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    What does the symbol mean?

    Hi, I have a function generator Agilent 33250A, On it output port, it has a symbol like shown below. What does it mean? The function generator has an inner circuit like , The shield is connected to the ground through a resistor and a capacitor, but I really don't see there is any relation...
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    Resistance of double sided adhesive conductive carbon tape

    Hi, Is anyone familiar with conductive tape? I thought conductive tape should have a resistance very small. And the supplier said it has a resistance of less than 5ohms/square. http://www.2spi.com/catalog/spec_prep/cond_adhes-tapes.shtml But I took a measurement today. I use a small part of...
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    Rest in Peace, Kris

    It is really a shock for me to hear that. Really feel bad. Rest in Peace, Kris.
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    An interesting experimental phenomenon related to electric field

    Thank you all the same. The idea of magnetic field is something I didn't pay attention before. Maybe that's the answer.I will keep working on it.
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    An interesting experimental phenomenon related to electric field

    I understand the electron beam is focused using a magnetic lens which is similar to a solenoid with current running through it to produced a magnetic field. Actually I have two years experience with SEM, before I always apply DC voltage to our device, and everything is fine. This is the first...
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    An interesting experimental phenomenon related to electric field

    Thanks for your reply. The largest voltage I use is 15Vpp. Do you mean that this voltage is too small to produce a large enough electric field to deflect electron beam?
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    An interesting experimental phenomenon related to electric field

    Hi, I find an interesting related to electric field when doing experiment. I put a chip which has the following simplified circuit inside Scanning Electron Microscopy(SEM), an electron beam is irradiating on R1. The AC source is isolated from earth by using a capacitor C1 and resistor R3 in...
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    problem encountered when using function generator and oscilloscope

    I am still not clear about how was the 60Hz signal introduced into the close loop. Would you please give me more clue?
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    problem encountered when using function generator and oscilloscope

    I understand this is a special case, only for my situation. I found the diagram of the function generator. I think may be the return path is achieved by using earth as a conductor. Current flows like shown below. Do you think this is reasonable?
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    problem encountered when using function generator and oscilloscope

    "If one of those meters had a ground connection, and you hooked it up to a circuit that is powered from mains with a real ground, you would cause damage." That makes sense. But from the manual of the oscilloscope, it is said "The probe ground lead is at ground potential." I wonder if it is not...
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    problem encountered when using function generator and oscilloscope

    "Otherwise, without a reference, you begin to pick up noise and other random emissions." Are you saying connections in image 2 and 3 have no reference? But I think the since the ground clip is connected to ground directly, couldn't we say in image 2's situation the positive lead has a certain...
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    problem encountered when using function generator and oscilloscope

    What I mean is that, since the ground clip is connected to the ground，I think we can tell the function generator's negative lead has certain potential difference with reference to ground from the last image(Vpp=1.4V). While in the first image, the negative lead is connected to ground directly...
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    problem encountered when using function generator and oscilloscope

    Hi, I observed the following phenomenon when using Oscilloscope(Tekronix TDS 2024B) to measure the output voltage of function generator(Agilent 33250A). 1. connect both leads of function generator to the oscilloscope probe and ground clip, ideal sine wave 10 Hz is observed. 2. Only connect...
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    how to remove PGA socket from the PCB

    Thanks for your answer. I put the PCB on a hot plate for several minutes and then turn over the Pcb, the socket fall down by itself.
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    how to remove PGA socket from the PCB

    Hi Steve, hot air is really a good idea. Thanks.
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    how to remove PGA socket from the PCB

    Hi all, I have a PGA socket soldered on the PCB, like below, I wonder will an ordinary solder sucker (or de-soldering pump) be able to remove the socket from the PCB since the solder points are small?If not, is there any other way I could do it? Thanks.
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    Need help on a socket's PCB footprint

    Hi, I want to put a OTS-16-1.27-04(SOP16) on my pcb, I use eagle cad to design the PCB. I first search the internet and couldn't found any library which contains this component. Then I try to build the component's schematic and footprint by myself. I met a problem when trying to draw the...
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    Need help on design PCB.

    Hi, I have a board in my hand like shown below. First, I want to know is this board a pcb? Because this board has some different feature comparing with common pcb like shown below. I want to make a board which has the same function as the one shown above.The board need to have an array of...
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    Chassis ground

    Hi all, I saw many equipments have the grounding symbol on their chassis,like shown below I was wondering why we need to ground these chassis? I think the ground line coming out of the outlet has already grounded the equipment chassis, why we need to do that again?
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    Ground loop of Agilent 33250A

    I am not quite understand why chassis doesn't form a loop. I think it is the earth connecting the chassis makes a close loop which induce the Ignd. And I have an extra question. Why couldn't the design be simple as the following? What's the benefits of using original design? Thanks.
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