LM2577 stepping up question

[Jay112]

I need 2 voltages for my project: 5v for an Arduino Nano, and 34v to power a MingHe B3603 that will be used as a current limiter, feeding 30v 20mA (to an ionic silver generator).

I've never stepped up voltage before, so forgive my ignorance.

The Arduino needs 5v at the Vin pin, and will be using less than 100mA. I'm not exactly sure how much current the B3603 draws when outputting 30v limited at 20mA, but I'm guessing it's not a large load.

Could I use a 5v wall wart, use that for the Arduino's Vin pin, and also use that for stepping up to 34v to feed the B3603? I've made a project like this before by combining 2 wall warts and then stepping them down for the Arduino, but I'm trying to avoid the mess of having 2 wall warts.

Thanks!

[michaeliv]

If I'm understanding you correctly you want to put 2 boost converters in series ? Why is that ?
Why not use the 5v from adapter + a single converter from 5v directly to 30v ?
However MingHe B3603 will theoretically not work since it has minimum 5v input.
Why do you need 34v input for the  MingHe B3603?

[Jay112]

If I'm understanding you correctly you want to put 2 boost converters in series ? Why is that ?
Why not use the 5v from adapter + a single converter from 5v directly to 30v ?
However MingHe B3603 will theoretically not work since it has minimum 5v input.
Why do you need 34v input for the  MingHe B3603?

Thanks for replying.

Not really 2 boost converters in series. I need the B3603 to give me 30 volts, limiting it to only 20mA. For the B3603 to be able to output 30 volts, it needs 34v as the input.

The reason why I need the B3603 there is because the user might need to be able to modify the voltage/current settings. So if the user decides that they prefer 28v and 80mA, then they can easily do the change on their own without affecting the rest of the circuit.

Would there be anything wrong with using a 5v wall wart to feed the Arduino and the LM2577, with the LM2577 stepping the 5v up to 34v for the B3603? Since I've never done any stepping-up before, I just want to make sure I'm not overlooking anything.

Also, as a sidenote for anyone who's reading: I recently read that the XL6009 is an upgrade to the LM2577. Do you generally agree that it's a better component?

[michaeliv]

Oulps I thought that the B3603 is a boost converter. It's actually a buck converter.
What you're trying to do would work. There is nothing wrong using 1 5v adapter to power both. If the LM2577 fails you might get 30V on the Arduino and fry it.
The obvious solution would be to get a step-up converter that also has constant current feature but I can't find any easily on eBay.
The ones that I see have a minimum input voltage of 7v to use the CC feature.
The XL6009 is probably better due to the 400khz frequency vs 52khz for the LM2577 .

[Jay112]

Oulps I thought that the B3603 is a boost converter. It's actually a buck converter.
What you're trying to do would work. There is nothing wrong using 1 5v adapter to power both. If the LM2577 fails you might get 30V on the Arduino and fry it.
The obvious solution would be to get a step-up converter that also has constant current feature but I can't find any easily on eBay.
The ones that I see have a minimum input voltage of 7v to use the CC feature.
The XL6009 is probably better due to the 400khz frequency vs 52khz for the LM2577 .

Awesome! Thanks for the help!