Power Supply

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steev
 
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Joined: Thu Oct 20, 2005 7:35 pm

Power Supply

Post by steev »

Ok,

Out of Limors suggested kitlist this is the last thing which I'm really not sure about:

Power Supply
It can be a thousand dollar arbitrary waveform generator, or a 9V hooked up to an LM317 & potentiometer.

I've only ever used typical bench power supplies that are used in schools/colleges... I needa a cheap solution basically (less than 30 UKP).

thanks

Steev

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etaoin
 
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Post by etaoin »

You need an adjustable power supply to generate the tuning voltages.
You'll need them here: http://www.ladyada.net/make/x0xb0x/fab/vco/index.html

I just used a CV/Gate keyboard by the way. That's not on the list, but it does provide pretty exact voltages.

evilxsystems
 
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Post by evilxsystems »

holy BANNED that's a good idea! why didn't I think of that :roll:

Guest
 

Re: Power Supply

Post by Guest »

steev wrote:
Power Supply
It can be a thousand dollar arbitrary waveform generator, or a 9V hooked up to an LM317 & potentiometer.

I've only ever used typical bench power supplies that are used in schools/colleges... I needa a cheap solution basically (less than 30 UKP).
Steev
Hi Steev,

To power the X0xb0x you can get a suitable mains adapter for under £10 from Maplin.

You don't NEED a variable voltage source for setting the tuning. You can do this after the kit is fully built using the built-in keyboard.

Guest
 

Post by Guest »

Etaoin wrote:You need an adjustable power supply to generate the tuning voltages.
Not true - you don't have to set the tuning at this stage, its much simpler to wait until the kit is fully built, then you can use the x0xb0x keyboard mode and a guitar tuner.

ianfuture
 
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Joined: Thu Oct 13, 2005 5:29 am

Re: Power Supply

Post by ianfuture »

Anonymous wrote:
steev wrote:
Power Supply
It can be a thousand dollar arbitrary waveform generator, or a 9V hooked up to an LM317 & potentiometer.

I've only ever used typical bench power supplies that are used in schools/colleges... I needa a cheap solution basically (less than 30 UKP).
Steev
Hi Steev,

To power the X0xb0x you can get a suitable mains adapter for under £10 from Maplin.

You don't NEED a variable voltage source for setting the tuning. You can do this after the kit is fully built using the built-in keyboard.
I was in Maplin yesterday all ready to buy a power supply, only to be confused by the variety on offer.
They nearly all had selectable voltages. So that was ok
But they had different current settings. some 300mA , some 900mA, some 1200mA. Which is best? Or does it not matter?

Also could someone clear up the issue of whether these power supplies convert the UK mains AC to a DC output? If so is this what I want? Or do I need one that keeps the power at an AC output because the x0x will change it to a DC ? I'm confused about this. As I understand it I need to feed an AC into the x0x so any power supply that converts to DC is not much usefull. Or am I totally wrong?

Thanks..
Ian

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etaoin
 
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Post by etaoin »

Not true - you don't have to set the tuning at this stage,
That doesn't make my point "not true". If you need tuning voltages to tune the VCO right after building it, you'll need an adjustable supply.
I didn't say anything about needing to tune it at that stage. I only did rough tuning myself at that point.

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Post by Guest »

Etaoin wrote:You need an adjustable power supply to generate the tuning voltages.
This is not true.
There is a big difference between a voltage source, eg a cv keyboard / x0x keyboard mode and an adjustable power supply.
To clarify - you DO NOT NEED an adjustable power supply to build this kit or tune it. The only power supply you need is the one to power the x0xb0x itself (9V AC).

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etaoin
 
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Post by etaoin »

There is a big difference between a voltage source, eg a cv keyboard / x0x keyboard mode and an adjustable power supply.
Ok, I agree I should probably more correctly have called it an adjustable voltage supply instead of an adjustable power supply. For the purpose of supplying tuning voltages however, there is little difference between a cv keyboard and a bench power supply. Both provide fixed voltages.
And indeed, you don't need it to build the b0x. You only need one if you want to tune the VCO right after building it (which isn't necessary, but happens to be in the manual so many people will probably do it...)

Guest
 

Re: Power Supply

Post by Guest »

To answer your question directly. You need a power supply who's input is whatever you have in your part of the world and whose output is 9VAC 500mA or greater. The voltage needs to be 9VAC, but the mA will work as long as it is 500mA or greater (at least that is what is supplied with the kit so I wouldn't go with lower than 500).

So... 9VAC 500mA, 9VAC 600mA, 9VAC 1000mA all of these will work...

cheesy
 
Posts: 94
Joined: Tue Oct 11, 2005 2:06 am

Re: Power Supply

Post by cheesy »

Anonymous wrote:To answer your question directly. You need a power supply who's input is whatever you have in your part of the world and whose output is 9VAC 500mA or greater. The voltage needs to be 9VAC, but the mA will work as long as it is 500mA or greater (at least that is what is supplied with the kit so I wouldn't go with lower than 500).

So... 9VAC 500mA, 9VAC 600mA, 9VAC 1000mA all of these will work...
The posts above are talking about something completely different, they're talking about the power supply used to supply the voltage needed to tune the x0x, not the power supply used to power the x0x.

Anyway, I've just completed the x0x power supply and VCO, but I don't have a variable power supply as mentioned above. At this point I don't care about tuning it, I just want to make sure it's working, so can I just use a pair of AA batteries (about 2.6VDC) and tune it later?

cheesy
 
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Joined: Tue Oct 11, 2005 2:06 am

Post by cheesy »

oh and where do we take the ground of our power supply to? just any ground on the board?

leonard
 
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Re: Power Supply

Post by leonard »

Anonymous wrote: So... 9VAC 500mA, 9VAC 600mA, 9VAC 1000mA all of these will work...
Is this only for regulated power supplies? what if I have unregulated supply which outpus 1A, will this fry the x0x?

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