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From: isw on 15 Mar 2010 01:01 In article <4b99d1e2$0$2377$822641b3(a)news.adtechcomputers.com>, David Nebenzahl <nobody(a)but.us.chickens> wrote: > To bring this little saga to a close, I built a little AC adapter for my > Fuji Finepix digicam: brought in 5 volts from a little Samsung wall > wart, put the regulator and an electrolytic cap in a film can on a > little piece of perfboard, and brought the power out to a 2.5mm power > mini jack. > > The long and short of it is, the camera doesn't work on this supply. It > puts out 3.25 volts alright, even when plugged into the camera, but the > camera just sits there and does nothing. My suspicion is that the power > jack is just not quite the right size to make contact (or else there's > something screwed up inside the camera that makes it not accept external > power, which seems unlikely). What kind of regulator are you using? A lot of regulators will not function properly with only 1.75 volts across them. It might be failing only when the camera wants more then average current -- like when it's trying to focus. Isaac
From: David Nebenzahl on 16 Mar 2010 01:29 On 3/14/2010 9:01 PM isw spake thus: > In article <4b99d1e2$0$2377$822641b3(a)news.adtechcomputers.com>, > David Nebenzahl <nobody(a)but.us.chickens> wrote: > >> To bring this little saga to a close, I built a little AC adapter for my >> Fuji Finepix digicam: brought in 5 volts from a little Samsung wall >> wart, put the regulator and an electrolytic cap in a film can on a >> little piece of perfboard, and brought the power out to a 2.5mm power >> mini jack. >> >> The long and short of it is, the camera doesn't work on this supply. It >> puts out 3.25 volts alright, even when plugged into the camera, but the >> camera just sits there and does nothing. My suspicion is that the power >> jack is just not quite the right size to make contact (or else there's >> something screwed up inside the camera that makes it not accept external >> power, which seems unlikely). > > What kind of regulator are you using? A lot of regulators will not > function properly with only 1.75 volts across them. It might be failing > only when the camera wants more then average current -- like when it's > trying to focus. It's an NTE 1904 (replacement for ECG1904). Similar to the LM78xx series, I guess; just your standard 3-terminal positive regulator. Not sure what you mean by only 1.75 volts across; do you mean the difference between input and output? In any case, I assume it's working correctly, since I can see 3.xx volts at the output. I tried it using a variable DC power supply; no better result. I'm thinking there's something wrong with the camera. (And by not working I mean the camera doesn't respond to the power switch *at all*. No little beeps, no display, nothing.) -- You were wrong, and I'm man enough to admit it. - a Usenet "apology"
From: isw on 16 Mar 2010 00:56 In article <4b9f0855$0$2381$822641b3(a)news.adtechcomputers.com>, David Nebenzahl <nobody(a)but.us.chickens> wrote: > On 3/14/2010 9:01 PM isw spake thus: > > > In article <4b99d1e2$0$2377$822641b3(a)news.adtechcomputers.com>, > > David Nebenzahl <nobody(a)but.us.chickens> wrote: > > > >> To bring this little saga to a close, I built a little AC adapter for my > >> Fuji Finepix digicam: brought in 5 volts from a little Samsung wall > >> wart, put the regulator and an electrolytic cap in a film can on a > >> little piece of perfboard, and brought the power out to a 2.5mm power > >> mini jack. > >> > >> The long and short of it is, the camera doesn't work on this supply. It > >> puts out 3.25 volts alright, even when plugged into the camera, but the > >> camera just sits there and does nothing. My suspicion is that the power > >> jack is just not quite the right size to make contact (or else there's > >> something screwed up inside the camera that makes it not accept external > >> power, which seems unlikely). > > > > What kind of regulator are you using? A lot of regulators will not > > function properly with only 1.75 volts across them. It might be failing > > only when the camera wants more then average current -- like when it's > > trying to focus. > > It's an NTE 1904 (replacement for ECG1904). Similar to the LM78xx > series, I guess; just your standard 3-terminal positive regulator. According to the data sheet, it's *not* similar to a LM78xx