On the wiring of a TI ptn04050 voltage thingy

[Israfil]

I've finally got myself some nice little free samples from TI, and I'm trying to figure out how to wire these to work in my projects.

As far as I can tell, I wire pin 1 (gnd) to the negative side (where my momentary switch is, the atomizer, then the negative side of the battery.

I'm guessing based on their documentation that I wire pin 2 to the positive line from my batteries.

hmm....should have chosen electrical engineering as my major.

Anyone mind helping me make heads/tails of this?
http://focus.ti.com/lit/ds/symlink/ptn04050c.pdf
There are two pins that I don't understand the purpose of at all...

edit:I'm not sure how this thing is supposed to work at all, just that it's probably supposed to work. ^_^

 

[misterD]

dude. im no expert but i think you put the momentary switch before this booster. when im doing it it will be positive connection of the battery going to momentary switch pin. other "thingy pin" of switch to Vin booster pin. Vout booster "pin" to batt/atty connector inside positive. Ground booster "pin" to external side on batt/atty connector. the other "thingy" we dont care about cos it'd be if you wanted to boost to way above 5volts...

 

[candre23]

Are you just trying to get 5V from a 3.7V battery? If so, your wiring will look like this.

 

[WillyB]

There have been many posts centered around your thingy. Pics, diagrams, parts sources etc.

 

[UberDuper]

Don't worry about the capacitors. They aren't needed and take up a bunch of space.

I think I mentioned it before, but the 5v box mod I made using this booster is hotter then any other 5v or 6v mod I've used. If you're using ~2.2R atomizers you might want to add a diode between pin 4 and the atomizer to take the voltage down to ~4.3v.

UD.

 

[WillyB]

Don't worry about the capacitors. They aren't needed and take up a bunch of space.


UD.

I guess a car would run with an air filter also.


From one of Nuck's posts:

One thing though, the caps are extremely cheap and easy to install and there is a world of difference if you add them. The bat will last longer per charge and you will save on the life of the battery. Without them you are forcing the bat to pulse nonstop well above its threshold for damage (about 4C). Highly recommended.

 

[UberDuper]

That sounds silly.

UD.

 

[5cardstud]

Are you just trying to get 5V from a 3.7V battery? If so, your wiring will look like this.

Thank you candre23. You are the man.

 

[misterD]

have a link for those ELECTROLITIC 100? they seam to be huge!!!
and that other required "thingy" going through pin 1 to pin 3. please

 

[candre23]

I wouldn't call them "huge". 5mmx5.4mm SMT or 4.5mmx10mm axial. The "thingie" between pins 1 and 3 is a resistor used to set the output voltage. Since the device defaults to 5V with no resistor, and that is the desired output, I removed it from the sketch.

 

[misterD]

thanks, candre!! i presume we can make without it them! this thingie is getting harder and harder with no blue pill. (i know im not funny)

 

[WillyB]

have a link for those ELECTROLITIC 100? they seam to be huge!!!
and that other required "thingy" going through pin 1 to pin 3. please

Nothing needed for 5V operation.

The adjustment range is from 5 V to 15 V. If pin 3 is left open, the output voltage defaults to the lowest value.

Well Nuck (a perfectionist) recommends LOESR caps.

Digi-Key - 495-1529-1-ND (Manufacturer - B45197A2107K409)

 

[Israfil]

Are you just trying to get 5V from a 3.7V battery? If so, your wiring will look like this.

Thanks the schematic helped alot! I'm still no closer to understanding how it works, but I'm happy with the simple fact that it DOES work.

Edit: seeing as so many people use these boards for 5v conversion, shouldn't there be a sticky (preferably of that nifty schematic) to assist future modders?

 

[Israfil]

Just thought of something...since this operates over a range of voltages and brings em up to 5v, wouldn't it somewhat fix the voltage drop over the life of alkaline batteries? Just an interesting thought...Was thinking that it'd operate up until the voltage fell below the ability of the chip to function and then wouldn't work.

 

[Global_Apathy]

Israfil, That is why you choose a boost regulator with a cutoff voltage about where you are supposed to stop drawing on a Li Ion battery. It will keep you from discharging them past the level the protection circuit operates.

 

[Israfil]

Hadn't even thought of that nifty little bit of info...nice Apathy

 

[Nuck]

Israfil, That is why you choose a boost regulator with a cutoff voltage about where you are supposed to stop drawing on a Li Ion battery. It will keep you from discharging them past the level the protection circuit operates.

Easier to just put the protection on the battery.

 

[candre23]

If you cut off the battery before they get low enough to trip the built-in protection, they'll last a lot longer. The built-in limits are only supposed to be an emergency safety feature, not a replacement for proper charging and discharging practices.

 

[Nuck]

If you cut off the battery before they get low enough to trip the built-in protection, they'll last a lot longer. The built-in limits are only supposed to be an emergency safety feature, not a replacement for proper charging and discharging practices.

The cutoff for over discharge isn't an emergency feature on a battery protection circuit. Its the same thing you would have to add to any boost Ive ever seen to ensure proper operation. If you wanted to double up on it, then go ahead but since the boost in question will start to hum long before the cutoff takes place it's a non-issue.

 

[Global_Apathy]

To me it's just quality in engineering. If you are going to spend the time to design a circuit for a specific function, make sure all aspects are covered. The protection in the battery may not always work. Someone may put an unprotected battery in it.

I know there are functionality issues as well. You don't want to lose power when you don't need to and you want the battery to last as long as possible. For the kind of current and voltage you want large capacitors and inductors will be required to sustain the current across the load without damaging the battery. Since the load is inductive one should use a zener to prolong the life of the coil.

I don't know if anyone here has experience with relay based control systems but coils are coils and current stored in the coil causes bad things to happen if it is not dissipated properly.

You also have to make sure that the battery's internal resistance is such that it can supply enough current for the circuit, this should be an output specification of the battery. If you are going to boost the voltage and want to sustain voltage and current over the load the draw on the battery will definitely increase. These boost regulators pulse the output which lowers the current necessary... but your batteries will die faster.

All in all I just like to cover all the bases.