Interview tips for power supply design position (new Grad) 3

[crosman]

Hi all,
As you can tell from the subject I am a recently graduated undergrad. I have an interview scheduled for next Friday with Artesyn Technologies in MA. More specifically with their power group.
It doesn't have to be specifically for this company but what kind of technical questions should I expect for a new grad for a power supply design position.


To give you an idea here is a small part from the job description
"Assist other engineers in testing, analysis and design of high density, high performance, low cost power supplies, both AC/DC and DC/DC, from 100W to 2.5kW."

"Working knowledge of electrical simulation tool such as Spice or similar. Experience with Labview for automated electrical bench testing a plus."

Any tips would be appreciated.
Thanks

 

[IRstuff]

You should be able to at least draw out the topologies of canonical switching buck, boost, buck/boost supplies, linear supplies, etc. Be able to identify pros and cons of the various technologies.

Understand and be able to explain the similarities and differences between BJTs and MOSFETs

Be familiar with the transfer characteristics of BJTs and MOSFETs

Be able to work your way through a differential pair

Be able to figure out voltage drops for combinations of diodes and EB junctions.

Note that the interviewers don't necessarily expect you get all the answers right. They DO expect you to understand HOW to get an answer.

Have an answer for where or what you want to be in 10 yrs

Dress and groom neatly; sit straight and don't slouch

If taken to lunch, don't salt your food before you taste it

Speak in a professional manner; avoid slang and IM language

Have clean and high-quality copies of your resume available



TTFN

 

[crosman]

Thank you for the detailed answer. This was just what I'm looking for.
If anyone else has anything to add as far as the technical questions go, it would be very much appreciated.

 

[itsmoked]

As an aside I am told that if you really like the "design" aspect of EE you must be careful with a position in "testing" since it can be hard getting back out of testing into design. If you like testing an would be happy there then have at it.

 

[IRstuff]

Mostly in general, I took a course in power electronics in college. I've participated in interviews from both sides of the table. College grad interviewing is generally pretty limited, since most companies pretty much assume that a new grad knows next to nothing and the only real prerequisite is that they're trainable. Clearly, anything that you can do to dispel that misconception will make you a stronger candidate.

You might want to review their company's profile:

http://www.artesyn.com/media/pdfs/co_profile.pdf

as well as other information you can glean from their website:

http://www.artesyn.com/powergroup/products.htm

This is SO much easier; it used to be very difficult to get any detailed understanding of a company's business and product line prior to interviewing.

"testing, analysis and design" is pretty much motherhood. The excerpt sounds like they'll let you try pretty much anything you're capable of doing.

TTFN

 

[itsmoked]

As IR sez the most important thing is that you are presentable and look interested and attentive. You can pass all the other things on their list but if you look like a slob or are there for "just a job" red marks will appear..

Do indeed check their website and see if you can come up with a few clear questions that, actually interest you, in the area they all looking to fill.

 

[crosman]

This is an interview from which I would really want to get a job offer.
I know that there are many important things to be careful about at an interview. But technical questions seems to be the most important of all. At the end of the day, they really need to know if you are capable of "engineering"
So I really want to cover if not all but most of the possible questions that could be asked.
If anyone can think of any other questions it would be great
Thanks

 

[hrc]

Be honest with your answers. They can see thru the lies if you don't have the experiance. From what I've seen with new grads, they don't teach power electronics anymore. Its all software and digital. I imagine they are looking for an entry level type who has the ability to pick up on things and be mentored.

As an aside, I've worked with the engineering team there, and know a manager or two. Top notch company. I currently use thier parts in several of my designs.

 

[OutToLunch]

You may also want to do a little research on some industry specific type of regulators such as the multiphase buck - these are used in a lot of modules, Artesyn probably makes some. Perhaps a basic knowlege of hysteretic regulation would be good. These kind of things might just be asked to see what you may or may not be familiar with.

Be very familiar with the basics of inductors. V=L*di/dt goes a long way.

What considerations are made in the selection of capacitors used on the output of a switchmode regulator?
What considerations are made in the selection of capacitors used on the input of a switchmode regulator?
What is the ESR of a capacitor?

If your analyzing the stability of a switchmode regulator, what would the IDEAL gain plot look like on a bode diagram?

Can you calculate the switching losses in a FET?
How about a diode?

In terms of testing...
- How would you measure the gate-source voltage of a high side FET in an H-Bridge or even just a buck regulator?
- How would you measure the current through the FETs?
- Do you know how to use a spectrum analyzer?

that's all i got...

 

[advidana]

I was a techie for my first 8 years in engineering, but 100 percent design at much higher voltages is where the steady money and advancements are.

If you want to be in the testing, analysis and design in electronics then tell your employer why. He really doesn't expect you to know much other than you are book smart at this point in your profession. Tell him that you would like to be an on hands person to do design, analysis and also work with test equipment. Most of all tell him or her you want to learn from him or her all you can about the design analysis and testing business and mean it.

Be sure you review all you can about inexpensive power supplies ,low power types, in the range they are looking for.

The job looks like it will be in a lab with you working with a small amount of people, so all you need to do is click with this group.

It's a tuff business. These types of job will last about a year if you are luckly even if the boss tell you it is for ten years. Remember electronics is very go-go and big bucks for shorts periods at working for many companies in big cities. So alway be ready to be looking for another job and always keep up with the technology. Be nice to all your co-worker because you will be running into the same people in different companies.

good luck.

 

[crosman]

Thanks to everyone who has replied to my post.
I received the job offer!
Thanks

 

[itsmoked]

Outstanding!

 

[crosman]