# Step up circuit 5 volt dc to (72 ~90 volt )

#### Subi

Jul 31, 2020
8
1. Hi, can any one help with a compact design of a circuit to step up 5 volt dc to 72 volt minimum (upto maximum 90 volt ).

2. Output voltage can be dc or ac. It's a low current design with a maximum current need for the load is of 50 milli ampere only.

3. Input 5 vdc will be taken from mobile phone backup powerbank. So, even if the powerbank voltage drops below 5 vdc the ckt should work and give a minimum output of atleast 72 volt ( dc or ac)

I need a functional ckt with a small design. Your help is much appreciated.

Thanks

#### ratstar

Aug 20, 2018
485
What troubles are you having in designing it yourself?

You want 20x the voltage.
A circuit would be a voltage doubler.

But u could just use a 20x transformer and not really have a circuit, and it would do the job, but I guess youll need to oscillate the input maybe, to get ac.

I have a circuit for a voltage step up like a voltage doubler that just works with dc, but I cant show it or ppl will get me here.

#### Alec_t

Jul 7, 2015
3,461
The converter will draw nearly 0.75A -1A. How long can your powerbank provide that?
An off-the-shelf DC-DC boost converter would likely be cheaper than trying to build one yourself.

#### Harald Kapp

##### Moderator
Moderator
Nov 17, 2011
13,338
What do you want to do with 72 V ... 90 V ? These are potentially lethal voltages!

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