PTN04050 Booster, need help! (Since i succed with the PTR08100 next...)

[bohoo]

I am struggling with this chip also

What i did: installed capacitors, switch and board. Then added a 100k pot between Vout and Adj and a 3A diode on Vout. This way i get between 4.6 and 4 V without load and have only an 0.2 voltage drop under load using a 2.0 Ohm ato. Using an 18650 battery.

So far so good.

But as soon as i add a resistance between Ground and Adj (in the specs it is marked as ''required") everything goes bananas. Even if i take out the pot and leave just that resistance it still wont go above 3.5V with load and makes some weird noise...

So my questions are:
Is the resistance between Ground and Adj really required?

How to get more the 4.x volts under load? As in the case where i put another 100k pot between Ground and Adj i can have any voltage without load, but as soon as i plug in the ato then it wont go above 3.5V

How to protect the switch also? Install a 10k res between Vin and Ground ? The switch is a simple push button installed on the ground wire before the chip.

Is the PTN protected against short circuits? As i understand it is not, but i think the diode is doing just that?! I want to make sure i dont burn it when i set up a genisis wick...

Cheers

PS: And oh yes, please excuse me if my questions are kinda dumb, but i started reading about electronics when i started this modding frenzy and it got me hooked up really good.

 

[jhonutz]

so between adj, out+ and GND you have a resistor divider for adjusting the voltage. It`s recuired both resistor, but one of this may be trimeror potentiometer for adjusting voltage

also PTN04050C don`t have short circuit protection..

 

[bohoo]

that is part of my issue. The resistor between Adj and Ground is not really required it seems - the PTN will default to the lowest output thus 5V. So it is fine as long as one needs only voltages under 5V.
But if i put both resistors hell breaks loose and i cant get more then 3.5V under load
I might be hitting the 12W limit with my 2.0 Ohm atomiser ?! but i have no ideea how to check that..

 

[asdaq]

Bohoo, you are killing the poor thing. Your 3.5v is full battery voltage minus the 3A diode so the board is straining to stay on (the noise) and just bypassing the boost circuitry. It is hard to tell as you are using a pot but one resistor is boosting above 5v (between 5.3 and 5.4 for 100k, lesser value and it is much higher) and then you are taking a fraction of this (closer to full than half, ~80-90%) and this can be calculated with Ohm's law to get watts. The diode stays out of this equation. Also you can measure the pot's resistance with a multimeter.

I just checked and with a 62K resistor and got 4.43v which is good for proax, much better than the diode option. A 100k resistor was less impressive, 4.6v.

 

[proax9]

...... I just checked and with a 62K resistor and got 4.43v which is good for proax, much better than the diode option. A 100k resistor was less impressive, 4.6v.

WOW- very much appreciated ASDAQ. I haven't rec'd all my parts yet, but hopefully I can breadboard this over the weekend.
Thanks again! (you gotta love the ECF "community")

 

[jhonutz]

that is part of my issue. The resistor between Adj and Ground is not really required it seems - the PTN will default to the lowest output thus 5V. So it is fine as long as one needs only voltages under 5V.
But if i put both resistors hell breaks loose and i cant get more then 3.5V under load
I might be hitting the 12W limit with my 2.0 Ohm atomiser ?! but i have no ideea how to check that..

Use a step down with 2xbatt, is the best way for VV.

 

[bohoo]

damn PC i just typed a huge message and it went away by itself

So again: Thanks all for the input

I had the feeling that i was killing the board but but... I dont know what else to do.
So is it ok to just use a pot between 3 and 4 if i want to get 4.2-4.4 V under load with a 2.0 Ohm atty? And leave no resistor between 3 and Ground. Like i was doing but i'm not sure if it is safe to run it like this.

If i want to go higher what else should i add ?

About the diode: I had the impression that a 3A diode will help protecting the board against higher currents, for example against shorts from the atomiser (using genisis atty). I got it all wrong ?! please clarify it for me.

Waiting eagerly for responses

yours electronics apprentice

 

[jhonutz]

if you put a diode to IN protect board of revers polarity only , diode in a circuit is not for higher current protection , use a reset fuse for protection

 

[bohoo]

see see how good i'm with electronics So the diode does nothing for me. I need to find a way to protect the board from high currents/shorts. My genisis atty tend to short out from time to time. Any thoughts? I dont know what a reset fuse is nor do i have one

 

[asdaq]

These are quite simple to add to a mod: flat ptc fuse - Google Search

With a genisis, a short tends to result in a very low resistance which hits the 4050's 12w limit. This causes the board to reset quickly and makes it whine. Under such conditions for a prolonged time, something will give and it is likely the short piece of kanthal that is taking the heat. I have found the 4050 to be quite tough, as opposed to the ego's mosfet which burns out quite easily.

But, those fuses are small, cheap, and simple to add so if you want to, go for it. (Assume all legal disclaimers here, safety first!)

 

[jhonutz]

yep flat ptc fuse, because @bohoo is from my country i will tell in our language, whit your permission off course , ....se numeste siguranta resetabila....you find this at Farnell.com

 

[jhonutz]

and link BOURNS|MF-MSMF200-2|MULTIFUSE, SMD, 1812, 2A | Farnell România for example, must buy for 3A 4 A 5 A and test to find something good for ptn04050C

 

[bohoo]

thank you all for the help provided. I finished it and it actually works
It will be inserted in my new tube mod.

 

[jhonutz]

a lot of work here .hard way with tub modd.i know very well that.

 

[asdaq]

a lot of work here .hard way with tub modd.i know very well that.

Nice job, the Kick available today of sorts. I see you squeezed the pot in there and it is hardly longer than the board, what resistor values and range are you getting?

 

[jhonutz]

not made by me , ask @bohoo about booster

 

[asdaq]

Oops, actually I quoted bohoo at first, cancelled , then quoted you-- no idea why. Sorry about that, it's been a day of unpleasant surprises.

 

[bohoo]

no probs

the pot is 100k, capacitors 100uf, and i left out all resistors. The pot is between pins 3 and 4. I get 3.3-4.7 V this way which is enough for me. Under load using 2.0 ohm atty it drops only about 0.2 V.

What made it a tiny bit longer then the board was those battery connectors. I tried damn hard to avoid that but i couldn't. Easy to slide into any tube and easy to take out.

 

[asdaq]

Nice. That makes for a compact solution too. Did you perhaps try a 200k? I haven't got any 147k fixed resistors at hand, but I suspect these would give something close to 4.8-4.9v.

 

[bohoo]

I didn't try. don't have anything above 100k, well if you don't count some 10meg ... It is surprisingly steady if i may say so.