I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run it,
but it was expen$ive. The 3.3V regulator I got was a little more than a
buck. Haven't tried it yet.

What say the experts here?

(I also thought about bringing the voltage down to 3 volts with a 0.36
ohm resistor, or maybe a couple diodes in parallel: need to drop 0.3
volts, and the camera draws 2.5 watts [0.86A), so 0.3/0.86 = 0.36 ohms.
Maybe 3 1N4001s in parallel?)


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

On 3/8/2010 3:20 PM David Nebenzahl spake thus:

(I also thought about bringing the voltage down to 3 volts with a 0.36
ohm resistor, or maybe a couple diodes in parallel: need to drop 0.3
volts, and the camera draws 2.5 watts [0.86A), so 0.3/0.86 = 0.36 ohms.
Maybe 3 1N4001s in parallel?)

Scratch that business about using diodes. Dunno what I was thinking
there (or not thinking) ...


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

David Nebenzahl wrote:
On 3/8/2010 3:20 PM David Nebenzahl spake thus:

(I also thought about bringing the voltage down to 3 volts with a 0.36
ohm resistor, or maybe a couple diodes in parallel: need to drop 0.3
volts, and the camera draws 2.5 watts [0.86A), so 0.3/0.86 = 0.36 ohms.
Maybe 3 1N4001s in parallel?)

Scratch that business about using diodes. Dunno what I was thinking
there (or not thinking) ...


carefully check (with noload and full load) the voltage of the
wart.
You might be lucky and use it, as long as it stays between ~2.7 and
~3.4 volts,
but most warts surprise you in a rather unwanted way, and you better
stay away from them....

Sjouke Burry writes:

David Nebenzahl wrote:
On 3/8/2010 3:20 PM David Nebenzahl spake thus:

(I also thought about bringing the voltage down to 3 volts with a
0.36 ohm resistor, or maybe a couple diodes in parallel: need to
drop 0.3 volts, and the camera draws 2.5 watts [0.86A), so 0.3/0.86
= 0.36 ohms. Maybe 3 1N4001s in parallel?)

Parallel diodes don't reduce the voltage drop significantly.

There are diodes that have a much lower voltage drop so one of those might
be acceptable.

Scratch that business about using diodes. Dunno what I was thinking
there (or not thinking) ...

carefully check (with noload and full load) the voltage of the
wart.
You might be lucky and use it, as long as it stays between ~2.7 and
~3.4 volts,
but most warts surprise you in a rather unwanted way, and you better
stay away from them....

If it's a switchmode adapter - light as a feather - then it's probably
regulated at the nameplate voltage which I assume to be 3.3 V from the
subject line. But if you know or can measure the current and its reasonably
constant, the resistor will work.

--
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Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
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Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

If you're using a regulator, there shouldn't be a problem. And you can
always stick a silicon power diode in series with the /regulated/ output to
drop the voltage 0.6V or so.

"David Nebenzahl" wrote in message
.com...
I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run it,
but it was expen$ive. The 3.3V regulator I got was a little more than a
buck. Haven't tried it yet.

What say the experts here?

(I also thought about bringing the voltage down to 3 volts with a 0.36 ohm
resistor, or maybe a couple diodes in parallel: need to drop 0.3 volts,
and the camera draws 2.5 watts [0.86A), so 0.3/0.86 = 0.36 ohms. Maybe 3
1N4001s in parallel?)



Does the 3 volt number come from the fact that the camera runs on two AA
batteries? If it will work with the Li AA 1.7 volt cells, then you should be
ok up to 3.4 volts at least.

Tom

On 3/8/2010 4:51 PM tm spake thus:

"David Nebenzahl" wrote in message
.com...

I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run it,
but it was expen$ive. The 3.3V regulator I got was a little more than a
buck. Haven't tried it yet.

What say the experts here?

(I also thought about bringing the voltage down to 3 volts with a 0.36 ohm
resistor, or maybe a couple diodes in parallel: need to drop 0.3 volts,
and the camera draws 2.5 watts [0.86A), so 0.3/0.86 = 0.36 ohms. Maybe 3
1N4001s in parallel?)

