Dear All,

I am in the position of having to supply a technical test to our HR dept and for some forthcoming for an electronics engieering position.

I havhad to take several of these before when attending interviews myself but basically I dont know how high to pitch it or what it can prove!

I was interviewed as asking me to talk them through a schematic which is much more akin to the practical work involved.

I have looked at some sample "electronics" tests that around on the internet and I can't do them all without reaching for my Uni textbooks!

The actual role is a very broad role which encompasses embedded programming and electronics and could equally be done by a software engineer with some basic electronics knowledge or an electronics engineer with a strong embedded software background.
I dont want to miss potentially good people because they cannot recall the small signal equivalent circuit of a BJT off the top of their head! However I would expect them to bias one correctly as a low sided switch.

any ideas?

I am slightly worried by the "having to supply a technical test to our HR dept", does this mean an engineer will not be supervising this test? If this is the case it will be very difficult, as different engineers tend to have very specific skills in circuit design (depending upon their particular experience). It is very likely that two engineers with similar aptitudes could score very differently depending upon, almost, pure luck. You would probably find in this case that the test would be kept very basic to cover common knowledge, which may well be too basic for what you require.

However, if the test is supervised by an engineer it becomes much more straightforward. For electronics design my first stage is typically to ask the candidate to talk through one of our circuits in the following process:

Show them the circuit with just the question "how does this work?"

If they are unable to get anywhere at that level, I will explain the function of the circuit and then ask what the circuit blocks do

If they are still stuck I will focus in on a particular element - a transistor switch is a good example - and start from there

The point of this test is to confirm that the candidate really does understand the "language" of electronics, and can find their way around unfamiliar circuits. It is a useful gateway.

The second stage is to do more of a "what if": "how would you design a circuit to carry out an xyz function?" Again this can be drilled down in many ways:

Would you use a digital or analogue circuit here? Why?

Would you design a board for this part or use an off-the-shelf embedded PC? Why?

To be honest, you can go into as much detail as you want here. Do make it clear that it is just an exercise though, I have had candidates thinking that we were trying to get free design advice from them! To help with this I usually use one of our existing products for this exercise, so that after this stage I can show them how we approached the problem (which can also open up useful areas of discussion.)

The point of this test is to see how they approach a design problem, it does not matter if they come up with a totally different solution, you want to see that they have taken a methodical approach, have a good understanding of what technical solutions are available, and understand wider needs such as cost, safety, EMC etc.

With both tests I have gone on to recruit candidates who in interview have said "I have no idea what that part of the circuit is" or "to implement this it would be best to use an 'xxx' function but I would not know how to design it". It is often just as important that candidates know the limits of their knowledge! I had a successful interview once where I was asked "how would you design a state variable filter?" Never having designed one before I gave the honest answer "I would look in the Active Filter Cookbook". It did not actually matter that I did not have the full experience - at least I had enough experience to know where to find the answer. This is where you really need to give the interview, because often only you can judge the trade-offs between the candidate's knowledge in one area against their lack of knowledge in another.

Hope this helps,

Andy

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Andy Millar CEng MIET MCMI

http://www.linkedin.com/in/millarandy

Edited: 10 June 2010 at 04:05 PM by amillar