Re: Power supply
Posted: Sat Mar 17, 2018 1:41 pm
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rudy wrote:It is a step up (boost) converter. I thought you were going to be using batteries as a backup supply to the AC powered 5 volt supply. I thought you wanted this converter to make the battery voltage higher. If you want a converter to take 5 volts and produce 3.3 volts then this is not the right converter.
Normally the power source (before conversion) will be higher than the required voltage (called a buck converter), or lower than the required voltage (called a boost converter. There are some chips that are designed to allow for a lower or a higher input voltage compared to the desired output (called buck-boost). They are more complicated.
http://www.learnabout-electronics.org/PSU/psu33.php
I have taken a simpler approach on some of my projects. Because I wanted 5 volts for a character LCD, or other devices, I used a boost regulator to take the power from a lithium 18650 battery to generate the 5 volts, then for the 3.3 volts required by the ESP8266 I used a linear regulator.
This is not a efficient use of power but it is sufficient for much of my needs. I have a USB to lithium battery charger to charge the battery and it also powers the device when I need it to run continuously.
I have been using this at work as a data logger for the last two months.
This is the pair of boards I have used together with a 18650 lithium battery. I remove the large USB connector on the boost converter.