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Getting a led to turn on when voltage is under 3 volts on a battery
- Thread starter Juvoal
- Start date
Arouse1973
Adam
Hello Juvoal. Have a look at a comparator. You will find lots of low voltage alarm circuits on the net.
Thanks
Adam
Thanks
Adam
Bong!!
This circuit flashes when the voltage drops to 4v. The voltage "set-point" can be adjusted by changing the 150k on the base of the first transistor.
hevans1944
Hop - AC8NS
It's box mod (for modification), not box mode. A fairly recent description of vaping can be found here. The box-type power units are a favorite of "cloud chasers" because they are capable of driving a very low resistance atomizer coil, usually a drip coil, to produce copious amounts of vapor.
I use one of these box-type battery power supplies, backed up by a more traditional cylindrical battery power supply. Both have sophisticated electronics inside to safely discharge and charge high current-density lithium ion batteries. My box-mod is made by Eleaf and is called an IStick TC40W. It and the cylindrical battery power supply are used interchangeably with a Nautilus Aspire atomizer tank.
The IStick features either power control up to 40 watts or temperature control if using nickel coils. I use it at 7.5 watts with kanthal coils. It has a blue OLED display that shows the amount of battery charge remaining, the battery voltage, the coil resistance and the power setting. After pressing a button to turn on the coil it keeps track of how long it was turned on and displays that too. It runs most of the day on one charge and re-charges overnight in about three hours.
Unfortunately, all those features make the IStick a little pricey. So, some people prefer to "roll their own" power units. These are the same people who wind their own coils and build their own atomizers and tanks, a practice known as moding a vape. In other words you start with a commercial product and make modifications to customize it to your own taste, sort of like building a hot rod automobile in the 1960s but much less expensive. And much more dangerous since most of these moders don't know squat about the dangers associated with charging and high-current discharging lithium ion batteries.
I may know some squat, but I prefer to purchase a manufactured product and forego the risk of a lithium ion battery blowing up in my face or melting in my hand. My battery box mod simply quits producing vapor when the voltage gets too low. That's when I know it is time to swap it out with the cylindrical battery power supply and put the box mod on the charger overnight. Even then, I charge it in a glass jar just in case an "accident" should happen.
So, try @Colin Mitchell 's circuit or purchase a low-voltage comparator and try to roll your own. But why would you want to run the battery down any further with a blinking LED? Just turn it off, like my IStick does. The user will definitely notice when it fails to operate.
Hop
