4050 booster question

[DonG]

Can the switch be placed on the negative side of the board? So far diagrams I have been looking at are all positive side switched. The mod I want to add this chip to is already negative switched.

Edit. Also if the control pin is left blank will I get 5v and adding the resistor is just to alter the output; or is the resistor required?

 

[Java_Az]

Can the switch be placed on the negative side of the board? So far diagrams I have been looking at are all positive side switched. The mod I want to add this chip to is already negative switched.

Edit. Also if the control pin is left blank will I get 5v and adding the resistor is just to alter the output; or is the resistor required?

You should have no problems putting the switch on the ground. The ground just has to be isolated which it should be if the old mod used the ground to switch.

the voltage set resistor goes from pin 1 to pin 3 . If left open or putting no resistor in the reg will put out 5 volts. so you got that right no resistor is required if you just want a 5 volt booster.

 

[DonG]

Thanks Java.

This is what I have laid out. Seems I saw a list of resistor values for various output voltages too but can't find it now. If someone has a link to that info please post.

 

[Java_Az]

That will work but your switch is not going to last long. Those tactile's cant handle the amperage needed to vape. Adding a N channel mosfet would solve the problem or a bigger switch that is rated a lot higher to handle the amps.

here is the resistor chart from the Data Sheet

 

[asdaq]

Page 9 of the spec sheet has a list of the values for voltages above 5v, as Java described above, or if you place a resistor between 3 & 4, you can get these values:

5.0v - OPEN
4.6v - 100k
4.57v - 82k
4.43v - 62k

More I haven't tried, but jhonutz put a 100k pot here and gets 4.3-4.8v I believe. One thing, those caps and that switch look rather light for the job. An IMR 18350 would work better too, this board likes the current.

 

[DonG]

Thanks for the feedback guys. Switch is for illustrative purposes only to confirm my new layout; the mod being used has a full mechanical switch.

 

[asdaq]

Ahh OK, we were being gentle about that.

 

[DonG]

Well, got everything soldered up nice and neat. Tested with my "bench battery". 3.9v input; 4.95v output with control pin open. Vapes clouds. There is a slight audible noise from the booster; not even as noticeable as the crackle of the atty ; is this normal? Ready to start installation but don't want to ruin it.

 

[asdaq]

That would be the sound as it is starved for current. What is the bench battery?

 

[DonG]

18650 with a 510 connector. Did not solder my board leads to test; just twisted. So probably just a loose connection. So I should have no noise when operating correctly?

U said starved for current so I guess that could be either low input or too much draw on output correct? Just checked the test atty to be 2.0 ohm.

 

[asdaq]

Kinda hard to tell, but could well be a combination of the two. The whine is the 4050 hitting a limit and resetting itself quick enough to be heard. With a good setup it wouldn't do it until the battery gets low and then it is an indicator to charge.

 

[Java_Az]

mine doesn't make any noise at all. But i have electrolytic caps on my setup. looks like you have ceramic caps in your picture. ceramics are good at filtering low frequency noise but not good at the higher frequency. The data sheet on the boosters say it requires electrolytic caps on the input and output. Some folks have used tantalum caps in place of the electrolytic as they are better then ceramics at filtering the higher frequency noise and come in a smaller package size

 

[DonG]

I only ran a 60uf on the input side thinking it just served to stabilize power. I will bump it up and see how it does.

 

[DonG]

OK. Thanks again. Bumped both caps to 150uf and working good. Did not quite get my tube small enough. Goal was direct replacement of an18650 with the booster and 18350 but my module ended up a little long. Have to get it a little shorter. Does fit with a 16340 though so at least I can enjoy my first 4.99v mod a little.

 

[Java_Az]

Not sure if this will help or not but i use these caps. They are pretty small RNE1C101MDS1PX Nichicon Aluminum Organic Polymer Capacitors