No flash in the pan
By Martin Ossmann (Germany)
A PC case with a side window gives plenty of opportunities for pimping the machine out with visual
effects. Stand out from the crowd with the fan stroboscope circuit described here: based on an Atmel
microcontroller, it drives an LED in such a way as to make the vanes of the fan seem to stop, turn slowly
backwards or forwards, or suddenly change position.
Resistors
R1 = see text
R2 = 100kOhm
Capacitors
C1 = 100nF
C2 = 1000µF 16V
C3 = 10µF 10V
C4,C5 = 22pF
Semiconductors
D1 = BAT43
D2 = 1N4007
D3 = power LED (see text)
IC1 = ATTiny2313-20PU, programmed, Elektor # 100127-41
IC2 = 78L05
T1 = IRLU120N (International Rectifier)
Miscellaneous
K1 = 3-pin pinheader
K2 = 4- pin pinheader
JP1= 18-pin (2x9) DIL pinheader with Jumper
X1 = 20MHz quartz crystal
PCB # 100127-1
More Download and watch here
PCB PDF
Article PDF
 Software
Relevant websites
www.youtube.com/user/ossimodding
www.eastera.com.cn/data/ES211-ENb_a.pdf
www.melexis.com/Assets/US890US891_DataSheet_4851.aspx
www.nidec.com/fanpdfs/t92t200901.pdf
www.formfactors.org/developer%5Cspecs%5C4_Wire_PWM_Spec.p
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