Power supply explanation, no, its not about PSA or ACA

[airhole]

A friend of mine got a Tonebone, and somehow its not working. He did not use the adaptor given to him, because our ratings are different in Asia.

So I am wondering what does it mean? Anyone can help explain? Excerpt from an email from Radial:

"Q: Can I run the Tonebone pedals on any other power supply or multi-pedal power device?
A: Unfortunately, unless the device you have has a floating 15V unregulated output: i,e: neither positive or  negative rail referenced to ground, you cannot use  any other supply than the one we send along with your Tonebone."

"Q: What kind of power does the Tonebone require?
A: Tonebone requires 15V (400mA minimum) unregulated power supply to work properly."

"Q: What happens if I run an 18V or high voltage to the Tonebone?
A: You will overheat the internal power supply circuitry and unfortunately damage your Tonebone."

Thanks in advance!

cheers,
George

[airhole]

I mean, what is meant by floating 15V unregulated output?

cheers,
George

[jplaudio]

I mean, what is meant by floating 15V unregulated output?

cheers,
George

Floating is ungrounded. Most wallwarts are floating as there is no ground connection on the AC to reference ground.
Use a 15v supply capable of 400ma and proper polarity with no connection to ground on the AC side and it should work. The primary of the PS should match your local standard.

[Boofhead]

To add to jplaudio's comments.

The problem with unregulated supplies is that an output voltage of 15VDC doesn't tell you much.  It could be 15VDC under full load, in which case the open circuit voltage will be around say 20VDC.   Alternatively it could be 15VDC with no load and the voltage will drop under load.   It's likely the actual voltage will be somewhere in between.

I suggest you contact the manufacturer and find out exactly what the open circuit voltage is for the supplied wall-wart, and if possible the loaded voltage.  If a schematic was available you can often make a judgement from that.

The second problem is when you buy an off the shelf wall-wart you have the same problem in that you don't know what conditions the rated voltage is specified at.

It's a very simple question but the precise answer require knowing details which just aren't available - it's actually best to measure the voltage an off the shelf unit.

In many cases you can just buy any old wall wart with the specified voltage and it will work,  despite all the unknowns , that's because  the device can cope with wide voltage variations.

[niftydog]

floating 15V unregulated output: i,e: neither positive or negative rail referenced to ground

This is a very strange thing to say.

Ground is an abitrary point in a circuit. So, saying "not referenced to ground" is essentially meaningless. You could, if you wanted to, decide to call one pin of the output of the supply "ground" and it would make zero difference to the operation of the circuit.

The tonebone itself must have a ground point in the circuit, and as soon as you connect any power supply to it... guess what? It's "referenced to ground"!!!

Still, most wall warts would be "floating" in the sence that there is no reference to "earth". Perhaps this is what they mean?!

As for what to replace it with; look at the adapter you received with the tonebone. Take note of the voltage and current ratings and try to replace it as closely as possible with one that is designed for your part of the world. If you get one with to high a current rating, then the unregulated voltage may be too high for the circuit.

It could be 15VDC under full load, in which case the open circuit voltage will be around say 20VDC. Alternatively it could be 15VDC with no load and the voltage will drop under load.

I think you'll find that it's 15VDC at the rated current (ie; full load).

[airhole]

Firstly, I would like to thank you guys for the information. It is really really helpful.

secondly, yeah i get the point. Think I know what i need to do now.

Cheers,
George