Down to Ground

[krishtriram]

Dear All,

Kindly explain me the difference bet earth ground,signal ground and chasis ground

 

[isaacj]

Earth ground: It's just what it sounds like. The electrical potential of the Earth. Pound a metal stake in the ground and it will be your terminal for Earth ground.

Chassis ground: The electrical potential of the frame or box that contains a device. Obviously it will be made of a conductive material. For a computer, it would be the case.

Signal ground: This one's a little trickier. It's an arbitrarily chosen (by the circuit designer) point in any given circuit assumed to have zero electrical potential (0 volts). It's useful for making measurements in a circuit.

The black lead of a power supply is typically the ground lead. In a schematic it's designated by the symbol that looks like an inverted "christmas tree".

 

[bryan]

Why is it that sensitive circuitry can be damaged if it is connected to chassis ground as opposed to signal ground. ??