How to generate 15V from 5V USB port?

1. How to generate 15V from 5V USB port?

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!!!

2. mc34063 calc

Yes it is posible. and I made it for my pic programmer. Mc34063 used. Here is the calculator:

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3. mc34063a calculator

yes it is possible:
you can use MC34063 switching voltage regulator
http://katalog.elektroda.net/index.php?d_start=0

Regards
Davood

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4. usb 15v

Could you post you programmer schematic?

So I can how to do this boost converter.

Thanks you guys!

Tercio

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5. mc34063 calculation

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

6. 15v from usb

Originally Posted by terciof
Could you post you programmer schematic?

So I can how to do this boost converter.

Thanks you guys!

Tercio
http://www.kitsrus.com/
k149bc

7. mc34063 5v circuit

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

8. usb to 15v

You can use a boost converter, such as the LT1615 from Linear Tech: http://www.linear.com/pc/productDeta...31,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?

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9. calculate mc34063 .xls

You could use a switching regulator -- check out

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