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Negative ground in series with Positive ground

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walters

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negative ground power supply

Does a circuit with Positive ground output negative voltages? negative DC offset? waveforms below the zero reference?

Does a circuit with Negative ground output Positive voltages? Positive DC offset? waveforms above the zero reference?
 

ptmsl

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d.c battery positive earthing

Positive ground means that the positive output of the DC power supply is grounded that it is used as reference and probably connected to the chassis. The outputs of this device are either DC coupled and of course negative in respect to "ground" or AC coupled so that they have no DC offset. If the output is AC coupled (via a capacitor) then the output has the DC offset of the device that it connects to.
The opposite stands for negative ground. The output is either positive with respect to ground or AC coupled.
Most circuits are negative ground (earth) except telecom circuits that use a 48V positive earth supply.
 

walters

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dc voltage positive to ground

Thanks for the information

Does a circuit with Positive ground output negative voltages? negative DC offset? waveforms below the zero reference?

Is the AC voltages negative? would the AC waveform have negative voltages
 

aryajur

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dc positive earth

Ground is just the way of indicate the reference node with respect to which voltage measurements are made. So if you have a simple DC battery, if you decide to make the positive terminal as the common ground terminal in the circuit then of course the negative terminal is at a negative DC offset with respect to ground. On the other hand if you decide to make the negative terminal as the common ground terminal in the circuit then the positive terminal is at the positive DC offset with respect to ground. An AC source is an alternating source so if you pick either one of the nodes as the reference the other node goes both positive and negative with respect to it.
 

ptmsl

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positive ground dc power

Ground is always the reference point of the circuit and usually the return path for the output curents. If you have a positive ground the output can only be negative with respect to ground for DC outputs. If the output is AC and AC coupled then the DC offset of the output is set by the load and is not necessarily negative. For example if the signal is coupled to the output with a capacitor and there is a resistive load to ground connected at the output then the AC signal will have 0V DC offset and will take both negative and positive values but always around ground reference.
 

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