Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

wrong measurment with PCB circuit

Status
Not open for further replies.

tanzil_dhk

Advanced Member level 4
Joined
Aug 9, 2006
Messages
109
Helped
4
Reputation
8
Reaction score
0
Trophy points
1,296
Activity points
1,924
I fabricated a PCB board first time and used trace width of 20 mil for power traces and 10 mil for all others. When i check the circuit with dc input voltage (ex:50 mv- 600 mv) everything is perfect.
When i connect it to a real input (also a dc potential in the same range, ~30 uA current), the circuit receive signal much lower than original.Other parts of the circuit are working fine, just i am receving very low signal as soon as it is connected to circuit input.
Can it be due to the trace width. Or if you have any other idea or suggession please help.

NB: A little more about my circuit, the input pass through RC filter and then amplifier. The filter has nothing to do with the low signal, since i am getting the low signal even before filter. I had already been using same circuit with sholdering on veroboard, so the problem is not related to circuit design, i think .
 

kabaleevisu

Advanced Member level 2
Joined
Apr 14, 2010
Messages
615
Helped
85
Reputation
170
Reaction score
81
Trophy points
1,308
Location
Chennai,India
Activity points
4,507
Hi,
from my point of view it is not related to PCB trace width.(if your board may be single side board it may be get,because for single side you have set the trace width 40 mil )better check the circuit once again.
 

tanzil_dhk

Advanced Member level 4
Joined
Aug 9, 2006
Messages
109
Helped
4
Reputation
8
Reaction score
0
Trophy points
1,296
Activity points
1,924
Thanks for quick reply....Its a single side board. I designed the PCB board and set the input trace width to 10 mil. So you mean it should have benn 40 mil??
Also is not it surprising the circuit works fine with a dc supply of same range without any problem.
 

marce

Advanced Member level 5
Joined
Feb 23, 2010
Messages
2,008
Helped
621
Reputation
1,242
Reaction score
606
Trophy points
1,393
Location
UNITED KINGDOM
Activity points
13,906
Do you mean the DEC voltage is dropping from the power supply to the devices, a little diagram and more explicit on what the signal is would help.
 

tanzil_dhk

Advanced Member level 4
Joined
Aug 9, 2006
Messages
109
Helped
4
Reputation
8
Reaction score
0
Trophy points
1,296
Activity points
1,924
Yes, the dc volage applied in power supply can perfewctly be measured and as i said the if the source of input is from from a dc supply no problem can be observed. I have attached the circuit fr convenience. its simply a filter plus amplifier.
The signal i am trying to measure come from a solution measured vs two electrode. Its quite similar to the battery.
 

Attachments


Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top