Article
PWM Control for LED Flashlight
anti-dazzle dimmer
This circuit was designed for use with an LED flashlight of the sort used by pedestrians, in particular those walking at night time. Once your eyes have become accustomed to the darkness, the brightness of the lamp at full power is too great and can actually impede your vision. And of course there are other applications where it is useful to run an LED at reduced power.
Materials
Gerber file
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PCB
Component list
Component List
Resistors
Default: SMD1206, 1%, .25W
R1, R9 = 12kOhm
R2, R5 = 220Ohm
R3 = 10kOhm
R4 = 27kOhm
R6 = 36kOhm
R7 = 51kOhm
R8 = 100Ohm
Capacitors
Default: SMD1206
C1 = 10nF*
C2, C6 = 100nF
C3 = 10nF
C4, C5 = 10µF 63V radial
Semiconductors
IC1 = ATtiny45-20SU (SOIC8)
IC2 = AP1117E33G-13 SOT-223)
D1 = BAS70* (SOT-23)
T1 = IRLL2705PBF (SOT-23)
Divers :
K1,K3 = 2-pin pinheader
K2 = 6-pin (2x3) pinheader
K4 = 3-pin pinheader
K5 = 4-pin pinheader
S1 = pushbutton
S2 = switch, on-off-on, center detent
PCB # 140019
*see text
Resistors
Default: SMD1206, 1%, .25W
R1, R9 = 12kOhm
R2, R5 = 220Ohm
R3 = 10kOhm
R4 = 27kOhm
R6 = 36kOhm
R7 = 51kOhm
R8 = 100Ohm
Capacitors
Default: SMD1206
C1 = 10nF*
C2, C6 = 100nF
C3 = 10nF
C4, C5 = 10µF 63V radial
Semiconductors
IC1 = ATtiny45-20SU (SOIC8)
IC2 = AP1117E33G-13 SOT-223)
D1 = BAS70* (SOT-23)
T1 = IRLL2705PBF (SOT-23)
Divers :
K1,K3 = 2-pin pinheader
K2 = 6-pin (2x3) pinheader
K4 = 3-pin pinheader
K5 = 4-pin pinheader
S1 = pushbutton
S2 = switch, on-off-on, center detent
PCB # 140019
*see text
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