Raptor Flip-Top VV Mod with 20A, 120W dc/dc converter...

[mamu]

Can you show a sketch how you wired it and also what N-FET you are using, BJ? Are you using the 47K pull-down on gate and also the 7.5K on on/off control? Where exactly did you tie in the zener and what is the voltage across the zener?

My wiring is based off how we wired the Fistpack way back when with using an N-FET to handle switch load and also what BigBlue taught us here (do you remember this, BJ? I know some years back, but I save everything for when I need it lol): Low power micro switch MOSFET transistor tutorial

From Nucks' guide:
Source to Batt -
Drain to converter ground
Gate to fire switch, then to Batt + and Vin

We didn't have an inhibit pin on that TI converter from the Fistpack, so I don't think we need to use it unless the zener has to be there.

BigBlue and Bap and Breaktru use a 47K, so I used that as a guide to hold the gate low during startup and to ensure there is no floating charge and to limit the amount of current going through the fire switch and master switch. But I added the zener on gate and am curious what the voltage across the zener is with a 47K pull-down, so that needs to be tested to make sure we're getting the full zener voltage. I'm thinking we're not, but not sure. So we may need the inhibit for the zener. Just not sure til I get the N-FET and can test what's going on.

 

[BJ43]

PSMN1R2-25YLC,115 NXP Semiconductors | Mouser

I used this Fet that Bap recommended with the 47K wired just like Baps drawing. Removed the wires from my original switch and soldered them together one (+) goes to the Vin and the other to the zener and the zener is getting the same full voltage that goes to Vin, so everything is just like your original drawing except now the switch is connected to the N-fet. BTW the zener works and quit firing at 6.6v.

Ok I will admit I did only skim threw the last batch of posts.....That said, am I missing something or wouldn't just using mosfet rated for the needed current be the simplest way and still be able to use a non rated switch?

I like switching the negative side since you can use a n-channel mosfet which typically have lower resistance (rdsON).

Here is a basic diagram and instead of going to the atty they would go the Raptor....and I think you should still be able to use the zener diode for low voltage.

I guess I could have removed the zener and resistor but I wanted to try and keep a LV cutoff.

I remember back when we used this circuit on some of our original mods, still have a few LM2596s with this type of switch somewhere...

Instead of the zener on the gate just leave it where is was original and this switch just turns the whole board off and on. If the voltage gets too low the zener doesn't let it fire on the board even if the Fet is still sending current.

 

[mamu]

I see now. You tied Vin plus on/off control plus zener together on one side of the switch and gate on the other side of the switch, correct? So the 47K at the gate doesn't affect the zener then. Cool!

Way cool that the zener cutoff voltage is working. How was it working with the small N-FET? Not too small?

YAY for bap for leading us on the right track with LVC and no idle current drain! And we can use both a non-rated fire switch and non-rated master kill switch too.

Are you using a voltmeter? Where do you have its ground tied to? Batt ground or converter ground? Since batt ground and converter ground are isolated, I'm thinking if it's tied to Batt ground, then a SPDT switch should be doable for reading both input and output voltage like we've always done. If it's tied to converter ground, then would need to press the fire switch to read input voltage, which would fire the atty.

I'm getting myself confused. I better stop.

 

[BJ43]

I see now. You tied Vin plus on/off control plus zener together on one side of the switch and gate on the other side of the switch, correct? So the 47K at the gate doesn't affect the zener then. Cool!

Way cool that the zener cutoff voltage is working. How was it working with the small N-FET? Not too small?

YAY for bap for leading us on the right track with LVC and no idle current drain! And we can use both a non-rated fire switch and non-rated master kill switch too.

Are you using a voltmeter? Where do you have its ground tied to? Batt ground or converter ground? Since batt ground and converter ground are isolated, I'm thinking if it's tied to Batt ground, then a SPDT switch should be doable for reading both input and output voltage like we've always done. If it's tied to converter ground, then would need to press the fire switch to read input voltage, which would fire the atty.

I'm getting myself confused. I better stop.

I have the voltage meter on battery ground. So far the small Fet is working OK. I have some of these that I may try.

Fet

Some one else recommended this fet on another thread to be used as a fire switch. I don't understand all the specs so I do not know if it is better than Baps for our use, but it is a little bigger and more expensive.

http://www.e-cigarette-forum.com/forum/battery-mods/571916-button-amp-loads.html#post13414257

 

[mamu]

lol I'd say they are more expensive and the continuous drain current is way overkill for our needs, but no harm in that though. All the other specs look great.

I had emailed Vishay a few weeks back when I was thinking of making a lipo mod with one of these buck converters and didn't want to use the inhibit pin for idle current drain.

The rep recommended SUP85N03 or SUP50N03. I also have LU8743 that I found in my stash that is doable and in a smaller size.

I just finished up the OKL2-T20 project for LVC and getting ready to post that, so now will have time for working with the Raptor. The diagram that I posted the other day in this thread was a spin off from what I had been tinkering with and is working with the OKL2-T20. It's a negative logic circuit though and requires a low current FET.

