Drok boost converter into sepic

Thread Starter

Redride27

Joined Mar 14, 2016
2
I have a DROK boost converter that I was wondering if I can modify into a septic design. When powered off I'm still seeing voltage at the output. I now know that this is due to the boost converters design. It uses a Texas instruments c2803 controller . 20190820_074205.jpg 20190820_074213.jpg
 

RPLaJeunesse

Joined Jul 29, 2018
254
SEPIC converters typically use a dual winding, so the inductor needs to be replaced with one having the same inductance (per winding) and the same current rating. With twice as much copper wire on it expect it to be bigger than what's presently there. A winding-to-winding capacitor is needed, the value of which is determined by frequency, current, Vin & Vout ranges, max temperature, etc. The dual inductor will have leakage inductance, so the driver transistor needs to be protected for its effects. Adding a relay in front of the converter would be much simpler...
 

Thread Starter

Redride27

Joined Mar 14, 2016
2
Hey thanks! Yes I meant to type sepic converter but my auto-correct did its thing. I'm mostly looking for a way to decouple the load when the unit isn't in boost mode. When adjusting the voltage and current I still need power to the unit. A relay or mosfet on the output would work perfectly.
 
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