46:35 AM
That's a pretty cool module.
I looked over that data sheet a bit. Output is impressive. It does need input capacitors. It doesn't carry those onboard, look at page 12 of the data sheet;
I actually have the same input capacitance requirement for the buck-boost converter I'm working on. I'm using 2x22uF MLCC caps. These are the best ones I've found, really nice characteristics.
Data sheet says to leave the on/off pin floating if not using it so it shouldn't have any affect on output. Maybe you should try tying that pin to Vin instead and see if that makes any difference.
I was looking for a 20A module and with max 6v output and this appears to be the only one. All others max at 5.5v.
Thanks for the clarification about the input cap.
I had ordered these caps and should get them Monday or Tuesday - GRM32CF51C226ZA12L Murata Electronics North America | 490-3392-1-ND | DigiKey and GRM32ER61C476ME15L Murata Electronics North America | 490-3888-1-ND | DigiKey. But think I will order the ones you recommend and use them instead.
So - prob a n00b question here :laughing: why 2x22uF caps and not one larger, say 47uF, cap? I googled to find the answer but no luck. Is it along the same lines as paralleling 2 fuses to lower the resistance? Does paralleling 2 caps double the capacitance as it doubles the current in fuses?
Re: Tinkering with the Naos Raptor - 20A, 120W dc/dc converter...
« Reply #4 on: December 22, 2013, 03:11:19 AM »
Quote from: Breaktru on December 21, 2013, 08:26:27 PM
Great job and a very nice controller. I've seen that one before. As a matter fact I sent for a free sample a couple of years ago but never received it.
That's strange that not using the on/off pin would drop the output voltage. Anyway it's a good thing using it with the zener for cut-off. Well done mamu :rockin smiley:
Thanks!
Yeah it is strange. When I first set it up I did so without the control pin and ran it through various voltages. Couldn't get loaded volts past 5.0v no matter what. Hooked up the control pin and got max 5.9v loaded. Nothing else changed but adding the control pin.
Quote from: CraigHB on December 22, 2013, 01:46:35 AM
That's a pretty cool module.
I looked over that data sheet a bit. Output is impressive. It does need input capacitors. It doesn't carry those onboard, look at page 12 of the data sheet;
I actually have the same input capacitance requirement for the buck-boost converter I'm working on. I'm using 2x22uF MLCC caps. These are the best ones I've found, really nice characteristics.
Data sheet says to leave the on/off pin floating if not using it so it shouldn't have any affect on output. Maybe you should try tying that pin to Vin instead and see if that makes any difference.
I was looking for a 20A module and with max 6v output and this appears to be the only one. All others max at 5.5v.
Thanks for the clarification about the input cap.
I had ordered these caps and should get them Monday or Tuesday - GRM32CF51C226ZA12L Murata Electronics North America | 490-3392-1-ND | DigiKey and GRM32ER61C476ME15L Murata Electronics North America | 490-3888-1-ND | DigiKey. But think I will order the ones you recommend and use them instead.
So - prob a n00b question here :laughing: why 2x22uF caps and not one larger, say 47uF, cap? I googled to find the answer but no luck. Is it along the same lines as paralleling 2 fuses to lower the resistance? Does paralleling 2 caps double the capacitance as it doubles the current in fuses?
I made 3 boxes for friends all are the same lol. We get 6v output don't get me wrong until remaining battery goes down to 7.8v then output starts to diminish as well. 5.8, 5.5, 5.2..and so on.
In another test, a set of fully charged vtcs lasted me 2days set @4.5v the whole time.
This is all voltage underload of course.
In another test, a set of fully charged vtcs lasted me 2days set @4.5v the whole time.
This is all voltage underload of course.
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you should start seeing that at 6 volts not as high as you are recording. If you read my last post it talks about not getting over 5v and the solution to the problem.
Hope it helps
Hope it helps
I answered your pm, your not using the sense pins I believe that is the problem. There may be someone else can chime in? He cannot reach the 6 volt mark on three different mods. The sense pins are not being used from the photo's he sent me can anyone add to this.
Using/not using Sense is not the problem as Sense would only help the converter compensate up to 0.5v loss at output.
If you're trying to run a 0.32 ohm coil @6v - that's 112W and 19A. That kind of load alone will cause some batt sag and output voltage drop, so you're most likely not going to be able to run 6v output loaded for very long if at all. The batt sag under load will affect what the converter can put out as it needs a voltage margin to run efficiently.
