Posts by Olin Lathrop
First let's define what a "Pi filter" is: The name comes from the inductor and two caps forming the shape of the Greek letter Π. These filters are used for EMC compliance because they attenuate hi...
say that materials should be small and focused There are many many theories of how to best present information. Any one or two particular opinions aren't really relevant, especially since there i...
Direct answer How to clean off flux depends on what type of flux was used. Most electronic parts can handle being washed in clean water. In fact, boards often go thru what amounts to an industri...
I have boycotted the SE and neither asked or answered any questions so am happy to have a new home here. I'm glad you're here. You might also want to mention this in your SE profile, and point pe...
FET source-followers are generally less predictable than BJT (bipolar junction transistor, like NPN or PNP) emitter-followers. An emitter follower output is one diode drop below the input. The vo...
The microwave oven uses frequencies near some types of WiFi. The very strong radiation created by the oven is meant to stay inside the oven. However, even if only a small fraction gets out, it co...
First, let's be clear about something. All currents partially take all paths relative to the inverse of the path impedances. It's not an all or nothing function. This "Takes the path of least re...
You generally want complementary NPN/PNP pairs when they are used as opposites of each other in the same circuit. One transistor is usually used with opposite polarity as a mirror image of the oth...
It's not clear what you are really trying to do, but if you're trying to replace the left circuit with the right one, that's a bad idea: The left circuit switches to appear to pass partial volta...
Pi filters are often used to block high frequencies between a device and the power line it draws power from. In such applications, the considerations specifying the inductor include: How much powe...
The short phrase is trying to capture the two broad classes of topics here: Electronic things, like opamps, transistors, microcontrollers, 20 W power supplies, and the like. Utility-scale power sys...
There are four things we can do with bad or poorly written questions. In order of seriousness, these are: Leave a comment. Downvote. Close. Delete. The questions you mention have mostly bee...
Is the answer of 1/c seconds correct It can't possibly be. The question is looking for a time value. "C" is a speed, which has units of distance/time. "1/c" therefore has units of time/distance...
It looks like you've sort of re-discovered a motivation for Fourier analysis. The difference between looking at slope versus frequency content is exactly the difference between time domain and fre...
That circuit doesn't do what you think it does. Here is the circuit in question: The impedance seen at IN is definitely higher at high frequencies, but that is only due to it being artificially l...
What you are asking for is totally unrealistic, and your numbers don't add up. With 10 mH and 80 µF, the resonant frequency is 178 Hz. Getting down to 1 Hz even with 10 mH would require over 2.5 ...
If the TVS truly clamps the "+12V" line to 25 V, then the VGS of Q1 can't exceed 25 V. However, if you want to limit the gate voltage, limit the gate voltage. A Zener between gate and source guar...
The electrodes electrically connect to the skin in order to pick up tiny signals produced by the heart muscles. Electrically you're a bag of saltwater. Your skin (the bag) has a relatively high r...
It's a current limiter, not eliminator. The current is always supposed to flow, but be limited at startup to avoid high inrush current. All the relay does is short out R103 when activated. The r...
Firstly, is this calculation for power dissipation correct? P = (I2 * R) + (I * V * (t_on+t_off)/2 * f) = 0.517 W Not completely. There are two separate parts that need to be considered. I2RDSO...
The expansion of the conductors is the least of your problems. The real issue is the effect of excessive temperature on the insulators. The plastic in the cable has three electrical functions: T...
I've heard that input signals to digital circuits should be "de-bounced", at least sometimes. What is de-bouncing? Why is it needed? When is it needed? What is bouncing around in the first place?
in my engineering curriculum .. I never found a diode in a mosfet symbol Then you should ask for your tuition back, or perhaps the institution should want their diploma back. but in datasheets ther...
If I have a filter stage between an antenna and an LNA, wouldn't I want the load impedance(input to the LNA) to be large with respect to the source(antenna) in order to not attenuate the signal ev...
A "normal" digital output actively drives both high and low. Open drain or open collector outputs only actively drive low, and go to high impedance when the signal is meant to be high. Some reaso...
