Battery Pack: Techniques to Disconnect Output when Input is Present

[ngmedaboard]

I am designing a battery pack with an integrated charger and boost circuit for the output. I need to cut the power to the boost circuit whenever an input voltage is present to prevent pass through.

The following is a simplified block out of my system, suggestions are greatly appreciated on the cutoff portion.



Thank you

 

[BradtheRad]

You may or may not find that a mosfet (probably a P-mos) can turn on and off properly, depending on whether the gate can see a definite reference voltage on the necessary terminal.

A relay may end up being the most convenient option.

 

[keith1200rs]

I am not sure if it will do what you want but the Linear Technology "Ideal diodes" may be worth looking at. https://www.linear.com/products/PowerPath_Controllers_*_Ideal_Diodes

Keith

 

[ngmedaboard]

I am not sure if it will do what you want but the Linear Technology "Ideal diodes" may be worth looking at. https://www.linear.com/products/PowerPath_Controllers_*_Ideal_Diodes

Keith

Hi Keith,

I may use the ideal diodes elsewhere in my circuit, recently became aware of them. But I'm not sure how you would configure that to work here. Are you suggesting an OR'ing circuit fed by the Input and battery pack? I'm not sure how you'd be able to charge the battery in that case. Can you draw something up on www.circuitlab.com?

Thanks,

-NGM

- - - Updated - - -

You may or may not find that a mosfet (probably a P-mos) can turn on and off properly, depending on whether the gate can see a definite reference voltage on the necessary terminal.

A relay may end up being the most convenient option.

A single P-MOS would have all kinds of problem, because as you said a solid reference voltage is going to be a challenge. Relays are out of the question, too big and I'm sticking with solid state. Maybe an optocoupler...

-NGM

 

[snail888]

Hi,you could use a pmos for switch input and battery supply.For pmos typical circuit,you could get it through google site.