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How to generate 15V from 5V USB port?

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terciof

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Hi All!

I have a +5V and I need a +15V generated from that +5V. This power supply is the USB port.

The currency is very low(Maximun 50mA).

It will be in 15V for 3 or 4 sec.

So, I need to generate 15V from 5V USB port.

Is that possible?

Thanks all!!!
 

terciof

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usb 15v

Could you post you programmer schematic?

So I can how to do this boost converter.

Thanks you guys!

Tercio
 

phoenixdk

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mc34063 calculation

what about clamping the 5v.. not sure if its possible to draw 50 mA from the circuit, what do people think ?
 

ramy gad

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mc34063 5v circuit

there is a chip and easy 555 timer circuit can do this job search google for it
 

VVV

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usb to 15v

You can use a boost converter, such as the LT1615 from Linear Tech: www.linear.com/pc/productDetail.do?navId=H0,C1,C1003,C1042,C1031,C1061,P1775

or MAX8575 from Maxim www.maxim-ic.com/quick_view2.cfm/qv_pk/4369/ln/

The USB port can source up to 100mA, as per the USB specification.
Since the available input power is Pin=5V*100mA=500mW, your output current can only be Iout=Pout/Vout=Pin*η/Vout. Typically, η=0.9 for a boost (though it can be lower), so your maximum output current can only be Iout=500mW*0.9/15V=30mA. This is a best-case scenario. In reality, the input voltage will be lower than 5V, due to voltage drops in the USB cable and connectors. Therefore, an output current of about 25mA is a more realistic expectation.

Does that work for you?
 

v_c

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calculate mc34063 .xls

You could use a switching regulator -- check out

http://www.national.com/appinfo/power/

for more information. You can enter in the details of your specifications and
it will suggest a part for you. You can use this as your starting point.

Best of luck,
v_c
 

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