DC Power Supply Polarity: Can It Work?

[Kurdt]

Is a product that requires a DC power supply but doesn't have any info on the polarity able to work with both polarities?

I'd like to find out before I try it, lest I knacker my device.

Thanks

 

[berkeman]

In general yes, it would have a full wave bridge rectifier at the input, to provide "polarity insensitivity".

What is the device? Can you provide a link to a datasheet or specification?

 

[Kurdt]

Hey berkeman. Thanks for the reply. The best I can come up with is the following but its not exactly the same.

http://catalog.belkin.com/IWCatProductPage.process?Product_Id=252506

Mine has the same basic product code but looks slightly different. I think its an older model.

 

[berkeman]

What does the power input opening look like? Is it a coaxial barrel jack/plug? Those are traditionally positive tip, but not always. There should be some indication of + or - tip, maybe just hard to see if it's molded into the plastic instead of shown on a label. Does the label on the bottom of the product not indicate the polarity of the power input?

 

[Kurdt]

Just a power jack like these:

http://cwe.com.tw/kmportal-deluxe1/img/pictures/r/R0007_DC-POWER.png

No moulding in the plastic nothing around the power jack except "DC 12V/1.25A", and nothing on the sticker on the bottom. Unfortunately I don't have any of the documents that came with it. I normally keep all of them in a box file and I've been right through and of course the only ones I don't have are for this particular product.

 

[berkeman]

Well, there's about a 95% probability that it's positive tip. You could try contacting their customer support folks to double-check. They should have a diode bridge inside (maybe open it up and check?), or at least a blocking diode to prevent knackering.

Is contacting their support or opening it up an option?

 

[Kurdt]

Yes I could contact them. Just thought it would be worth a go asking on here

Thanks berkeman.