Homemade 3.7 volts passthrough question...

[AdamM]

Hi all,


I have been using a SB with LR attys for months now and I love it. However, I'd like to be able to use my computer as a power source without the need for a battery.

I would like to make a passthrough but I'm unclear on what parts I need. I was hoping someone could briefly outline the kinds of parts I would need to get from madvapes in order to make a 3.7 volt power source. They have a lot of different parts, and I'm unclear as to what I need to be looking at. I don't need exact part numbers or anything (though that would be cool ) rather I just want to know the kinds of things I need.

It would be cool if I could I could still use the Silverbullet switch, but I'm guessing this is not likely to be possible.

Thanks,
Adam

 

[Java_Az]

First off a computer USB port does not supply enough amps for LR vaping. You can use a 2 amp USB Hub or a 2 to 3 amp USB wall wart But your going to be stressing a computer vaping off it. Not advised really since a powered USB hub or a wall wart costs 10 bucks and computers cost several hundreds of dollars at the least.

Getting the 5 volts of a USB to 3.7 volts is the next problem. Lots of ways to do that , But i am not aware of any documentation here in the forums. The best way would be a adjustable regulator set to 3.7 volts but thats going to take up space. If you use Anti vandal switch like what the silver bullet uses you might just have the room because those switches are fairly big so your going to have to use a big tube or box to slap it into.

Here is a link to the type of switch you want PV2 anti-vandal switches | water resistant vandal resistant | long life switch | www.e-switch.com

 

[AdamM]

Thanks Java,


My power supply can handle the extra draw, so I'm not concerned about that. I assume you mention this in case I have some off the shelf dell or something, haha. Unless there is some bottleneck imposed on the USB current due to the kinds of parts required for the passthrough, then I'm not concerned.


I appreciate the advice, but I am hoping someone could give me a bit more detail on the parts. I now have an idea of what kind of switch to get, but what about the rest?

 

[Java_Az]

Thanks Java,


My power supply can handle the extra draw, so I'm not concerned about that. I assume you mention this in case I have some off the shelf dell or something, haha. Unless there is some bottleneck imposed on the USB current due to the kinds of parts required for the passthrough, then I'm not concerned.


I appreciate the advice, but I am hoping someone could give me a bit more detail on the parts. I now have an idea of what kind of switch to get, but what about the rest?

power supply can handle the amps for sure. But the USB comes off the motherboard. Depending how the Motherboard makers designed the circuit it might just cut off right away with over current protection. Some mother boards designs dont have that and it will give what amps it can till you damage your motherboard. USB 2.0 standard has a maximum of 1.5 amps in charge mode. A LR atomizer thats 1.5ohms @ 3.7volts will require 2.46amps. So @ 2.46 amps best case is your mobo has protection and will shutdown. If the motherboard doesnt have protection and you keep drawing 2.46 amps threw it it will eventually fry the traces in the board.

I vape directly off my power supply all the time bypassing the motherboard. But most folks are not going to know how to wire a USB port into the 5 volt rail. So i usually recommend a powered USB Hub or a high amp USB wallwart

 

[AdamM]

I've got an 850 Quatro and it just so happens that I have a free rail connection and lots of cables to work with (PS, USB, as well as ps/2 to USB adapters and other random bits I have accumulated). If you are willing to try and explain how to rig it, I would be willing to do it

Feel free to PM me. I would very much appreciate it I'm willing to purchase any tools that might be required eg. Soldering Iron

 

[Java_Az]

Well it is pretty easy. If you have a extra back panel USB like in this picture

And you dont care about cutting it up. The black wires are your ground. There should be a solid red one that's your positive for one of the ports. Then you need a female romex i just used a extra one laying around and cut the sata power connectors off it. For romex you have black wires 2 of them they are your grounds. Then you will have a yellow and a red wire. Yellow is 12 volts the Red wire is 5 volts. So it is red to red and black to black when wiring the USB to the female romex. Then you just have to find a free male romex to have sex with your newly created female and you will be making vapor babies

 

[AdamM]

haha, ....ing awesome Thanks dude. I'll get on this right away and let you know if i run into any troubles.

 

[AdamM]

Does this look right so far? Do I just cut the USB wires from the connector then splice them according to the lines and leave the other wires capped off?

