B
BrianP
- Jan 1, 1970
- 0
Hi,
I have a harebrained scheme to create a 12 Volt, wide angle flashlight
with a dimmer. I want to be able to go from the glow of a firefly to
that of an aircraft landing by adjusting a dial or slider.
I am a Scientist (mechanical engineer) and Photographer and am often
called upon to shoot in cave dark conditions. In bright light
conditions, my camera (Nikon D100) uses the old subtract and add
algorithm to find the point of maximum contrast to focus. In dark
conditions, it falls back on the much less accurate infrared beam trick
and the results are noticeably less consistent and accurate.
I want to put a 12 Volt, wide angle, halogen bulb on a dimmer and be
able to illuminate my subject(s) with or without blinding them in the
process. It will also give me a second, offset light source to reduce
shadows and shine from the flash. I need power in roughly the 10 - 100
Watt range.
Another, extremely useful feature would be to have the lights
automatically turn off as soon as the main flash strobes. I have a
photoelectric flash attachment which flashes a slave flash when it sees
the main flash go off (or when you pass your hand in front of the
detector and it senses a spike in illumination). This apparatus sends a
voltage telling the slave flash to flash. Surely, this same signal could
be used to turn a circuit off.
Ideally, I would get ready to take a picture, press a button to turn the
secondary light(s) on, dial in the desired illumination, take the flash
photo and have the light of the main flash turn off the secondary lighting.
I checked Radio Shack and all they have are either 120 V AC dimmers or a
3 W, DC rheostat. I want a time division switch which keeps the
connection closed for between 1% and 99% of the time. Ideally, it would
run off of the 12 V supply it is controlling and not use the same amount
of power all of the time by burning some of the juice off as heat and
the rest as light. I am thinking about a time division circuit
connected to a capacitor to cushion the sudden blasts of on-time voltage.
Any brilliant ideas?
Brian
I have a harebrained scheme to create a 12 Volt, wide angle flashlight
with a dimmer. I want to be able to go from the glow of a firefly to
that of an aircraft landing by adjusting a dial or slider.
I am a Scientist (mechanical engineer) and Photographer and am often
called upon to shoot in cave dark conditions. In bright light
conditions, my camera (Nikon D100) uses the old subtract and add
algorithm to find the point of maximum contrast to focus. In dark
conditions, it falls back on the much less accurate infrared beam trick
and the results are noticeably less consistent and accurate.
I want to put a 12 Volt, wide angle, halogen bulb on a dimmer and be
able to illuminate my subject(s) with or without blinding them in the
process. It will also give me a second, offset light source to reduce
shadows and shine from the flash. I need power in roughly the 10 - 100
Watt range.
Another, extremely useful feature would be to have the lights
automatically turn off as soon as the main flash strobes. I have a
photoelectric flash attachment which flashes a slave flash when it sees
the main flash go off (or when you pass your hand in front of the
detector and it senses a spike in illumination). This apparatus sends a
voltage telling the slave flash to flash. Surely, this same signal could
be used to turn a circuit off.
Ideally, I would get ready to take a picture, press a button to turn the
secondary light(s) on, dial in the desired illumination, take the flash
photo and have the light of the main flash turn off the secondary lighting.
I checked Radio Shack and all they have are either 120 V AC dimmers or a
3 W, DC rheostat. I want a time division switch which keeps the
connection closed for between 1% and 99% of the time. Ideally, it would
run off of the 12 V supply it is controlling and not use the same amount
of power all of the time by burning some of the juice off as heat and
the rest as light. I am thinking about a time division circuit
connected to a capacitor to cushion the sudden blasts of on-time voltage.
Any brilliant ideas?
Brian