I'm trying to use a portable power bank (5V/2.1A) and try to supply power to my DC/DC Converter which will then be used to power something else (probably a laptop or so). However, the issue is that with a load of 70W (in the case of a laptop), my input will need significantly higher current than just 2.1A (70W/5V=14A). Also, it seems like a 10W source from my port battery bank will not be able to supply enough wattage for a 70W load and hence my question.
However, the flexibility is that I do not need to supply a full load charge to the laptop and I just need to verify that this concept works and able to charge up a laptop even if it's a slow charge. On a side note, I need to feed the output of my DC/DC Converter to my laptop AC adapter. I'm using DC only because of SMPS-based adapters since rectification is the first stage.
Hence, I'm thinking if there are any current boosting techniques at the source side where I can use to amplify the 2.1A to a higher rating? I've heard of methods that is able to have a certain pulses of higher current (e.g. 5A) for an interval and a slightly lower current interval (e.g. 1A) and it averages it out to whatever the input can supply (e.g. 2.1A for my case). Not sure what is that called though. Anyone knows?
And what about darlington pair? Heard that transistors are used to obtain a higher current gain but not sure if this is applicable for my case as it seems to be used for small signal applications.
Any advice on this? Thanks!