1st VV Mod Low Output Voltage...PLEASE HELP

[brugmanncues]

OK, I tried putting together my 1st VV mod and used the poorvari schematic and followed it exactly with the exception of adding a 3 wire LED voltmeter. Used the same resistors, trimmer pot, LED, 2 Ultrafire 14500s in series, 3A fire switch, 3A master switch, 510 connector, lm350t IC and 20 ga. hookup wire.

All I'm getting out of it is reading 3.0V, it does adjust but the range is 0.0V - 3.0V

I'm completely baffled on this! Can anyone please help or any suggestions?

Here's the schematic I used:



Thanks everyone,

Nathan Brugmann

 

[been there]

Hey brugmanncues in your second schematic it's calling for 8 volts and you are using 14500 in series which gives you 7.4 volts I think your lm350t might be under powered hope this is right,haven't done any moding in a while a little rusty.

 

[brugmanncues]

I was curious about that myself. But just about every other poorvari mod I've read on here has been using the 2 14500 ultrafires. Maybe they just rounded up the voltage of the 2 in series? Not sure. The lm350t has a minimum input of: 4.2V So I would think 7.4V would be plenty to power it.

 

[been there]

Your right if the input is 4.2 but why does the second schematic show a 8 volt source? and if I were you I would use your volt meter and check you solder joints to see if you have a bad joint.

 

[pianman6954]

I can't seem to find the DO for this particular regulator, I noticed no cap to curb transient response. Are these voltages under load? Also probably check your resistors, its good to make sure your not mistaking a tolerence band for a multiplier or vice versa. My first regulated mod was a flop because I did all of the research on the regulator except the dropout voltage so under load it only worked well up to about 4v which promptly oblitterated my dual coil carto .

 

[asdaq]

Something is amiss with solder joints or the resistors as you have an inaccurate resistance value in the r2. This value and it's function is in post 25 of the original thread. I think it is 25.

Sent from my Nexus 4 using Tapatalk 4

 

[WarHawk-AVG]

Double check the resistance of your potentiometer

 

[brugmanncues]

I appreciate all the responses and after going back and doing a lot of these suggestions and more reading....looks like it was either a bad solder, or I had the 3 wire led voltmeter measure wire in the wrong spot lol gotta love us newbs

Thanks again everyone!!!

Nathan Brugmann

 

[WarHawk-AVG]

I appreciate all the responses and after going back and doing a lot of these suggestions and more reading....looks like it was either a bad solder, or I had the 3 wire led voltmeter measure wire in the wrong spot lol gotta love us newbs

Thanks again everyone!!!

Nathan Brugmann

You got it running?

Poorvari? Pics or it didn't happen

Good job!

 

[brugmanncues]

I have it wired together, not in the case yet. Working on that when I have time. Going to be an Altoids tin. So far I have coated the inside with liquid electrical tape, and installed the atty connector, fire switch, red led and epoxied the battery holder in. Have the pot, led voltmeter display, lm350t, and the main switch left to cram in there lol

I'll post pics when its up and running