Water Level Indicator Using Simple Transistors

 

Components Required

• BC548 transistors-Q1,Q2,Q3,Q4
• Resistors R1,R2,R3,R4-2.2kohms
• R5, R6 ,R7 – 100 ohm
• Led – Red(LED3) , Green(LED1) , Yellow(LED2)
• Metal Contacts – M1,M2,M3,M4.