DC 5V input to DC 7.5V to 12V

[guclusat]

IC1: 555 timer
Q1: BC548, NPN transistor
D1-D4: 1N4148 diodes
C1, C3: 10uF 25V Electrolytic
C2: 0.001uF 50V Ceramic capacitor
0.25W 5% Resistors
R1, R2: 1K
R3: 4.7K
R4: 220 ohms
P1, P2: 100K to 1M potentiometer