 

[Java_Az]

Yeah that looks correct. You for sure want to cap off the yellow wire to make sure it doesnt hit any grounds. Also just to warn you that USB port will have access to the rated amps of your 5 volt rating on your PSU. Like mine is rated to 25 amps. Ideally you might want to put a 3 amp fuse on the between red wires. I skipped doing that but you might want to think about it for safety. Make sure you test your PT for a short after making it , before plugging it in.

 

[AdamM]

Ideally you might want to put a 3 amp fuse on the between red wires.

I'm assuming that with a fuse in place, were there a power surge on my system, it would prevent the heightened current from reaching my PT? Do fuses come in different types, or should I just find any 3 amp fuse? Would it be possible to find a mini breaker rated for 3 amps so that in the event of a surge I don't need to replace the fuse? Can I acquire either of these at a local hardware store/home depot/rona?

Are there by any chance modules of some sort intended for these kinds of electronics projects that will make this assembly cleaner. What I mean by this is some kind of board that has places and clamps for wires...this is what I'm thinking of, though I don't know if it's silly:

Make sure you test your PT for a short after making it , before plugging it in.

haha, definitely will do.

Could you recommend a USB PT for me? I'm not exactly sure what to get. I'm confused because it seems like there are PT s that use batteries and ones that don't....I'd like something that is just a direct connection for power to my atty.

Thanks so much for walking me through this. I also have a feeling that some others might find this useful. Assuming all goes well, I'll be sure to post assembly pics.

 

[VpnDrgn]

Yellow is 12 volts the Red wire is 5 volts.

Java,

How many amps will that 12v wire provide?
I am putting together a VV PT for use in the living room with a 12v transformer.
After seeing a youtube video on using a PC power supply for 12v charging I was wondering
if I could hard wire a dc jack into my PC case using one of the extra power cables floating
around in the case.You Know, just for the tinker factor. I can just bring the transformer
over to the desk if it is more risky than it's worth.

 

[Java_Az]

Was more worried about the PT having a short. Having access to that much amperage it will fry the USB wires pretty quickly. PT with batteries are not really PT's although they are called that. You want to get you a 5 volt passthrough is what they are sold as. Only thing is if you go that route LR are more then likey going to be too hot. A regular ohm atomizer should preform about the same @ 5 volts as a LR @ 3.7 volts. I make my own passthroughs so not sure what to recommend for you might want to look in the product reviews section. Easiest fuse to get off hand would be a automotive one. Any parts store should have one. For a reset-able one you can look into PolySwitch's not sure where you can get them where your at. Here in the states Digikey has some.

 

[AdamM]

You want to get you a 5 volt passthrough is what they are sold as. Only thing is if you go that route LR are more then likey going to be too hot.

Out of curiosity, is there something I can integrate into this new modification that would allow me to regulate the voltage?

Looks like those resettable switches are typically sold in bulk. I'll check with the local college to see if they have an singles hanging around.

Thanks for all the help. I'll keep you posted.

 

[Java_Az]

Java,

How many amps will that 12v wire provide?
I am putting together a VV PT for use in the living room with a 12v transformer.
After seeing a youtube video on using a PC power supply for 12v charging I was wondering
if I could hard wire a dc jack into my PC case using one of the extra power cables floating
around in the case.You Know, just for the tinker factor. I can just bring the transformer
over to the desk if it is more risky than it's worth.

Really it depends on the power supply. I have a multi rail PSU which is four 12 volt rails 2 @ 22 amps and 2 @ 25 amps. But also have a high end gaming PC with a 850 watt PSU made for running multiple video cards. Your PSU should have a Sicker on it with all the amp ratings. Unless you have a old computer or a cheap one you shouldn't have any problems charging off the PSU's 12 volt rail. If you tell me what computer you have i might can find out more.

Out of curiosity, is there something I can integrate into this new modification that would allow me to regulate the voltage?

Looks like those resettable switches are typically sold in bulk. I'll check with the local college to see if they have an singles hanging around.

Thanks for all the help. I'll keep you posted.