because it does have a low differential requirement -- 0.45V. > Not sure what you mean by only 1.75 volts across; do you mean the > difference between input and output? Yes. Some regulators (LM78xx for example), need more like 2.5V to work properly. > In any case, I assume it's working > correctly, since I can see 3.xx volts at the output. You do happen to be using a low-dropout device, but still, you have to measure the voltage under maximum expected load, not open circuit, to really see whether it'll work. > I tried it using a variable DC power supply; no better result. I'm > thinking there's something wrong with the camera. > > (And by not working I mean the camera doesn't respond to the power > switch *at all*. No little beeps, no display, nothing.) Does it work if you stick the proper batteries in it? Isaac
From: Warren Block on 16 Mar 2010 01:12 David Nebenzahl <nobody(a)but.us.chickens> wrote: > > It's an NTE 1904 (replacement for ECG1904). Similar to the LM78xx > series, I guess; just your standard 3-terminal positive regulator. > > Not sure what you mean by only 1.75 volts across; do you mean the > difference between input and output? In any case, I assume it's working > correctly, since I can see 3.xx volts at the output. > > I tried it using a variable DC power supply; no better result. I'm > thinking there's something wrong with the camera. > > (And by not working I mean the camera doesn't respond to the power > switch *at all*. No little beeps, no display, nothing.) Polarity on the jack, or maybe a blown picofuse? -- Warren Block * Rapid City, South Dakota * USA
From: David Nebenzahl on 16 Mar 2010 02:16
On 3/15/2010 8:56 PM isw spake thus: > In article <4b9f0855$0$2381$822641b3(a)news.adtechcomputers.com>, > David Nebenzahl <nobody(a)but.us.chickens> wrote: > >> On 3/14/2010 9:01 PM isw spake thus: >> >> > In article <4b99d1e2$0$2377$822641b3(a)news.adtechcomputers.com>, >> > David Nebenzahl <nobody(a)but.us.chickens> wrote: >> > >> >> To bring this little saga to a close, I built a little AC adapter for my >> >> Fuji Finepix digicam: brought in 5 volts from a little Samsung wall >> >> wart, put the regulator and an electrolytic cap in a film can on a >> >> little piece of perfboard, and brought the power out to a 2.5mm power >> >> mini jack. >> >> >> >> The long and short of it is, the camera doesn't work on this supply. It >> >> puts out 3.25 volts alright, even when plugged into the camera, but the >> >> camera just sits there and does nothing. My suspicion is that the power >> >> jack is just not quite the right size to make contact (or else there's >> >> something screwed up inside the camera that makes it not accept external >> >> power, which seems unlikely). >> > >> > What kind of regulator are you using? A lot of regulators will not >> > function properly with only 1.75 volts across them. It might be failing >> > only when the camera wants more then average current -- like when it's >> > trying to focus. >> >> It's an NTE 1904 (replacement for ECG1904). Similar to the LM78xx >> series, I guess; just your standard 3-terminal positive regulator. > > According to the data sheet, it's *not* similar to a LM78xx because it > does have a low differential requirement -- 0.45V. > > >> Not sure what you mean by only 1.75 volts across; do you mean the >> difference between input and output? > > Yes. Some regulators (LM78xx for example), need more like 2.5V to work > properly. > >> In any case, I assume it's working >> correctly, since I can see 3.xx volts at the output. > > You do happen to be using a low-dropout device, but still, you have to > measure the voltage under maximum expected load, not open circuit, to > really see whether it'll work. > >> I tried it using a variable DC power supply; no better result. I'm >> thinking there's something wrong with the camera. >> >> (And by not working I mean the camera doesn't respond to the power >> switch *at all*. No little beeps, no display, nothing.) > > Does it work if you stick the proper batteries in it? Yes, that's how I know the camera works. It just doesn't seem to be connecting to external power, although it does act sorta flaky when the batteries get low--but it does work (camera beeps, lens extends, display comes alive). It also regularly "forgets" settings (in NOVRAM), like date and time. But for $1 ... -- You were wrong, and I'm man enough to admit it. - a Usenet "apology" |