Need a 16.1V buck boost anyone have a circuit?

[terramir]

I posted this in another part of the forum and I'm not getting any responses which probably means this is where this question belongs
I need to build a 16.1V buck boost That can handle a Voltage input anywhere from 18.5 to 9 V and current anywhere from 100 mA to 7A
is this possible to make with high efficency?
Let me know if you have a circuit
terramir

 

[TillEulenspiegel]

Ok let me take a stab at the problem.

First off the nomenclature of a "buck-boost" normally means a transformer which is used to boost V because of V sag over wire length .
What Your asking is for a buck boost converter . What that entails is quite more complicated then any ole' transformer.

The process that you need is one that includes regulation at input , so you won't over V the circuit. The second part is a boost converter that uses inductors to supply the "missing" V, the out of which is negative.
You must employ a smart Voltage sense which monitors V and tracks Input V-C

The last stage is a VR that can supply a V down to a few mV.

Finally to your A limits Is this the draw or the supply? Details are scarce here , perhaps if you explain what your attempting to do , it would be more helpful It appears Your trying to build a platypus.

The answer to Your question about efficiency is--no , any time you go through multiple stages of conversion ( especially utilizing transformers) the efficiency goes downhill.

 

[Russlk]

This URL may give you some info: https://www.linear.com/ezone/1625.html

 

[terramir]

well this is the deal
well the inputs are multiple solarpanels, they go from 17-18 V high to as low as 14 volts before the light get's so bad it's not worth it mA wise anyway.
But the voltage in direct sunlight is about 18 to 18.5 in diffuse sunlight depending on brightness 16.8 to 14.5 and then at dusk it drops down to nine volts and like 20 mA (so that's not worth it)
What I need is a percision controller that will regulate the voltage to exactly 16.1V no matter where the voltage lies at any given time and shuts off when the current goes below a certain treshold.
help
terramir

 

[k7elp60]

I would go buy a solar charge controller. Trace engineering is one manufacturer. I had one installed to charge 12V batteries. You can generally select the charge voltage etc. Mine would start to charge when the voltage from the solar panels was a few tens of a volt above the battery voltage. The interesting thing was the solar panels produced voltage when it was light and the sun was not directly on them. When the
sun was on them they really produced voltage and current.