Does the 3 volt number come from the fact that the camera runs on two AA
batteries? If it will work with the Li AA 1.7 volt cells, then you should be
ok up to 3.4 volts at least.

The instructions with camera (a Fuji Finepix A205 that I got for $1)
specify either alkaline (LR6) or rechargable NH-10 AA cells; since this
camera is, what, about 6 years old? I don't think it was made to use LI
cells. So it's probably expecting about exactly 3 volts. (The external
power jack is marked 3V at 2.5W.)

So do you think 3.3 volts is going to bother it?

To the previous confused respondents to this query, I don't have a wall
wart. I was looking at buying a 3-volt one (not 3.3 volts; that's the
voltage regulator I have), but I didn't because, well, I only paid $1
for the camera (it works) and I'm a cheap SOB.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

How many rechargeable cells does it take? Two? Then it should work properly
on two NiMH cells.

Why don't you just use high-capacity rechargeable cells -- which you
doubtless already own -- to power it? Are you going to be trailing a power
cord?

---- The Lady from Philadelphia

"David Nebenzahl" wrote in message
.com...
On 3/8/2010 4:51 PM tm spake thus:

"David Nebenzahl" wrote in message
.com...

I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run it,
but it was expen$ive. The 3.3V regulator I got was a little more than a
buck. Haven't tried it yet.

What say the experts here?

(I also thought about bringing the voltage down to 3 volts with a 0.36
ohm resistor, or maybe a couple diodes in parallel: need to drop 0.3
volts, and the camera draws 2.5 watts [0.86A), so 0.3/0.86 = 0.36 ohms.
Maybe 3 1N4001s in parallel?)

Does the 3 volt number come from the fact that the camera runs on two AA
batteries? If it will work with the Li AA 1.7 volt cells, then you should
be ok up to 3.4 volts at least.

The instructions with camera (a Fuji Finepix A205 that I got for $1)
specify either alkaline (LR6) or rechargable NH-10 AA cells; since this
camera is, what, about 6 years old? I don't think it was made to use LI
cells. So it's probably expecting about exactly 3 volts. (The external
power jack is marked 3V at 2.5W.)

So do you think 3.3 volts is going to bother it?

To the previous confused respondents to this query, I don't have a wall
wart. I was looking at buying a 3-volt one (not 3.3 volts; that's the
voltage regulator I have), but I didn't because, well, I only paid $1 for
the camera (it works) and I'm a cheap SOB.


Well, if it will run off of two nicads, that is only 2.4 volts nominal. So,
it
shouldn't hurt to put one 1N4001 in series with the 3.3 volt supply and
drop it down to about 2.6 volts. That would be the same as two charged
nicads at 1.3 volts each.

Tom

On 9 Mar, 00:20, David Nebenzahl wrote:
I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run it,
but it was expen$ive. The 3.3V regulator I got was a little more than a
buck. Haven't tried it yet.

The fact that the camera uses two cells doesn't mean that it requires
a 3V external supply. My old DC215 which uses 4 cells won't work off a
6V battery plugged into the power socket -- the external PSU is 7.5V.
There is presumably an internal regulator.

Conversely, some cameras do _not_ have any internal regulation and
expect a stabilised supply. But as Sjouke says, cheap wallwarts may
not be stabilised and the voltage can rise alarmingly on low loads.
People trying to avoid buying the manufacturer's expensive PSU have
been known to destroy their cameras.

Is the required voltage (and polarity) given on the camera, probably
near the socket? Or tell us the model and someone may know
(rec.photo.digital may be a better place to ask).

You may be able to get the correct PSU secondhand on eBay from someone
with a dead camera (as long as they didn't kill it as above :-).

Chris

On 3/8/2010 9:21 PM spake thus:

On 9 Mar, 00:20, David Nebenzahl wrote:

I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run it,
but it was expen$ive. The 3.3V regulator I got was a little more than a
buck. Haven't tried it yet.

The fact that the camera uses two cells doesn't mean that it requires
a 3V external supply. My old DC215 which uses 4 cells won't work off a
6V battery plugged into the power socket -- the external PSU is 7.5V.
There is presumably an internal regulator.

