Schematics of delabs

This was done in my early days, i have upgraded it, it ought to work, reduce the number of transistors to make it less sensitive, also a lower value in place of 10M will reduce its sensitivity, use clamping diodes to protect. BD139 is used to drive the… more »

The Reed Relay based Float Switches are used in Automobiles and even corrosive and volatile fluids. This can also be used to indicate level of water or operate pumps. The reeds are hermetically sealed in glass, Like the Incandescent bulb. The signal… more »