My definitive sweet spot is 4.2 with LR. Yes, I know I can use 5v with a HR but I prefer the former. So for all you tech gurus out there..is there a way to modify say this regulator LDO 5 volt, 3.0 amp regulator with control pin! by adding resistance or something to get regulated 4.2 out of it?
Convert a 5v regulator to 4.2v?
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If you put a single diode on the voltage out side, it will drop the voltage to about 4.3-4.4. Once you take into acount the load, it should be pretty much dead on.
If you add a 3A barrel diode between v-out and the atty, it will take the voltage down IIRC .6v
But, you could take pretty much your choice of VV chips and add a resistor to set the voltage you want and it can be efficient too. Your example regulator with a diode wastes the unused voltage quite heavily.
But, you could take pretty much your choice of VV chips and add a resistor to set the voltage you want and it can be efficient too. Your example regulator with a diode wastes the unused voltage quite heavily.
The OKR-T is pretty small, and those diodes are big with thick leads. How small is your space?
Just think of the extra vaping time you would get with a more efficient regulator, 4.2 volts out with 7.4 in.
(90% instead of 56%)
Here's one set up for fixed voltage.
The murata OK-R is pretty small
3 amp one in first photo, 6 amp in the second photo.
(90% instead of 56%)
Here's one set up for fixed voltage.
The murata OK-R is pretty small
3 amp one in first photo, 6 amp in the second photo.
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+1 on a VV chip with a resistor instead of a pot for fixed voltage. You should get a lot more battery life.
Some use a main switch between battery and input pin but a low current switch can be used on control pin. I use a 3300 ohm pull down resistor from control pin to ground pin. For variable voltage I use a 100 ohm pot in series with a 330 ohm resistor for a total of 330 to 430 ohms. Schematic shows wiring for low current tach switch.
Digikey for the murata, 50 cent pot, and a couple of 10 cent resistors, 2 or 3 bucks for first class shipping.
Digikey for the murata, 50 cent pot, and a couple of 10 cent resistors, 2 or 3 bucks for first class shipping.
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Do you know if connecting control pin to Vin will damage the converter?
The spec sheet says no problem.
What I found was the pull down resistor has to get the control pin source to less than 0.4 volts to reliably switch.
With 12 volts (car pass thru) and 8 volts (stacked cells) 10 k did not pull it under 0.4 volts. 3 to 5K did.
I am using the OKR-T/3-W12-C and T/6
not the OKR T/3-W12-EC, pull up pull down works differently
What I found was the pull down resistor has to get the control pin source to less than 0.4 volts to reliably switch.
With 12 volts (car pass thru) and 8 volts (stacked cells) 10 k did not pull it under 0.4 volts. 3 to 5K did.
I am using the OKR-T/3-W12-C and T/6
not the OKR T/3-W12-EC, pull up pull down works differently
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Thanks.
I just took a look at data sheet and it has info for connecting to control pin to voltages up to Vin.
Cool.
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