Mod Voltage Wisdom Sought

[Cool_Breeze]

I built my mod not long after starting vaping. It is based on the Rev. 2 VV kit from madvapes. That contains a NCP630A 3 Amp Adjustable Regulator. It is powered by a pair of 18350s in series yielding a supply of 7.4 volts.

Recently the chip went out on it. It was frustrating in that is showed appropriate voltage at the connector but wouldn't fire a carto. I finally deduced it wouldn't carry a load.

I ordered a replacement and installed it. All was fine...for about a week. The replacement went out as well and showed the same characteristic voltage at the battery connection.

I've read that regulators (or is it a buck in this case?) are much less efficeint at low output voltage. I notice the output voltage was set in the 4 volt range...perhaps lower.

Is the low setting a likely source of chip failure? If so, what's an appropriate minimum low voltage to use with the 7.2 Volt input?

 

[CapeCAD]

According to the datasheet these devices appear more than capable of supplying the lower voltage with the proper 68uF input cap and 33uF output cap up to 3 Amps.

If you are still measuring the proper output voltage it is more likely that the device is working fine and there is something else wrong, perhaps corroded connections, causing the drop in output current.

Things to check are:
Make sure center post of atty connector is making good contact
Make sure there is a good solder joint on all connections
Make sure switch is making a good solid connection

 

[Cool_Breeze]

CapeCAD - lol...I just assembled the board according to some user generated diagram I found in related information. No caps were shown there. I've got the datasheet. I may have the proper electrolytic caps in my collection.

Thanks.

 

[TomCatt]

Any new info on your mod, Cool?

 

[Cool_Breeze]

Hi TomCatt. I went ahead and installed the capactiors. As expcected, it did not ressurect the chip. I ordered two new chips and expect them tomorrow.

 

[TomCatt]

If at first you don't succeed, mod and mod again

Good luck Cool!

 

[breaktru]

I've fried a few myself Cool during the tweaking phase.

 

[Cool_Breeze]

Looks as if they'll be arriving tomorrow (Thursday).