Posts by Olin Lathrop
As far as I know from my own experience, CAN and at least 10 Mbit twisted pair ethernet both care about the impedance between the two wires, not so much from each wire to some common ground. This ...
It's really not clear what exactly happened in that video. We see someone slinging a hook over the power line, then we see a white picture. We don't know what the cable was made of and where the ...
I guess it would work. I have used electrodes on a PCB to detect whether water level got high enough to turn on a sump pump. It worked, although it hasn't been installed very long. In that case ...
Impedance Yes, impedance is "extended" resistance. Impedance is really a complex value, with resistance it's real part. The imaginary part represents pure inductance or capacitance (with opposit...
At 1 MHz it's probably not transmission line effects. It's not clear from your question whether the SPI bus works on the main board with the expansion board connected, but not when it's not connec...
First clarify where this leakage current will be flowing. You seem to think that some parts of the solar panel will generate a small current thru the rebar into the ground, but where is the closed...
One possibility is to use a transformer. The power input can then come from across the plus and minus input power. The output can be referenced to whatever you like, which in this case would be g...
I don't know what the book has in mind, but your first point is the main reason I would want to filter out the high frequencies with passive analog components. Low noise and low distortion are imp...
Note that open-circuiting an inductor "resets" the magnetic field instantly. The downside is that this also generates infinite voltage for that infinitely small time. Infinite voltage is obviousl...
Unfortunately the frequency legend on your graphs are too small to see, so we don't know how the left and right graphs relate to each other. However, what is certainly going on in the left graph i...
You are asking about this circuit and want to know whether this is a radio transmitter/receiver system. No, it's not. First, everything is DC. There is no radio propagation at DC (0 frequency...
As far as I know, there is no standard format, at least not one supported by many packages. What I would look for instead is the existence of converters. Check the ability of a tool to export or ...
I am not familiar with that standard specifically. However, usually standards will have some multiple for effective separation distance inside a PCB versus across air. One standard I remember spe...
I'm trying to drive a relay according to a 5 V digital signal, using this circuit: It works for a while, but then the transistor fails. When I replace the transistor, it works for a while again, ...
I was hiking around the Berkshires in western Massachusetts yesterday, and came across this metal panel where some power lines were crossing a ridge: The panel is a few meters wide, and appe...
Lower ESR can sometimes be a reason, as you say. However, most of the time the advantage is a wider frequency range over which the combined capacitor has low impedance or low dissipation. The fre...
PCB antennas are not designed by electrical engineers, but guys with pointy hats and wands They use trial and error after starting with the result of some mystic ritual including lots of mumbling ...
Repair questions can be on topic if it's about the underlying electronic principles. Just "How do I fix this?" is off topic. There is little wiggle room for trying to repair a consumer device tha...
Apparently you want to measure the current/voltage relationship of a tunnel diode. The tricky part is that the voltage isn't unique for currents over parts of the range. From your question: No...
Here is a basic diagram of the power feed to your house, according to what the power company said they found: R1 represents the additional series resistance due to the cable being corroded. R2 re...
It's not totally clear from just the verbal description, but it seems the real question is when/if signal and chassis ground should be connected. If the circuit is not intended to be truly isolated...
Yes, this is safe, but you do have to consider the layout carefully. You have to make sure that nothing conductive gets between the pads of each resistor. For this high voltage safety purpose, you...
No, I have not seen this circuit before, and don't know what source you may have gotten it from. However, I'm not sure that really matters. I don't know what exactly you are trying to teach, but m...
First, let's redraw the circuit a little more clearly, with logical flow left to right. This also protects the answer from possible changes to the question. As you say, Q1 is a switch to control ...
The reason the transistor is dying is because you didn't put a flyback diode across the relay coil. Relay coils have significant inductance. This means the current can't change instantly without t...
