I'm trying to recreate a 50 year old lighting effect circuit, and I'm having a very difficult time with a photocell. I'm hoping someone can help me figure out what numbers I should be looking for.
The original component is a Clairex CL5M4 CdSe photoresistor (which is coupled with 5 LEDs which flash at "random" intervals.) The basic component data is readily available online, but I cannot figure out how to apply that to a DigiKey or Mouser search result.
The important stats are:
1: Photocell resistance is often given @ 10 lumen. Should the above numbers be divided by half or multiplied by two? (My thinking is that the light would appear brighter as the cell moves closer to the source, so multiply by two)
2: In most datasheets, illuminated resistance is given as a range, ie. "0.5 ~ 17kOhms @ 10 lumen". I don't understand how this range applies to the single resistance value given for the original component.
3: Finally my choices become very limited when I select 250V. I know to choose a component rated higher than the highest possible voltage, but I don't actually know what voltage is being applied to the photocell. How can I use a multimeter to measure the voltage applied to the photocell? (I'm worried about damaging an irreplaceable 50 year old device.)
Any advice would be greatly appreciated!
Here's a video of the original circuit in action if anyone is curious. The photocell and LED array are on the left inside a black plastic canister. (I'm sure that today there's a better way of achieving the random resistance created by the photocell/LED combination, but I want to try recreating it as designed first.)
The original component is a Clairex CL5M4 CdSe photoresistor (which is coupled with 5 LEDs which flash at "random" intervals.) The basic component data is readily available online, but I cannot figure out how to apply that to a DigiKey or Mouser search result.
The important stats are:
Illuminated resistance 1.5k @ 2ft-candles (≈ 21 lumen)
Min dark resistance 400k @ 2ft-candles (≈ 21 lumen)
Max voltage 250V
1: Photocell resistance is often given @ 10 lumen. Should the above numbers be divided by half or multiplied by two? (My thinking is that the light would appear brighter as the cell moves closer to the source, so multiply by two)
2: In most datasheets, illuminated resistance is given as a range, ie. "0.5 ~ 17kOhms @ 10 lumen". I don't understand how this range applies to the single resistance value given for the original component.
3: Finally my choices become very limited when I select 250V. I know to choose a component rated higher than the highest possible voltage, but I don't actually know what voltage is being applied to the photocell. How can I use a multimeter to measure the voltage applied to the photocell? (I'm worried about damaging an irreplaceable 50 year old device.)
Any advice would be greatly appreciated!
Here's a video of the original circuit in action if anyone is curious. The photocell and LED array are on the left inside a black plastic canister. (I'm sure that today there's a better way of achieving the random resistance created by the photocell/LED combination, but I want to try recreating it as designed first.)