Alan W
Well-known member
Am just starting to plan a General Tao, and have a few questions about the LDRs. First, do these get black heat shrinked with their LEDs? This is what I am used to doing, but have seen references in phasers, etc. that suggest leaving them bare (as long as the enclosure is fully light proof).
If they need to be dark, it would be easy for me to design and print little clamshell enclosures for them—and I’m happy to share the stl files with anyone who’s interested.
Second, are there specific tolerances for the LDRs, beyond the part no. specification? I could see making up several pairs of “vactrols” and then matching them at various voltages, if this would be beneficial.
But this then leads me to a more general question, about matching LDRs—if there is a protocol that is typically used to sort them? I’ve been using a fixture I printed to hold the LED and LDR at a given distance, and running 3 different voltages into the LED and using the readings for matching purposes. My guess was to go with barely visible glow, low glow, and just under VF brightness. I’ve been getting ~ 40K, 2K5, and 225R (all generalizations) as my typical readings, with a few that get tossed. I do wonder how critical the speed of resistance change is, and that becomes much more difficult to measure. This is all being done mainly to try and make the dual phaser as symmetrical as possible, which may or may not make a difference—hey, this is a purposeful time suck, isn’t it?
If they need to be dark, it would be easy for me to design and print little clamshell enclosures for them—and I’m happy to share the stl files with anyone who’s interested.
Second, are there specific tolerances for the LDRs, beyond the part no. specification? I could see making up several pairs of “vactrols” and then matching them at various voltages, if this would be beneficial.
But this then leads me to a more general question, about matching LDRs—if there is a protocol that is typically used to sort them? I’ve been using a fixture I printed to hold the LED and LDR at a given distance, and running 3 different voltages into the LED and using the readings for matching purposes. My guess was to go with barely visible glow, low glow, and just under VF brightness. I’ve been getting ~ 40K, 2K5, and 225R (all generalizations) as my typical readings, with a few that get tossed. I do wonder how critical the speed of resistance change is, and that becomes much more difficult to measure. This is all being done mainly to try and make the dual phaser as symmetrical as possible, which may or may not make a difference—hey, this is a purposeful time suck, isn’t it?
