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15 WATT REFERENCE DESIGN

Posted by: asabharwal on

I am looking forward to using this design as a float charger for charging a Lithium Ion battery and also running a DC load simultaneously. Battery charging Current shall be 1.0 Amp and balance 2.0 made available for the load. Please advise how current sensing be applied or which circuit path shall be current limited and which one will have no limit.
R9 is provided between chip GND and Earth. GND is indicated on the output terminal as well as pin no. 15 of the IC.
Conventionally I use current shunted load path for battery and without current shunted path for load.

Comments

Submitted by asabharwal on 11/09/2017

15 Watt reference design der 471 is being referred here.

Submitted by PI-DATA on 11/15/2017

You don't need current limit in DER471 as it will only provide what the load will draw as long as you don't overload the supply.

Submitted by asabharwal on 11/15/2017

Please read my query again, request proper answer

Submitted by PI-DATA on 11/15/2017

Hi,
Can you elaborate your query. Thanks.

Submitted by PI-DATA on 11/15/2017

If the load for charging and DC load is shunted, how will you manage to limit 1A and 2A to the other? I think the solution to that is to use multi-output power supply. In that way you can limit either or both charger and DC load.

If the output of DER471 is shunted to both battery and another load, it will just provide the power that is drawn as long as it is within the rated output power. It would be hard to limit only the other to 1A or vice versa as it will always give what it can. I mean, how could you limit the other or both load? If you have any solution please let us know.

Submitted by asabharwal on 11/15/2017

1.0 Amp for charging and 2.0 Amp for other load, what is the problem. I have no doubt about my concept. Please explain how it will be done in der471.

Submitted by PI-DATA on 11/15/2017

Hi Aabharwal,
There is no way you can split the load of DER 471 exactly to 1A and 2A. What you need to use is a multi-output power supply or you can use two DER 471 and adjust R9 to reduce the rated output current of the supply.

Submitted by asabharwal on 11/15/2017

Sir,
There can be two current paths. One through the shunt path and other bypassing the shunt. Shunted path shall be current limited.

Submitted by PI-DATA on 11/15/2017

Hi Asabharwal,
I'm not yet sure on how will you implement that in real life. Maybe you have a clearer way to do it and perhaps you can share your schematic.
Thanks.