Just For LM2596 Users

[Dothan]

These are tiny....





Mini Size 3A 4 5 28V Input 0 8 20V Output Step Down Voltage Regulator I | eBay

I got my chips yesterday, I bread boarded them, the pot was weird, but I went ahead and did a test build... I put them in a Snus tin with 2 14500 batteries. took a tip from way early in this thread, cut short section one of the wife's manicure sicks, glued it to the pot, then coated with rubber to look decent.. that goes through the back of the tin for adjusting. it vapes every bit as good as any of my lm builds, except that the pot sucks... it jumps high and low turning the same direction! I was seeing 7.2, twist just a hair, 3.3 twist a hair more and 7.0... very frustrating have you had issues with it? looks extremely small to try d-soldering and putting a decent pot in it's place... any thoughts would be great!

 

[chuckie]

Got 2 of them.1 works ok,the other one is a piece of junk.It acts about the same as yours.I'd use to okr t6 or t10 instead.

 

[Visus]

Two boards you guys might be interested in the prices are great with free shipping included..

Step up Booster
LM2577S DC-DC Adjustable Step-up Power Supply Module - Free Shipping

Step Down Buck
http://www.satistronics.com/mp2307dn-3a-dcdc-stepdown-power-supply-module-kis3r33s_p2798.html

 

[Artifex75]

Hello,
I picked up an LM2596 from eBay with some nifty bells and whistles for my first vv mod. Here's the link:

DC 4 5 28V to 1 3V 25V LM2596 Adjustable Buck Step Down Converter LED Voltmeter | eBay

However, I have no idea what the "work status interface" is. Little help from the LM2596 gurus before I mess it up?

 

[Quigsworth]

w
Work status interface?

Sent using a soup can and a piece of string

 

[Artifex75]

Yup.

 

[BeerBandit]

i read through this whole thread the other day, but i must have forgot to save pics... im sure there has been at lease one schematic drawing of how to make your own lm2596 circuit, right? if anyone happens to know which pages i might find some schematics at, would you kindly point me in the right direction? i really dont feel like going through the thread allll over again

 

[SupplyDaddy]

Just got the board Artifex75 posted about (Post #1084 and #1086). Like the setup for it.. Will be desoldering the LED display so I can put it all in my Hammond box the way I want it, and rerouting the button switch to a remote tact switch (again, to put it in easy reach for me...) and was thinking about doing the same to the Potentiometer, when a thought occurred.. (yes, it hurt, just a little...)

(This might apply to all the LM2596 boards..)
Can I switch out the 3296 potentiometer, on a 1 for 1 basis with this? 91AR200LF BI Technologies / TT electronics | Mouser
its 200 Ohms, 500 mW (1/2 W). IfF I can, can I just simply plug and play or am I going to have to add resistors and such to do so?
Figure that trimmer would be easier to work with than the one on the board, and I do have the setups to mount that in a way that works much easier for me (8mm LED mount).

 

[ut1205]

Just got the board Artifex75 posted about (Post #1084 and #1086). Like the setup for it.. Will be desoldering the LED display so I can put it all in my Hammond box the way I want it, and rerouting the button switch to a remote tact switch (again, to put it in easy reach for me...) and was thinking about doing the same to the Potentiometer, when a thought occurred.. (yes, it hurt, just a little...)

(This might apply to all the LM2596 boards..)
Can I switch out the 3296 potentiometer, on a 1 for 1 basis with this? 91AR200LF BI Technologies / TT electronics | Mouser
its 200 Ohms, 500 mW (1/2 W). IfF I can, can I just simply plug and play or am I going to have to add resistors and such to do so?
Figure that trimmer would be easier to work with than the one on the board, and I do have the setups to mount that in a way that works much easier for me (8mm LED mount).

Someone correct me if I am wrong, but I believe the blue pot on the board is 10K ohms. You need to stay close to that value.

I built a mod powered by a 19 volt laptop power supply and changed out the blue pot with a 2K ohm pot. My range of voltage is pretty much "off" for the low side to a max of 5.5 volts on the high side.

 

[SupplyDaddy]

I found a version for 10K ohms. 91ER10KLF BI Technologies / TT electronics | Mouser

 

[SupplyDaddy]

I found a version for 10K ohms. 91ER10KLF BI Technologies / TT electronics | Mouser

I find this trimmer is just too sensitive for the board. Less than a quarter of a turn takes it past a usable range and my fat fingers just can't keep the faction of a turn needed small enough LOL
Going to have to try the 200 ohm version.

 

[BJ43]

10k pots I use.

PT10MV10-103A2020 Piher | Mouser

PT10MH01-103A2020 Piher | Mouser

Knob for PT-10

JPEPL5012NE Piher | Mouser

 

[SupplyDaddy]

10k pots I use.

