Resister function

[VapingMike]

I am kind of lost on the function of the resistor. I mean, I know about electrical circuits and what resistors do in general, just not on my Prodigy. The switch that came with my Prodigy had a lump of solder on the brass contact for the battery, which was touching the resister lewd that should go to the switch. I clipped the extra solder and now that is fine, and the circuit has to go through the resister, but it hasn't made any difference. I am getting over 6 volts (usually around 6.5) on the adapter, so the resister is not limiting voltage to 5 volts as far as I can tell. I can meaure 50 ohms on the resister, so that's close to right.
I just don't know what the point of it is if I'm still getting the same voltage with or without the resister. If it's a question of only showing a difference with a load, I can test that if I absolutely *have* to, I just really want to make sure I am getting 5 volts instead of 6+. I have actually considered buying a resister like that and testing it on another mod to see if it gives me 5 volts, and if it doesn't, seeing what I would need to put in the circuit to make it 5, then adding that to my Prodigy switch (at least one of them).
I will be getting an unresistered switch in the mail tomorrow so I will be able to compare the two, but I'm guessing they will be the same voltage.

 

[TDM]

It drops to 5 volts once the circuit is completed by the atomizer. When it is ran with the atomizer the resistor knocks the voltage to 5v

 

[tparganos]

It drops to 5 volts once the circuit is completed by the atomizer. When it is ran with the atomizer the resistor knocks the voltage to 5v

How do you test the voltage on the resistor?

 

[VapingMike]

I tested resistance on the resistor, but that's the only way I know to test it. Is there a way to make sure it is dropping to 5 volt when the atomizer is running?

 

[VapingMike]

I did some research, and it seems like a zener diode or a voltage regulator would be a better choice to drop the voltage from 6+ down to 5v. I am thinking of getting one of these and adding it to a mod I made, just to test to see if I want to void the warranty on my Prodigy switch or not. Anyone with any experience with testing resistor voltage with a load, with voltage regulators, or with zener diodes please let me know any info you have, or anyone with anything about this - please - I can't help but obsess that I am still getting 6+ volts even with the resistored switch.
Thanks for your help!

 

[Flitzanu]

i'm an idiot with this stuff, but i can say, that if you are not testing it under load, it's never going to show 5v.

testing voltage on the adapter cap and ground on mine generally shows over 6v with the button pressed (with no atty) but that's not testing "under load."

i know there's a thread buried somewhere that explains how to do it, but it involves taking it apart and hooking it up some way that i don't know or understand i'm not an electronics expert, heh. but yes, the answer IS out there somewhere on how to test under load.

 

[VapingMike]

i know there's a thread buried somewhere that explains how to do it, but it involves taking it apart and hooking it up some way that i don't know or understand i'm not an electronics expert, heh. but yes, the answer IS out there somewhere on how to test under load.

Cool, as long as it's buried somewhere here, I'll look for it. This is driving me crazy. Thanks!

 

[tvujec]

i'm an idiot with this stuff, but i can say, that if you are not testing it under load, it's never going to show 5v.

There are complex voltmeters that can simulate the load. E.g. you could set internal voltmeter resistance to that of the atomizer (3.5 - 4.5 Ohm), and you would see the voltage drop. Common multimeters don't allow that, and will have internal multimeter resistance in MOhms if not GOhms to minimize the impact of the multimeter on the circuit.
Prodigy is actually rather simple to modify to be able to do under load measurements. Getting negative connection is easy, you can slightly unscrew the adapter or the battery cap, and attach the negative wire to the threads. For the positive (before or after resistor), you can use the hole on the prodigy body to connect the positive wire to the inside of the switch.

 

[Nuck]

Divide 6.0/(the resistance of the atomizer + resistance of the resistor) to get the current.

Multiply the current by the resistance of the atomizer.

That is the average voltage you're atomizer is receiving during a battery cycle.

 

[tvujec]

Divide 6.0/(the resistance of the atomizer + resistance of the resistor) to get the current.

Multiply the current by the resistance of the atomizer.

That is the average voltage you're atomizer is receiving during a battery cycle.

That is true, but it is still nominal voltage. Battery itself will drop voltage when under load, so you really have to measure that in a closed circuit. Lower the total resistance, bigger the voltage drop.

 

[CaSHMeRe]

I did some research, and it seems like a zener diode or a voltage regulator would be a better choice to drop the voltage from 6+ down to 5v. I am thinking of getting one of these and adding it to a mod I made, just to test to see if I want to void the warranty on my Prodigy switch or not. Anyone with any experience with testing resistor voltage with a load, with voltage regulators, or with zener diodes please let me know any info you have, or anyone with anything about this - please - I can't help but obsess that I am still getting 6+ volts even with the resistored switch.
Thanks for your help!