Conversely, some cameras do _not_ have any internal regulation and
expect a stabilised supply. But as Sjouke says, cheap wallwarts may
not be stabilised and the voltage can rise alarmingly on low loads.
People trying to avoid buying the manufacturer's expensive PSU have
been known to destroy their cameras.

Is the required voltage (and polarity) given on the camera, probably
near the socket? Or tell us the model and someone may know
(rec.photo.digital may be a better place to ask).

Yes, I thought I'd already written that in this thread, possibly more
than once: it takes 3 volts (and says it uses 2.5 watts), and has the
polarity marked. So I figure a 1 amp power supply would be about right.

I'm tending to believe that 3.3 volts will be just fine, but maybe I'll
wait for more confirmation (or not).

Oh, and I don't intend to use the camera tethered to a power cord: I'd
like to use the external power supply to transfer pictures to my
computer, to save the batteries.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

David Nebenzahl writes:

On 3/8/2010 4:51 PM tm spake thus:

....

The instructions with camera (a Fuji Finepix A205 that I got for $1)
specify either alkaline (LR6) or rechargable NH-10 AA cells; since
this camera is, what, about 6 years old? I don't think it was made to
use LI cells. So it's probably expecting about exactly 3 volts. (The
external power jack is marked 3V at 2.5W.)

Two alkaline AA cells will provide around 3.2V when new. I'm positive
it will work just fine on 3.3V.


So do you think 3.3 volts is going to bother it?

Nope.


To the previous confused respondents to this query, I don't have a
wall wart. I was looking at buying a 3-volt one (not 3.3 volts; that's
the voltage regulator I have), but I didn't because, well, I only paid
$1 for the camera (it works) and I'm a cheap SOB.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"
--
Real life: Thomas Törnblom Email:
Snail mail: Banvallsvägen 14 Phone: +46 18 444 33 21
S - 754 40 Uppsala, Sweden Cellular: +46 70 261 1372

On 3/8/2010 11:17 PM Thomas Tornblom spake thus:

David Nebenzahl writes:

The instructions with camera (a Fuji Finepix A205 that I got for $1)
specify either alkaline (LR6) or rechargable NH-10 AA cells; since
this camera is, what, about 6 years old? I don't think it was made to
use LI cells. So it's probably expecting about exactly 3 volts. (The
external power jack is marked 3V at 2.5W.)

Two alkaline AA cells will provide around 3.2V when new. I'm positive
it will work just fine on 3.3V.

So do you think 3.3 volts is going to bother it?

Nope.

Thank you. I think that increases my confidence level to somewhere
around 97.3%.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

"David Nebenzahl" wrote in message
.com...
On 3/8/2010 9:21 PM spake thus:

On 9 Mar, 00:20, David Nebenzahl wrote:

I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run it,
but it was expen$ive. The 3.3V regulator I got was a little more than a
buck. Haven't tried it yet.

The fact that the camera uses two cells doesn't mean that it requires
a 3V external supply. My old DC215 which uses 4 cells won't work off a
6V battery plugged into the power socket -- the external PSU is 7.5V.
There is presumably an internal regulator.

Conversely, some cameras do _not_ have any internal regulation and
expect a stabilised supply. But as Sjouke says, cheap wallwarts may
not be stabilised and the voltage can rise alarmingly on low loads.
People trying to avoid buying the manufacturer's expensive PSU have
been known to destroy their cameras.

Is the required voltage (and polarity) given on the camera, probably
near the socket? Or tell us the model and someone may know
(rec.photo.digital may be a better place to ask).

Yes, I thought I'd already written that in this thread, possibly more than
once: it takes 3 volts (and says it uses 2.5 watts), and has the polarity
marked. So I figure a 1 amp power supply would be about right.

I'm tending to believe that 3.3 volts will be just fine, but maybe I'll
wait for more confirmation (or not).

Oh, and I don't intend to use the camera tethered to a power cord: I'd
like to use the external power supply to transfer pictures to my computer,
to save the batteries.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

There's nothing wrong with the diode route to drop the voltage by a
(reasonably) constant amount, but just use a Schottky type, which will have
a forward voltage drop of around 0.3 to 0.4v - or just about what you're
looking for ...