 

[BJ43]

Did you build the passthru yet? Luvin my raptor passthru in my truck.

 

[nexgen91]

awesome thanks, not to worried about max, was just curious for specs

 

[Rapture]

Just curious what happens if you put the zener diode in flipped the other way? Does it still function accordingly for the 6 volt cut off

 

[Rapture]

........ is selling 60amp raptors

 

[mamu]

Did you build the passthru yet? Luvin my raptor passthru in my truck.

I'm sorry, BJ - I missed this post.

No, I nixed the Raptor and the OKL2 for my passthru mod and used an OKR-T10. The enclosure I wanted to use was too small to fit the Raptor and OKL2 boards.

 

[LowOhms]

Are the 22uf capacitors and 4.7k resistor soldered directly to the leads on the chip? Or are they soldered to wire first then soldered to the chip? If they are soldered to wire first, how does the wire size and length of wire affect their function? Any tips on wiring these components would be much appreciated Thanks

 

[Rapture]

I wire the leads of the caps to the leads of the chip along with the 16gauge wires while trying to keep them all as close together as possible so there isn't a big solder ball of mess. I first solder on all the wires then add the caps and resistor after. I'm not sure how anyone else does it though but this works for me.

 

[branflan]

This is how I do mine.

Sent from my SAMSUNG-SGH-I747 using Tapatalk

 

[Visus]

awesome u 2 wow 16ga 2 white heat shrinks in a row, the math for that to happen is mindboggling
nobody usually uses the white cause dirty fast where touched like a magnet to dirt, blue, black, and maroonish red, most common
I use the caps legs and resistor legs as wire wrap like an atomizer coil and make a tight mechanical connection then solder pre-tinned wrapped wire, I almost dont have to solder.

 

[Rapture]

awesome u 2 wow 16ga 2 white heat shrinks in a row, the math for that to happen is mindboggling
nobody usually uses the white cause dirty fast where touched like a magnet to dirt, blue, black, and maroonish red, most common
I use the caps legs and resistor legs as wire wrap like an atomizer coil and make a tight mechanical connection then solder pre-tinned wrapped wire, I almost dont have to solder.

Haha. Really good idea. Now I must sell my personal box and make another one for myself...again

 

[neogen]

could this chip possibly be used instead?

http://apps.geindustrial.com/publibrary/checkout/APTS020A0X?TNR=Data Sheets|APTS020A0X|generic

 

[texanator]

hey yall,
I've been following this thread and also want to build me a box.
Unfortunately seems that all chips are sold out for a while.
Now, is there an updated schematics for the LVC switch, no kill switch version?
I'm not skilled enough to start merging schematics together.

 

[Rapture]

I am trying to figure out a way to wire in a volt meter to show voltage left in the batteries without having to add a switch. I know I can wire it to the voltage in wire but that would make it stay on costant. Any ideas? Basically want the volt meter so I know how much battery I have left so I'm not putting all my trust in that tiny diode. I don't care about voltage to atomizer. I wouldn't mind an on off switch if someone could find me a small panel mount rocker switch. Been searching with no luck. They are all super big.

I'm prototyping a box with no glue or adhesives. I need everything panel mount. Got the 510, pot, battery holder, and fire switch covered. Volt meter/switch is problem

 

[BJ43]

Just wire the meter directly to the batteries with a small push button tact switch on either the pos or neg. The switch does not have to be high amp as the meter uses very little current. You can also use a small snap push button switch, stays on or off after each push. These snap switches are readily available for flashlights and not expensive.

http://www.ebay.com/itm/10PCS-1712-...903?pt=LH_DefaultDomain_0&hash=item5d4d46db9f

http://www.ebay.com/itm/10-x-Torch-...279?pt=LH_DefaultDomain_0&hash=item35c3962b3f

I am trying to figure out a way to wire in a volt meter to show voltage left in the batteries without having to add a switch. I know I can wire it to the voltage in wire but that would make it stay on costant. Any ideas? Basically want the volt meter so I know how much battery I have left so I'm not putting all my trust in that tiny diode. I don't care about voltage to atomizer. I wouldn't mind an on off switch if someone could find me a small panel mount rocker switch. Been searching with no luck. They are all super big.

I'm prototyping a box with no glue or adhesives. I need everything panel mount. Got the 510, pot, battery holder, and fire switch covered. Volt meter/switch is problem

 

[Rapture]

Just wire the meter directly to the batteries with a small push button tact switch on either the pos or neg. The switch does not have to be high amp as the meter uses very little current. You can also use a small snap push button switch, stays on or off after each push. These snap switches are readily available for flashlights and not expensive.

http://www.ebay.com/itm/10PCS-1712-...903?pt=LH_DefaultDomain_0&hash=item5d4d46db9f

http://www.ebay.com/itm/10-x-Torch-...279?pt=LH_DefaultDomain_0&hash=item35c3962b3f

Probably the best bet. Now off to find the smallest one and hopefully one that panel mounts.