the diff between ground and -ve

Hello i am abdallah

i hope every one is ok
i would like to ask an important question

1) what is the diff between ground and negative terminal of the dc power supply.
2) in the inverter when the input is "1" then the out is "0".......this output means that there is no electricty at all....... or there is a negative supply althought it is weak.
......................................
IN FACT

i would like to use a digital volume control that in triggered by a ground terminal(as the circuit drawing say) and i would like to trigger it by the output of the IC 555 (timer) that supplys a positive power supply ....i thoght about connecting an inverter......but i found that when the timer's output is "0" the inverters gives the volume control postive power supply so in can be damaged what can i do?

please help me
thank you

There are many grounds. One is the safety ground/earth of the power lines. It is connected to the earth. In circuits there is a conductor which all of the signal levels and power supply levels are referenced to. This is called circuit ground.

The logic levels you mention are specific voltages that can source or sink currents and not change level (much).

1. Ground in circuit differnce -Vcc or -Ve is Nigative Voltage
2. When used in Logic circuit '0' or '1' , Pulse Logic signal You have Logic '1' is 5 V
and Logic '0' is 0 V TTL Logic
3. When used Pulse Logic have pole +5V is Logic '1' and -5 is Logic '0'

THANK YOU ALL


but i would like to ask you can i use an NPN switch transistor



1)the collector to the -ve power
2)the emitter to the ic "trigger pin"
3)the Base to the output of the IC 555

thanks

abdallah