Arfa

On 3/10/2010 9:48 AM Arfa Daily spake thus:

On 9 Mar, 00:20, David Nebenzahl wrote:

I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run it,
but it was expen$ive. The 3.3V regulator I got was a little more than a
buck. Haven't tried it yet.

There's nothing wrong with the diode route to drop the voltage by a
(reasonably) constant amount, but just use a Schottky type, which will have
a forward voltage drop of around 0.3 to 0.4v - or just about what you're
looking for ...

Can they handle the current (~ 1A)?

In any case, I'm reasonably sure that I can run the camera on the 3.3
volts without fear of damage.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

"David Nebenzahl" wrote in message
.com...
On 3/10/2010 9:48 AM Arfa Daily spake thus:

On 9 Mar, 00:20, David Nebenzahl wrote:

I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run
it,
but it was expen$ive. The 3.3V regulator I got was a little more than
a
buck. Haven't tried it yet.

There's nothing wrong with the diode route to drop the voltage by a
(reasonably) constant amount, but just use a Schottky type, which will
have a forward voltage drop of around 0.3 to 0.4v - or just about what
you're looking for ...

Can they handle the current (~ 1A)?

Of course they can. All switchmode power supplies, including those that
provide many amps of output, use such diodes as their secondary-side
rectifiers ...

Arfa

On Mon, 08 Mar 2010 15:20:07 -0800, David Nebenzahl
put finger to keyboard and composed:

I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run it,
but it was expen$ive. The 3.3V regulator I got was a little more than a
buck. Haven't tried it yet.

Unless the 3.3V regulator is a fixed type, it may be possible to bring
it down to 3.0V by changing a feedback resistor. Can we see a photo of
the PCB?

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

On 3/10/2010 7:45 PM Franc Zabkar spake thus:

On Mon, 08 Mar 2010 15:20:07 -0800, David Nebenzahl
put finger to keyboard and composed:

I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run it,
but it was expen$ive. The 3.3V regulator I got was a little more than a
buck. Haven't tried it yet.

Unless the 3.3V regulator is a fixed type, it may be possible to bring
it down to 3.0V by changing a feedback resistor. Can we see a photo of
the PCB?

It's just a TO-220 regulator, for chrissakes. An NTE something something
.... don't have it here at the moment, but it's just a fixed 3.3V
regulator. So no, not possible to rejigger it w/a resistor.

I'm just going to use it as-is. I don't think 10% overvoltage will hurt
the cam.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

Unless the 3.3V regulator is a fixed type, it may be possible
to bring it down to 3.0V by changing a feedback resistor.

One assumes that a 3.3V regulator is a fixed regulator (or otherwise the OP
would not be having a problem).

Fixed regulators' outputs can be changed, too, but only raised. This is
usually done by inserting a Zener diode in the ground-reference line.
(CMIIW.)

On Wed, 10 Mar 2010 21:38:23 -0800, David Nebenzahl
put finger to keyboard and composed:

On 3/10/2010 7:45 PM Franc Zabkar spake thus:

On Mon, 08 Mar 2010 15:20:07 -0800, David Nebenzahl
put finger to keyboard and composed:

I'm wondering if running a 3-volt device (cheap digital camera) on 3.3
volts will hurt it. Yeah, I coulda gotten a 3-volt wall wart to run it,
but it was expen$ive. The 3.3V regulator I got was a little more than a
buck. Haven't tried it yet.

Unless the 3.3V regulator is a fixed type, it may be possible to bring
it down to 3.0V by changing a feedback resistor. Can we see a photo of
the PCB?

It's just a TO-220 regulator, for chrissakes. An NTE something something
... don't have it here at the moment, but it's just a fixed 3.3V
regulator. So no, not possible to rejigger it w/a resistor.

I'm just going to use it as-is. I don't think 10% overvoltage will hurt
the cam.

I thought that a standard 3-terminal regulator with a 1A current limit
may not be appropriate for the task. That's why I assumed you had
something more sophisticated. After all, you did get the camera for
$1. :-)

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.