Posts by Olin Lathrop
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...
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 ...
At first glance, your design looks reasonable. I assume D1 and D2 are really supposed to be on opposite data lines, and them both being on the A line is a typo? One thing that sticks out to me is...
At first this sounded like it might be a classic case of forgetting the flyback catch diode across the relay coil. However, now that you've posted a schematic we can see that a diode is built into...
It seems you want to protect a device against power spikes. The power supply is nominally 12 V, but can have spikes up to 79 V with an impedance of 500 mΩ. Two timing values were given, but they ...
What you basically ask for can be done (I've done it), but not all your specific constraints can be reasonably met. The way to measure transmission line impedance is to drive a step onto the trans...
In addition to what Andy said, the DC servo method doesn't add impedance to the signal. Note that in your bottom circuit, the signal with the DC offset removed has an impedance of 1 MΩ at DC. In ...
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...
It's a balance. On one had, we want to be a store of knowledge. It doesn't matter what prompted a particular piece of information to be posted if it serves the long term purpose. We also don't w...
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...
Your proposed circuit will work, but "before the voltage drops significantly" is rather wishy-washy. I would at least use a second meter to measure the current. What you really want to know is th...
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...
Yes, some BOM optimization questions like you mentioned could be on topic. This would include the general techniques for optimizing BOM costs. Getting into specific prices and vendors would be off...
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...
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...
In general, the on/off delay is how long it takes from changing the input until the output starts to do something. The rise/fall time is how long it takes to do the something, once it starts doing...
According to the datasheet that Andy linked to, the chip can be configured for 0 dBm output. With the proper antenna, that is probably good enough for 20 m, but you'll have to test it yourself to ...
Yes, plugging a microphone into a headphone output could possibly damage the microphone. Microphones are designed to work on tiny vibrations and tiny currents. A dynamic microphone will work back...
Summary "Outdated" should be used for "this won't work anymore today", not "we would do this differently today". Detail "Outdated" should be reserved for when an answer is wrong or misleading be...
Can anyone explain the theory behind this pin You have already done so yourself: used to give a common mode stabilization and thereby reduce radiated emissions As far as I know, that is exactly ...
What is a typical value for capacitance of a real inductor? "Typical" capacitance is a useless to design circuits with. It will also vary considerably by inductor size, geometry, and materials us...
What the "appropriate" value of R1 is depends on what you are trying to achieve, which you haven't told us. Will this device be used in bright light, like outdoors, and the LED therefore needs to ...
Those batteries must be for powering electronics that receives commands from your controller or remote. They don't have anywhere near the energy to raise something like the headrest of a normal be...
Your first circuit topology makes sense, although some of the part values are questionable. How the circuit works R37 provides the bias supply for the condenser microphone with a predictable impe...
The main point is that you need thermal symmetry between the two pads of a small package. You want the solder paste to melt at the same time between the two pads. Molten solder has significantly ...
