Power adapter advice

[Uncle Leon]

Hi all,

So I noticed that connecting the PreenFM2 via USB causes some kind of interference with my USB ports on my PC. Might have to do with the USB ports and not necessarily the PreenFM2. So now I'm looking for a power adapter to power it up. I'm not very knowledgeable on this topic, but as it says on the machine I will need a power adapter that uses 7.5 or 9 volt? What else should I be paying attention to? Don't want to mess up the PreenFM2 with an adapter with different specs or anything. Thanks.

[Xavier]

Hi,

With 7.5V the 7805 5V regulator will be cooler.

Plug size is 2.1mm.

You need 300mA or more, so it should be 99.9% of the available power supply.
The only thing is the polarity, must be ground outside which are the most common ones.

Any power supply that works with the Shruthi will work with the preenfm.
So you can google "shruthi power supply."

Xavier

[Uncle Leon]

Hi,

With 7.5V the 7805 5V regulator will be cooler.

Plug size is 2.1mm.

You need 300mA or more, so it should be 99.9% of the available power supply.
The only thing is the polarity, must be ground outside which are the most common ones.

Any power supply that works with the Shruthi will work with the preenfm.
So you can google "shruthi power supply."

Xavier

Thanks Xavier. I'm looking at an adapter that has the specification 'center negative'. Does that mean the tip is positive, and thus it should work? Or is center negative not the right one?

[Xavier]

I'm not a power supply splecialist 
But 'center negative' sounds wrong.
Luckily most of the power supply are 'center positive'.

[don_sook]

I bought my power supply from Van Daal Electronics.

You can also find power supplies from eBay if you search '2.1mm 9v adapter'. I think this would work as well.

Just make sure that it's centre positive, plug size is 2.1mm, volts is between 7.5 or 9, minimum 300mA current.