Question about switching regulator circuit for charging phone's battery

[zenniz]

I'm building a switching regulator to convert from 12V to adjustable 5-6V to charge phone's battery.

Should i put a IN4001 diode right before the load to prevent phone from discharging and change to output voltage?

 

[betwixt]

I assume you are worried about it discharging back into the regulator when still plugged into the phone but the supply is turned off. It probably isn't necessary but if you do add one, it has to be wired after C2 and before R1 on your schematic so the voltage drop in the 1N4001 can be compensated in the feedback loop. In other words, the regulator produces 0.6V extra to compensate for it being dropped in the diode. You will still lose a small current into the resistors but it will be very small.

Brian.

 

[Sunny55]

I see you have voltage dividers near the data + and - of the usb connector. It is designed for Apple products only? I found an IC that can support both Apple n Android system. Check this out TPS2511.

 

[zenniz]

I see you have voltage dividers near the data + and - of the usb connector. It is designed for Apple products only? I found an IC that can support both Apple n Android system. Check this out TPS2511.

I'm building a universal 3rd party charger. Will i damage other phone that don't use the same charging mechanism as apple products?

 

[Sunny55]

If you use the mentioned IC, your problem is solved as it uses auto detect that checks the data - and + when phone is connected. I have tried it n can charge most Androids. Read the datasheet for more info.

 

[zenniz]

If you use the mentioned IC, your problem is solved as it uses auto detect that checks the data - and + when phone is connected. I have tried it n can charge most Androids. Read the datasheet for more info.

I mean for my circuit diagram shown above, will it damage the phone (Apple, android, etc) base on your experience?