VM ... Voltage regulator gets too *hott* for my liking .... We tested roughly 30-40 different combinations/mixes until we found what I felt was a perfect median .... .5ohm 2watt resistor ... Under load, on a fresh set of batts, you are seeing roughly 5.1v ....

We even went as far as stringing zener/tvs diodes together to try and get the same effect, but nothing worked as well as the single resistor mentioned above.

There is actually a very simple way to test load -- outside of a prodigy .... perhaps ... I should call on my artistic skill in paint to show ya .... You will need some extra wire, a switch, resistor, and brass threading ...

 

[VapingMike]

VM ... Voltage regulator gets too *hott* for my liking .... We tested roughly 30-40 different combinations/mixes until we found what I felt was a perfect median .... .5ohm 2watt resistor ... Under load, on a fresh set of batts, you are seeing roughly 5.1v ....

We even went as far as stringing zener/tvs diodes together to try and get the same effect, but nothing worked as well as the single resistor mentioned above.

There is actually a very simple way to test load -- outside of a prodigy .... perhaps ... I should call on my artistic skill in paint to show ya .... You will need some extra wire, a switch, resistor, and brass threading ...

Cash - Yes - please whip up some kind of masterpiece to show me how to do it. I don't really want to drill a hole in my prodigy body to get the positive terminal in. I was going to take off the endcap and use a wire to connect the battery negative terminal to the body, then connect my multimeter. But if you have a way to do it outside the body that is easy, by all means, tell us.

tvujec - I wish I had a multimeter that would do that. Do you know of any specfic models that will? I want to try to pick one up. That would help me with many different projects (read - mods) I am working on. I didn't even know that those existed.d

Thanks to Nuck, tvujec, Cash, truckdrivingmouse & Flitzanu for helping me figure all this out. I have lots of experience with soldering and reading schmetics, but I've never designed my own and troubleshot on a component level before.

 

[CaSHMeRe]

VM ... you will be quite proud ... I was able to test within the prodigy ... Just whipped up a tool so it makes it easy Give me a couple minutes to upload!

 

[CaSHMeRe]

Alright ... Here we go ... How to test load

First -- Tools Needed
1) Prodigy (or any device for that matter)
2) Female Atomizer connector
3) Male Battery Connect
4) Wire
5) Multimeter
6) Perhaps an extra set of hands
7) Solder/Electrical tape

Batteries tested are the ones Casey uses day in and day out ... They are probably at about 70-75% fully charged.

Picture of equipment:

Picture of voltage tested at adapter (Non Complete Circuit/Not Under Load) -- 6.53V

Picture of completed Circuit (901 atomizer on the end). Testing Leads to check loaded voltage. -- 4.84v

Closeup, of exposed wires allowing you to put multimeter probes there to test.

Hope this helps people understand loads and test if they want to

 

[VapingMike]

Sweet - Thanks, Cash! I'm going to do this in just a little while. Great detail and photos - thanks again!

 

[Flitzanu]

hey Cash, arby's has sammiches on sale, 5 for $5, just in case you didn't notice.

 

[tvujec]

tvujec - I wish I had a multimeter that would do that. Do you know of any specfic models that will? I want to try to pick one up. That would help me with many different projects (read - mods) I am working on. I didn't even know that those existed.d

I had such device in a lab back in college. Since that was (very) long time ago, I went and googled a bit to find if there are such devices available for hobbyists. I managed to find some voltmeters that will allow load simulation for testing model airplane batteries, but load was fixed on all of them, so it wouldn't be usable. Other than that, only bench multimeters and some oscilloscopes had that functionality, and they can cost well over $1k.
If you're mainly looking at this as an e-cig hobbyist, you can hook up something similar to what Steve suggested. Only load you'll ever put on your battery comes from an atty, therefore atty is the best thing to test the load on. Otherwise, you should be able to find an affordable potentiometer with value display that will allow you to choose variable resistances for load testing.

 

[Mikie Likes It]

My 6 volt switch just stopped working. The wires turned black, and it will not work at all. Anyone else?

 

[VapingMike]

I will check into getting a petentionometer - wait, that is way too long, but you get the point. I did just now build a device like Steves and I love it - that will really come in handy! My voltage on my set of batteries that I had been using all day was 4.75 under load, and with a fresh set it was 5.45, but most of that over 5 was my fault for being too hasty with the center posts on the adapter. I will go back and fix them later.

I would think the black switch thing was caused by a short, probably a bad atomizer. Try a new atomizer and see if it works then. From what I understand, the resister is fine even if it looks burnt.