19
edits
User:Mentar/LED lighting proposal: Difference between revisions
From London Hackspace Wiki
User:Mentar/LED lighting proposal (view source)
Revision as of 18:17, 2 January 2016
, 2 January 2016PWM and UV
(Updated c-channel) |
ChristianJ (talk | contribs) (PWM and UV) |
||
| Line 38: | Line 38: | ||
=== Implementation === | === Implementation === | ||
At 3.5V each LED consumes around 750ma. 5 LEDs in series would need 17.5V across them. We need 3 of these arrays to make up 15 meaning that we have a current draw of 2.25A for a total of 39.375W. Which is well within what even my weak 60W X220 thinkpad PSU can deliver. | At 3.5V each LED consumes around 750ma. 5 LEDs in series would need 17.5V across them. We need 3 of these arrays to make up 15 meaning that we have a current draw of 2.25A for a total of 39.375W. Which is well within what even my weak 60W X220 thinkpad PSU can deliver. | ||
=== Comments === | |||
Sounds good to me. Good that you didn't include dimming functionality based on pulse-width modulation: I really dislike LED lights based on low frequency PWM (100 Hz or so), it can be noticed easily in many situations and makes those worse for me than gas discharge lamps (those also might trigger migraine in some people?). With proper DC and no PWM, though, they will be better than gas discharge lamps. (BTW I'm still planning to create a (rather high frequency and low-pass filtered) pulse based circuit to create adjustable DC, if I ever get around implementing that I'll tell.) | |||
Another thing to keep in mind is that some white LEDs use ultra-violet light emitting crystals to get their phosphor to light up; those may need an UV blocking filter to make them eye safe (even if their casing blocks some UV it might not necessarily be enough for the amount used for room lighting?). Alternatively stay with blue crystals. [[User:ChristianJ|ChristianJ]] ([[User talk:ChristianJ|talk]]) 18:17, 2 January 2016 (UTC) | |||
