White LED on 1.5 v Supply

2 White LED on 1.5 v Supply

2-white-led-on-1_5-v-supply
Parts
T1 – BC338
R1 – 2.7 K
C1 – 10 n
D1,D2 – Super bright LED
Transformer – 60 T, 40 T
S1 – On/off Switch
Battery 1.5 V

White LED Flasher

white-led-flasher
Parts
T1 – BC338
T2 – 2N2222
R1 – 2.7 K
R2 – 47 R
R3 – 330 R – 1K
C1 – 10 n
C2 – 100
D2 – 1N4148
Battery 1.5 v

USB Reading Lamp

USB reading lamp is powered using USB port. The USB port provide 5 v and 100mA which is sufficient for this circuit. Cut the one end of the USB cable and use RED(pin1) and Black(pin4) for 5v positive and negative respectively.

 

USB lamp
Parts
  1. c1,c2 – 100 mF 25 v
  2. Zener diode – 4.7v 400m
  3. R1- 220 r
  4. R2- 100 r
  5. T1 – SL100
  6. White LED – 5 nos.
  7. USB Cable