Simple circuit - Page 1
Forum section: electronics / beginners

author: lilmantis
author_rank: Contributor
timestamp: July 28, 2017, 06:38:26 pm
content: Is this circuit from AoE? I do not remember what it was supposed to be.

author: danadak
author_rank: Super Contributor
timestamp: July 28, 2017, 10:05:32 pm
content: AoE = Age of Empires ?What is/does AoE stand for ?Regards, Dana.

author: Zero999
author_rank: Super Contributor
timestamp: July 28, 2017, 10:45:05 pm
content: Quote from: danadak on July 28, 2017, 10:05:32 pmArt Of Electronics?No, I've not seen that schematic before. I doubt it's anything useful. It's probably a model for something.

author: MrAl
author_rank: Super Contributor
timestamp: July 29, 2017, 02:39:08 am
content: Hi,You want to calculate the inductance of the two wires or something?

author: lilmantis
author_rank: Contributor
timestamp: July 29, 2017, 08:45:32 am
content: I meant Art of Electronics.A friend asked about what that was supposed to be and it seemed familiar to me. Still do not remember from where thou.It's from an interview question: what is the function of the 100-Ohm resistor?

author: Zero999
author_rank: Super Contributor
timestamp: July 29, 2017, 09:38:52 am
content: Quote from: lilmantis on July 29, 2017, 08:45:32 amThe resistor will absorb the high voltage spike created by the inductance, when the MOSFET is turned off.

author: lilmantis
author_rank: Contributor
timestamp: July 29, 2017, 10:01:03 am
content: That was my initial assumption too.Any idea on what this actually is?

author: RoGeorge
author_rank: Super Contributor
timestamp: July 29, 2017, 10:28:02 am
content: I guess it's one of those kinds of open questions, to evaluate the applicant on a broader range.For that particular case, I guess it will be a good point to also mention that the wires made a transmission line, so the resistor will help minimizing the reflections, so minimize the oscillations, so it might lower the parasitic EMI radiated by the wires. Maybe they were expecting to compare it with just a diode instead of the resistor, and so on, a discussion.

author: lilmantis
author_rank: Contributor
timestamp: July 29, 2017, 10:44:19 am
content: Thank you guys for your answers.Still can't remember where I saw this, guess I'll try harder or get over it.

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 29, 2017, 10:59:52 am
content: Quote from: danadak on July 28, 2017, 10:05:32 pmThe Art of Electronics Book... the abbv is not available in wikipedia yet as this is specialty to eevblog community, get used to it...(refer back to the earliest eevblog video for book suggestion) ps: maybe we can suggest to Dave to call it "home" so the owners are "homies" and who doesnt own it we call them homeless.

author: Zero999
author_rank: Super Contributor
timestamp: July 29, 2017, 12:08:50 pm
content: Quote from: RoGeorge on July 29, 2017, 10:28:02 amYes, it can be treated as a transmission line, if the MOSFET switches fast enough. Then the MOSFET turns on, then the transmission line is still not matched: at one end there's only 0.1R and at the other the RONof the MOSFET. When the MOSFET turns off then, assuming the transmission line has an impedance of 100R, then it will be matched by the termination resistor.