Proper AC Adapter?

[Gathomblipoob]

I just ordered a Novag Aquamarine RISC II and am trying to make sure I buy the correct AC adapter for it. I' know the voltage and amperage, but I'm unsure of the polarity. The German site I'm using just says "plus outside," but I'm uncertain of what that means.

[Kasparov111]

I just checked my Novag adapter that I purchased from that Nigglesmann site and it shows a positive polarity for the tip that plugs into the board. They are out of stock at the moment though.

[Tibono2]

There is no trap here; plus outside is just plus outside. It is the external cylindrical metal surface of the adapter plug, most easy to make contact with.
On top of the plug, you should see a plastic insulating material (most usually black). Less accessible metal cylinder inside is expected by your Novag computer to be the negative pole; connection with it will be established from a pin which is centered, computer side.
From the picture you provided, it is of course the bottom configuration.

[Gathomblipoob]

There is no trap here; plus outside is just plus outside. It is the external cylindrical metal surface of the adapter plug, most easy to make contact with.
On top of the plug, you should see a plastic insulating material (most usually black). Less accessible metal cylinder inside is expected by your Novag computer to be the negative pole; connection with it will be established from a pin which is centered, computer side.
From the picture you provided, it is of course the bottom configuration.

Ah. Thank you for the explanation. I haven't had to purchase an AC adapter in quite a few years. If I get your meaning, the diagrams I posted are cross-sections of the plug, which would make what you said make more sense to me. I'm slapping my forehead right now.Thanks again!

[Berger]

Hi,

This family of Novag chess computers runs on DC 9V and consumes very little current (Less than 0.3A, i.e. 300mA). You have several options: buy an original Novag power adapter; buy an adapter with a central positive, cut the cable and reattach by reversing the wires to reverse polarity; buy a universal multi-voltage AC/DC adapter where an interchangeable connector is usually supplied which can be connected with both polarities; etc.

My recommendation however is to buy one of those power adapters sold for guitar effects pedals, as it is common for them to use this polarity and 9V DC output.

By the way, the connector dimensions are also usually the same, but just in case:
outside diameter x inside diameter = 5.5 mm x 2.1 mm.

Best,
Gerardo

[Gathomblipoob]

My recommendation however is to buy one of those power adapters sold for guitar effects pedals, as it is common for them to use this polarity and 9V DC output.

By the way, the connector dimensions are also usually the same, but just in case:
outside diameter x inside diameter = 5.5 mm x 2.1 mm.

Best,
Gerardo

You're right about the guitar effect pedal adapters. I had read about them a couple of nights ago. Thank you for the info about the plug dimensions. I found at least one on Amazon that would fit the bill. Thank you!