Yeah you could regulate it for sure. But that is a whole new story. Best bet would be to get a switching regulator off ebay that can take a input of 12 volts. Most regulators have a pretty big drop out voltage. For example this regulator sitting in from of me, If i power it off of 5 volts the highest output voltage i can get is 4.1 volts. so the drop out is .9 volts. 4.1 wont cut it for me depending on what juice and atomizer i am using my sweet spot is 4.2 to 4.9 volts. I might just go ahead and design a 5.1 bay for the front of a PC with variable voltage USB and maybe even a build in ego charger nice LED voltage read out. might be pretty cool

 

[VpnDrgn]

I make my own PC's. I prolly still have the box that the psu came in. ( can you say pack rat )
I'll check it out. Thanks

 

[AttyPops]

Yea! Java's back! Cool stuff _AZ.

Along the same lines as the above post on a vv pt:

OK techno dudes (and dudettes?) .... Now let's just say, hypothetically, that I wanted to make a vv PT. Let's also assume that I had a wall wart or charger hub with a lot of amps and TWO, count them, TWO ports.

As long as we are assuming a bunch of stuff, let's assume that we don't wish to use a booster. We want a regulator (switched, or linear, doesn't matter to me with mains power).

What's the simplest voltage doubling circuit we could design to take 2 5 v usb inputs, make it around 10v and then use a vv regulator? If you just use a Y-cable, you get double amps, not double volts... true? So, what circuit do we use?

Also note that conveniently there are 4 wires in a USB cable.....

Of course, we're using DC inputs here.

 

[VpnDrgn]

Atty,

If I understand you, you want to take the two 5v ports and power one typ VV regulator?
Why not just use this?

I am building a VV PT using a pre-made regulator, like in Mamu's build, in a small box with just
a switch, voltage meter, regulator, and dc jack to match plug on AC adapter.

Talk about the 12v cables in a pc made me think of wiring in a dc jack on the side of my case
so that I could plug in my VV PT using a cable with male dc jacks on both ends.

12v's means I don't have to worry about the 2v dropout on the regulator.
Should be pretty straight forward.

 

[AttyPops]

You can! It was, as stated, hypothetical. The idea being voltage doubling followed by a adj regulator. Also, 5v is a USB standard. There are many other power supplies, 9 volt, 12 volt, etc. including ones that are already vv. So, good thinking, and good luck with your vv-pt.

What I was getting to was finding a voltage doubling circuit that is easy and inexpensive so no need for a booster (the easier way, but pricey).

 

[WillyB]

... OK techno dudes (and dudettes?) .... Now let's just say, hypothetically, that I wanted to make a vv PT. Let's also assume that I had a wall wart or charger hub with a lot of amps and TWO, count them, TWO ports.

As long as we are assuming a bunch of stuff, let's assume that we don't wish to use a booster. We want a regulator (switched, or linear, doesn't matter to me with mains power).

What's the simplest voltage doubling circuit we could design to take 2 5 v usb inputs, make it around 10v and then use a vv regulator? If you just use a Y-cable, you get double amps, not double volts... true? So, what circuit do we use?

Also note that conveniently there are 4 wires in a USB cable.....

Pumping 10V into a linear means a whole heat.

You didn't say what you want for your top vaping voltage.

 

[AttyPops]

Good point. Switched would be better then.

IDK.. since I don't do HV... but .... let's make it easy and say 7 / 7.5 volts. ( I assume that's easy).

It's really about voltage doubling. When I say "not use a booster" that means not using a whole module. I've seen some circuits that are pulsed that use caps. Some inductors. Many are for AC and rectify it. IDK if the dual input matters, other than there's plenty of amps. Kind of a trivia question for the technoids. Probably just easiest to use a boost module. Since that is essentially what it does... lotsa-amps + X-volts ->[boost module]-> less amps, more volts.

IDK if you could rig up a simple transformer (pulsed?) to do it, then smooth it out. Maybe that's kinda what the inductor does.

I think CraigHB built one, but IDK if it's less expensive. Anyway, Java_AZ's notes about the voltage drop above got me wondering if there's another way. There are dedicated IC's, no inductor. But they work in the mA range from what I've found so far. And we're using mains power here in our hypothetical PT, so efficiency is not as much of a concern as it would be with batteries (although your heat point is well made/taken).