how to connect to ADC

[jimkess]

i have the following circuit, where there is two wires coming out and one is connected to +V of battery. How do i connect these two wires to the ADC? I know one output wire should be grounded but which one? i understand the clk and the hold.

 

[KlausST]

Hi,

unclear what you expect the cricuit should do.
Unclear what value or behaviour you want to measure.

Usually with single power supplies the negative side is GND.

GND is just a name for a signal that acts as reference for voltage (measurement)

****
in detail:
the open capacitor connection on the left side. What is it´s signal? and where is it referenced to?

collector:
Without any power supply there will be nothing.
If you want V1 to be the power supply for the bjt, then you need at least a current limiting device (in simplest case a resistor) connected to plus of supply and collector.

V1:
I assume you drew the schematic. Why did you draw V1?

ADC:
It is a single ended input ADC. So it measures the voltage with respect to it´s GND. In your simulation there is no GND connection, but in the real IC there is a connection.
Therefore I assume you need to add a GND symbol as measurement reference point.


Klaus

 

[jimkess]

hi,

the input signal is audio signal, which passes into the capacitor, transistor amplified then the signal arrives at the collector. At this point, yes, the transistor needs power. so actually the o/p wires are connected to an audio jack. So one end of audio jack is connected to +V1 and the other is connected to the collector. There is audio signal at the jack, i tested. But then instead of connecting to audio jack, i wanted to view the audio signal so i connected it to an ADC. The ADC signal is then the audio signal.....as you surely understand from this point on.

however, as i viewed the signal it seems like it is riding on the +Vcc DC signal. This was obtained when the collector end wire was connected to the gnd of ADC referenced gnd and the +V1 of battery was connected to the ADC analog input. I am not sure if this is to be expected and it is certainly right since it is what was observed.

but the question is the confusion: at this point, i think the audio signal is riding whatever the dc supply voltage of ADC is. i think reversing the situation, that is connecting collector wire to the analog input of ADC and connecting the +V1 of battery to the gnd ref to ADC i get nothing or same signal riding on the DC signal(i forgot, i have to test again).

Anyway, the signal at the output is just audio signal and I wanted to connect to the ADC. The battery V1 side is creating the confusion.