Let's talk about Lighting
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- daniel_reetz
- Posts: 2812
- Joined: 03 Jun 2009, 13:56
- E-book readers owned: Used to have a PRS-500
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Re: Let's talk about Lighting
btw, that behavior might be consistent with an "audio taper" pot or a "log" pot. I'll try it on my own setup as soon as I can.
Re: Let's talk about Lighting
I was using the 1.7amp PSU, I'll try the 3 amp tonight.
Also, I think I'd be just as happy with a off-med-full setup. Off could be a switch on the PSU to the buckpuck, and full would just be a switch (I think if there's nothing/open switch between ctrl and ref you get full bright, twist them together/closed switch no light at all?). I like the idea of having a "working brightness," enough to turn the pages and get ready, and a "capture brightness," full I guess, so I'll try a few different resistors like you said.
Please tell me if the following makes sense, realizing the resistors could be swapped out until they add up to 5k ohms which would be full anyway:
Two levels (med-full):
Low beam:
ctrl--->closed switch--->1k ohm resistor--->ref
Full beam, open switch.
Three levels (low-med-full):
Low:
ctrl--->closed switch--->1k ohm resistor--->closed switch------------->ref
.................................................--->2k ohm resistor-----------^
Med:
ctrl--->closed switch--->1k ohm resistor--->OPEN switch------------->ref
................................................. --->2k ohm resistor-----------^
Full beam, open first switch.
Also, I think I'd be just as happy with a off-med-full setup. Off could be a switch on the PSU to the buckpuck, and full would just be a switch (I think if there's nothing/open switch between ctrl and ref you get full bright, twist them together/closed switch no light at all?). I like the idea of having a "working brightness," enough to turn the pages and get ready, and a "capture brightness," full I guess, so I'll try a few different resistors like you said.
Please tell me if the following makes sense, realizing the resistors could be swapped out until they add up to 5k ohms which would be full anyway:
Two levels (med-full):
Low beam:
ctrl--->closed switch--->1k ohm resistor--->ref
Full beam, open switch.
Three levels (low-med-full):
Low:
ctrl--->closed switch--->1k ohm resistor--->closed switch------------->ref
.................................................--->2k ohm resistor-----------^
Med:
ctrl--->closed switch--->1k ohm resistor--->OPEN switch------------->ref
................................................. --->2k ohm resistor-----------^
Full beam, open first switch.
- daniel_reetz
- Posts: 2812
- Joined: 03 Jun 2009, 13:56
- E-book readers owned: Used to have a PRS-500
- Number of books owned: 600
- Country: United States
- Contact:
Re: Let's talk about Lighting
here's how i am imagining this thing
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Re: Let's talk about Lighting
That's much nicer. Depending on traffic and inlaws, I'll have it done tonight.
Re: Let's talk about Lighting
I have now tried 1K ohm and 3.3K ohm resistors and still only get dazzling or blinding, no real reasonable work light intensity. I'd appreciate anyone else with home made LED set up see how low will they go. I'll also call LED supply tomorrow and ask what I should expect.
Edit:
I think I ought to go play with the wooden parts again. I've had enough of these electrical bits.
Edit:
I think I ought to go play with the wooden parts again. I've had enough of these electrical bits.
- daniel_reetz
- Posts: 2812
- Joined: 03 Jun 2009, 13:56
- E-book readers owned: Used to have a PRS-500
- Number of books owned: 600
- Country: United States
- Contact:
Re: Let's talk about Lighting
I'm gonna get my buckpuck-powered rig out and experiment now. I'll post back here with results.
- daniel_reetz
- Posts: 2812
- Joined: 03 Jun 2009, 13:56
- E-book readers owned: Used to have a PRS-500
- Number of books owned: 600
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- Contact:
Re: Let's talk about Lighting
Alright, so I just checked the circuit out with a 10k pot (just what I had laying around). I'm going to post a video in a minute (UPDATE: about an hour, blasted slow uploads!), but the lesson learned is that values around 250-500ohms are where the dimming happens. As a result, the total dimmable area available to you on a 5 or 10k pot is very small. You can try some small-value resistors, or a 1K pot (so that the 300-500 range comprises more of the available turning radius of the pot) to get down to the values you're looking for.
- daniel_reetz
- Posts: 2812
- Joined: 03 Jun 2009, 13:56
- E-book readers owned: Used to have a PRS-500
- Number of books owned: 600
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Re: Let's talk about Lighting
Daniel:
Earlier in this thread you showed a photo of two lever switches with rollers. I'm sure that one was to control the low-high levels of the lights. What was the purpose of the second switch?
Thanks
Earlier in this thread you showed a photo of two lever switches with rollers. I'm sure that one was to control the low-high levels of the lights. What was the purpose of the second switch?
Thanks
- daniel_reetz
- Posts: 2812
- Joined: 03 Jun 2009, 13:56
- E-book readers owned: Used to have a PRS-500
- Number of books owned: 600
- Country: United States
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Re: Let's talk about Lighting
The second switch is to trigger the cameras for the system described in this thread.