voltage regulator selection

Thread Starter

dcd528

Joined Jul 28, 2011
46
I have a circuit which powers a heating coil from a Li ion 18650 battery, 3.7V 20 A. I want to use the battery to power a microchip which in turn controls a MOSFET that turns the coil on and off.
I thought I could just tap the battery and the voltage regulator would only use the current it needed. The design works for a bit then the voltage regulator gets fried.
There is a voltage divider which I plan to use to monitor battery voltage but I haven't tested that, the caps on the voltage regulator are 0.1uF
Please ignore the pin out on the microchip, the voltage divider is an input to the microchip and the connection to the MOSFET is an output to bias the MOSFET.
So my question is how can I power the microchip and the Load in this circuit.
My apologies if the diagram or my explanation are lacking, I'm happy to add any info that is needed.
thanks
 

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Thread Starter

dcd528

Joined Jul 28, 2011
46
AP2111H-3.3TRG1 3.3v 600 ma. The MOSFET is STD150N3LLH6 30V 80A
The battery is nominal 3.7 V but at full charge is 4.2 V, the coil can draw up to 10 A
 

Thread Starter

dcd528

Joined Jul 28, 2011
46
Try installing a ferrite bead inductor between the battery and the input of the regulator.
Can you suggest the specs for the ferrite bead? I am not familiar with them and looked it up and the specs could involve impedance@frequency, current rating and dc resistance.
thanks for your suggestion
 

Thread Starter

dcd528

Joined Jul 28, 2011
46
Do you have old electronic boards laying around? Salvage one of an old board.
They look like this:

View attachment 212699
yep I looked them up, I would just as soon buy a new one they are really cheap and I am still getting odds and ends.
but when I looked them up I wasn't sure what kind of ratings I should go for, especially the amps. Any tips?
 
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