# Ac to dc ground

Discussion in 'General Electronics Chat' started by frankinaround, Jun 28, 2012.

1. ### frankinaround Thread Starter New Member

May 14, 2012
15
0
Hi.

Say I have an ac lead from transformer to a resistor to the other transformer lead. The oscillscope will se a sine wave. But what happens to the sine wave if one ac lead goes to the resistor and then to a dc negative (say if ran thre ac threw a bridge and ran the resisyor in parrallel with an ac lead amd the bridge to the bridges negative dc)

What would happen to the sin wave? Would it be half peak to peak? Would it look the same?

2. ### WBahn Moderator

Mar 31, 2012
18,085
4,917
What is "an ac lead"? Is it a wire that is capacitively coupled to something?

When you talk about two transformer leads, are these the leads on the same winding? different winding?

You're painting a very confusing picture. Could you throw something together in way of a schematic? Doesn't have to be fancy. Use Paint and just use labeled boxes for the components.

3. ### frankinaround Thread Starter New Member

May 14, 2012
15
0
Basically i tried several bridge rectifiers and im getting the same result. When i connect my scope from one of the ac terminals to the negative dc the bridge is outputting, im getting a half rectified sine wave that right before its voltage hits 0 has a weird indentation then hits 0. Im wondering why.

4. ### WBahn Moderator

Mar 31, 2012
18,085
4,917
A picture is worth a thousand words.

DRAW A PICTURE!

strantor likes this.
5. ### frankinaround Thread Starter New Member

May 14, 2012
15
0

I want to know why in graph A, the part of the graph that hits 0 moves up and down when the trig is less then or equal to 3.6 volts

I also want to know in graph B why are there the 2 volt humps ?

also, why dont the peaks look the same as the ac input wave thats going into the bridge rectifier? the ac input wave is much smoother, but these peaks look alot longer and flatter then the ac input waveform. (didnt draw because it looks like a normal ac waveform)

May 14, 2012
15
0
7. ### WBahn Moderator

Mar 31, 2012
18,085
4,917
You need to post them in such a way so that we don't have to register with Google or anyone else in order to see them. Here's an idea -- attach them to your post so that they are archived as part of the AAC database.