PT10MV10-103A2020 Piher | Mouser

PT10MH01-103A2020 Piher | Mouser

Knob for PT-10

JPEPL5012NE Piher | Mouser

Thanks BJ, got those now on my future list. Just going to run with the setup I created for now. A learning experience. At least this thing vapes pretty well!!

 

[ut1205]

I find this trimmer is just too sensitive for the board. Less than a quarter of a turn takes it past a usable range and my fat fingers just can't keep the faction of a turn needed small enough LOL
Going to have to try the 200 ohm version.

Just to review my experience changing the pot.

I am using a laptop power supply that puts out 19 volts DC.

With the original (blue) pot that came on the board I was able to obtain "0" to "16+" volts DC. The blue pot is around a 25 turn so volts per turn was reasonable.

I change the pot to a 2K one turn pot. Voltage available dropped to "0" volts to "5.5" volts DC but became very "touchy" and somewhat hard to set (probably as a result of going from 25 turns to one turn). I used this pot:

2K OHM Linear Taper Potentiometer Round Shaft PCB 9mm

Based on my experience, lowering the value of the pot just reduces the high end of your voltage (I went from 16+ to 5.5). I think the secret to smooth voltage selection is a "multiple turn" pot and I haven't seen one of them with a thumb wheel. With 200 ohms you may not get any voltage at all.

If you try the 200 ohm, post back. I am interested to know the results.

 

[ut1205]

I find this trimmer is just too sensitive for the board. Less than a quarter of a turn takes it past a usable range and my fat fingers just can't keep the faction of a turn needed small enough LOL
Going to have to try the 200 ohm version.

Ok, curiosity got the best of me. I have several spare LM2596's so I decided to experiment with various pots.

I used my power supply and set the input voltage to the LM2596 to 8 VDC. This voltage stays constant through all the tests. The reason I chose 8 volts is that it is pretty close to the voltage of two 18650 batteries wired in series. Results are:

Ohms, Low Volts, High Volts
10K 2.0 7.9
5K 2.0 7.6
2K 1.3 5.5
1k 1.3 4.7
500 1.3 2.7

I intended to go lower but 500 ohms was the lowest pot that I had. This does prove what I thought that a reduction in ohms just lowers the "High" voltage. I have gotten use to the adjustments and 2K ohms works for me.

Hope this helps with your "build".

Edit: My chart looked good until I posted it.

 

[BJ43]

Ohms, Low Volts, High Volts
10K 2.0 7.9
5K 2.0 7.6

Surprised you can get 7.9 or 7.6v with an 8v input. All LM2596 I have tested and used for years need at least 2 more volts at input than the output. If I go with 8v input on mine, the highest output I get is 5.5 to 6v. I use 12v lipo packs on mine and 12v power sources on my passthrus.

 

[ut1205]

Surprised you can get 7.9 or 7.6v with an 8v input. All LM2596 I have tested and used for years need at least 2 more volts at input than the output. If I go with 8v input on mine, the highest output I get is 5.5 to 6v. I use 12v lipo packs on mine and 12v power sources on my passthrus.

That kind of surprised me also. Of course, these are "no load" values. If you put an amp or two load on it it would probably drop some. I built one that uses two 18650 batteries and a 2K ohm pot and the most I can get out of it is 5.5 volts but I don't know if that is because of the pot or voltage drop in the 2569.

I'm working on another project that requires 5 volts DC and I have a couple of transformers that after rectification give me 6.5 VDC. With a 7905 regulator it drops to 4.5 volts. Guess I will have to use them on some 3.3 volt project.

 

[SupplyDaddy]

Finally finished my last LM2596 project. Plan to do this again!

Hammond 1590B box, stone coated, removed and relocated the 10K pot with a 10K trimmer in an 8mm LED mounting to the opposite side from the fire button, ego connection on top

Tact switch for the voltmeter, I can make adjustments without firing the device, and although thing is large, no light is shown when fired for stealth. Using the tact when firing does pretty good on showing the power drop.

 

[Thelonious]

I am still confused on the pin hole on/off switch.

If it is left open and people are firing, with lets say a 3A switch on the Vout. Would it not continue to fire if I have a n/o switch through the pin holes, and no switch on the Vout? Now it would make sense if people are having to jump the pin holes in order to add a Vout switch, but that is not what I am getting from this.

 

[RAMartinJr]

Hello,

I am building a VV box mod using the LM2596 board power by two 14500's in series. I would like to be able to charge the batteries in the mod, can two USB charger boards be hooked up one to each battery while they are in series?

You could remove the USB connecter from one board and tie the inputs together and then wire each boards output to one battery.