And if you haven't optimized input/output wiring and/or are using high contact resistance batt contacts and/or batts that have high internal resistance there will be an increase in circuit resistance which will cause a huge batt sag and volt drop at that load.
If you're trying to run a 0.32 ohm coil @6v - that's 112W and 19A. That kind of load alone will cause some batt sag and output voltage drop, so you're most likely not going to be able to run 6v output loaded for very long if at all. The batt sag under load will affect what the converter can put out as it needs a voltage margin to run efficiently.
And if you haven't optimized input/output wiring and/or are using high contact resistance batt contacts and/or batts that have high internal resistance there will be an increase in circuit resistance which will cause a huge batt sag and volt drop at that load.
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@rhelton , sorry for not yet replying to your pm but thanks for taking the time helping out. For the record, my sense pins are connected and I can fire 5.95v loaded fine until battery life goes down to 7.8v or so then only it starts diminishing. Yesterday I tried a .6ohm coil on there and it fired at max Vout no problem until below 7v batt life so I was happy.
@mamu , thanks for that..was so relieved reading your post. Now I can sleep soundly
@mamu , thanks for that..was so relieved reading your post. Now I can sleep soundly
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Thanks Mamu I wasnt 100% sure, I dont vape that low but I thought the 20amp boards could handle that.
Now I know
Now I know
The 20A boards can handle high loads if circuit resistance is optimized for minimal interference. Plus these boards are typically used with a 12V source in electronic applications, but we use an 8.4V source.
What drains more battery..a lower ohm coil or a higher ohm coil firing at the same wattage? Or are they the same?
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Hang on, im pretty sure this 270$ mod is a polished Raptor mod. Read the description.
Im paraphrasing It says it uses a GE chip,vv 3.5-6v, capable of 120w, with a .3 ohm limit....
http://www.vapordna.com/mobile/prod...-Voltage-mod-by-Project-Sub-Ohm-p/lm0001.htm=
I hope it at least comes with a digital pot, and a screen like the dna's
Im paraphrasing It says it uses a GE chip,vv 3.5-6v, capable of 120w, with a .3 ohm limit....
http://www.vapordna.com/mobile/prod...-Voltage-mod-by-Project-Sub-Ohm-p/lm0001.htm=
I hope it at least comes with a digital pot, and a screen like the dna's
Hang on, im pretty sure this 270$ mod is a polished Raptor mod. Read the description.
Im paraphrasing It says it uses a GE chip,vv 3.5-6v, capable of 120w, with a .3 ohm limit....
http://www.vapordna.com:80/littlemaN-Variable-Voltage-mod-by-Project-Sub-Ohm-p/lm0001.htm=]littlemaN Variable Voltage mod by Project Sub Ohm[/url]
I hope it at least comes with a digital pot, and a screen like the dna's
I think thats what it is, im pretty sure it is, and I do believe that Todd did a review on this mod awhile back.
I've got a few chips on the way, as well as most of the little bits. Still looking for smaller switches to fit inside a 1590g box and a fire button with a smaller "internal footprint." I like the bulger AV button I put in my first mod, an unregulated mosfet box, but it takes up a LOT of space in the box. I'd like to find something smaller in diameter, but I don't like the warty 12mm buttons from e-switch. I hate being picky, buts it's my row to hoe. When things start coming together, I'll put up some pics.
12 x 12 mm tact with 10 mm cap:
10 Pcs PCB Momentary Tact Tactile Push Button Switch 12 x 12mm x 12mm 4pin Cap | eBay
10pcs Momentary Tact Tactile Push Button Switch 12 x 12mm x 10mm 4 Pin DIP Cap | eBay
This one has a 8mm cap:
10 Pcs PCB Momentary Tact Tactile Push Button Switch 12 x 12mm x 8mm DIP Cap | eBay
Thanks for the heads up, David. In the future, I might try a tact button, but for the first build, It's going into a custom CNC aluminum box originally intended as a unregulated mosfet box. It's already cut for a big gnarly AV button.
Not sure if someone has stated this before but what is the best gauge wire to use for this build? I have 16, 18, and 20 all stranded. I've seen 22, 20, and 18 used in different parts of the build all from different people.
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