I'm thinking about making a little dock or cradle to protect/augment my PS-02.
Since the battery life is a little weak, one of the desired features was to build up the 9vdc required by the power jack with larger batteries such as AA, C or even D. I'll have to look at the numbers between six of those batteries or a few 9 volt batteries in parallel to see which is more economical.
Another thing that concerns me is the constant plugging and unplugging of the headphones and guitar input, so the cradle would have extensions of these jacks that would remain plugged in to the PS-02. It will be easier to replace the extensions than whatever is inside the PS-02. I may also look at doing a stereo breakout with RCA jacks or some such on the output as well, but it depends on the size of the apparatus.
The size will likely be dictated by the batteries, but obviously I'd like to keep the unit small. Has anyone done something like this or given any thought to it?
The batteries will take away the portability factor and at home you can just use the adaptor. The whole exercise just seems like a good way of destroying a good system.
Root5
Out N D Woods
November 20 2001, 8:35 AM
The point is that the PS-02 can't run long enough on batteries to really reasonably use it remotely. If you're planning on going outside for inspiration, you'd BETTER take lots of spare batteries! The battery life is further shortened by the fact that you'd also better turn the unit off as soon as you see the lo-batt indication or you may blow the format on the card and loose your goodies. The idea of a dock is to find a middle ground between form and function... especially since you have to carry the batteries anyway. The unit is cool, but you really can't use it on your belt, except for listening... and it ain't no mp3 player! So, until we get better batteries, somthing that could at least double the battery life would be worth a little more baggage. Even the cute little PS-02 is too much to carry after the batteries are dead!
So, it's all relative.
I think it would be an nice option/accessory to have. I'd use a dock when I want to work out an idea in the park, but still use it 'as is' when I need to go to the bathroom.
PS. I've had no problems plugging in and out the adaptor without turning the unit off. I believe the unit employs a DC-DC converter for it's power conditioning.
batteries
November 20 2001, 1:51 PM
I'd expect even going to AA batteries might be an improvement over AAA, however the unit seems to leave the LCD light on when it thinks its connected to AC which would be the case for this idea. I'll bent the overhead from having the lamp on all the time would mean you'd have to go up to 'C' size batteries to get a real time boost.
I'm sure a single 9V would not offer the runtime of the 4 AAA batteries, but 2 or 4 9V might offer good runtime and the flat surface they present may be desirable. What does 4-5 9V cost compared to 6 'C' batteries?
I'd assume that you are correct about some additional power regulation when running from AC since it only has 6v of batteries, but uses 9V DC in. This is probably so that it has enough headroom to make a stable 6v from the external adapter (which is probably quite noisy and unstable)
Mike
Portable Power
November 21 2001, 1:58 PM
My solution for battery power in the field was to tap my 4"D" cell flashlight with a power out jack on the butt end and run a patch cord to the external power input of the PS-02. This gives me almost limitless power and I still got a working flashlight beside me. As long as the volts are good and you get the polarity correct, power is power.
Chris Hurley
Re: PS-02 Dock
November 21 2001, 2:23 PM
That's cool! Did it mind that you had only 6v on the input instead of 9?
Root5
Battery Power Densities
November 21 2001, 2:30 PM
Hi Chris!
I don't know if 9Vs will be viable because of their relatively low power density. But, we'll never really know unless it's tried. Partly because I don't know what the actual average current draw (w/light on & w/light off) of the PS-02 actually is, just that it's <=300mAH. That's cutting it close for 9Vs, but if you try it, you might consider 2 or 4 NiMH 9V@170mAH cells. In any case, this info might be handy:
--------------------------------
Nickel Cadmium (NiCad) batteies:
--------------------------------
Pros:
rechargeable
high power density (better than Alkaline)
cheap
moderate life
Cons:
1.2V cell voltage
they like to leak
recharge 'memory' problem
fast (knee like) discharge curve
Approximate cell 'strength':
AAA ~ 250mAH
AA ~ 1000mAH
C ~>10000mAH
9V ~ 300mAH
--------------------------------
Alkaline batteries:
-------------------
Pros:
1.5V cell voltage
high power density
cheap
good (ramp like) discharge curve
cons:
not rechargable (my verdict is not in yet for the rechargeable ones)
short life
Approximate cell 'strength':
AAA ~ 250mAH (initially, but falls off quickly)
AA ~ 1000mAH (initially, but falls off quickly)
C ~ 2500mAH (initially, but falls off quickly)
9V ~ 150mAH (I don't Know the curve)
----------------------------
Nickel Metal Hydride (NiMH):
----------------------------
Pros:
almost perpetually rechargable
no 'NiCad - like' memory problem
1.5 cell voltage
great power density (about 2X alkaline... except for the 9V)
relatively cheap
Cons:
real BAD discharge curve. (ramp then CLIFF!)
Approximate cell 'strength':
AAA ~ 700-800mAH
AA ~ 1700-1800mAH
C ~>22000mAH (I think... I'll have to double check!)
9V ~ 170mAH (I know of one like this, most others are much worse, and not really 9V!)
------------------------------------------------------
All that said... Alkalines are the best for the PS-02 because of the P.D. vs cost, but most of all... it's discharge 'ramp' allows time for low batt detection controlled shutdown.
Also...
The PS-02 safely allows seamless, on-the-fly transition to adapter power. Therefore, you can safely plug in adapter without turning the unit off.
The power stage is well designed and filtered, and uses separate regulators for the battery and adapter inputs. The backlight mode is smart and pretty cool. As you probably already know, the battery mode is programmable, and the adapter mode is always on....
but what you may not know is that the backlight mode seems to be based on the input voltage threshold (instead of a mech. switch). So there should be a way to keep the light off by regulating the adapter power voltage. I haven't verified it, but my guess is that it's around 7V. I know it's above 6V.
Cheers!
Mike
Re: Chris Hurley
November 21 2001, 3:32 PM
Correction, its been so long since I unloaded the batteries in the flashlight I lost count. Its a 6 cell flashlight. I was thinking about the 4 in the PS-02.
