Display half-wave on Rigol DS1102E

Thread Starter

CROSSBOLT

Joined Dec 9, 2008
21
Sig gen output ~90 vac 182 v pp
Circuit string: resistor 10k, diode 1N4007, resistor 4700
Scope trace chan 1 hooked across sig gen input to string.
Scope trace chan 2 hooked across 4700 ohm resistor.
Pictures inverse order of text.

I know what the chan 2 trace SHOULD look like and that ain't it. I have tried this with different diodes, different freqs. What is next?15798019760911397364273.jpg
1579801752493122698912.jpg
1579801615245-835116510.jpg
 

Thread Starter

CROSSBOLT

Joined Dec 9, 2008
21
I can't see what is connected to what in your pictures.
Circuit string: resistor, diode, resistor.
Chan 1 probe to sig-gen/first resistor junction, probe ground to sig-gen/last resistor junction.
Chan 2 probe to diode/last resistor junction, probe ground to sig-gen/last resistor junction.
 

AlbertHall

Joined Jun 4, 2014
12,344
Circuit string: resistor, diode, resistor.
Chan 1 probe to sig-gen/first resistor junction, probe ground to sig-gen/last resistor junction.
Chan 2 probe to diode/last resistor junction, probe ground to sig-gen/last resistor junction.
Something isn't connected - breadboards do that.
What does the 'scope see on the anode of the diode?
What does the 'scope see on the ground wire of the last resistor (actually on the resistor leg)?
 

Thread Starter

CROSSBOLT

Joined Dec 9, 2008
21
All is connected and verified continuity. No lack of connectivity found in breadboard.
Left to right: 10k res, 1N5399 diode(cathode stripe right), 10k res, .01uf cap to isolate dc from sig-gen output.
L1579813753778-874541178.jpg
 

Thread Starter

CROSSBOLT

Joined Dec 9, 2008
21
Depends upon the purpose of the circuit.
If you just want to observe the rectified half-wave signal, the increase the value of the 4.7k ohm resistor to something like 50k ohm.
THAT is the purpose of the circuit! Previous scope this kind of stuff was slam-dunk easy. This was a familiarization project to train me in using this model. Will try the 50 k ohms and report.
Thanks!
 

Thread Starter

CROSSBOLT

Joined Dec 9, 2008
21
The principle I missed and rediscovered today was the 10X and 1X switch on the probe and on each channel menu. Pretty basic but WE ALL MISSED IT! But thanks for your inputs!
 

Thread Starter

CROSSBOLT

Joined Dec 9, 2008
21
The display above was at 60 hz. Now back to square one at 3 mhz and above to 27 mhz. Already tried different resistors 1k ohm to 1 megohm and different diodes.
 
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