How do you alter the magnitude of an AC Voltage?

[aidanfusco]

Hello,

I was recently asked the following question at interview for an electricians position, 'How do you alter the magnitudle of an ac voltage?'. Could anyone help me regards an answer for this for future reference? I didnt end up getting the position, but it has bugged me ever since. I have spent a bit of time reading through ac theory and vector diagrams etc and cant seem to get an answer.

Thanks in advance
Aidan

 

[3v0]

I would think by magnitude they are referring to voltage itself. I would have said to use a stepup or stepdown transformer.

 

[aidanfusco]

Hello 3vo, thanks for taking the time to reply. I think your thinking is correct, I couldnt figure what they meant in a practical sense. Although during the interview when the question was asked, I was given a nudge in the direction of vectors, hence why I looked at ac theory online.

 

[3v0]

My answer was rather "off the cuff". Lets see what others have to say.

And While I am here. Welcome to ETO.

 

[colin55]

This is a very complex question and there are many answers.
I am working on a mechanical TV project and to increase the AC voltage (waveform) from a sensor I have 3 options: make the disk spin faster, use a stronger magnet and/or place the magnet closer to the inductor.
Then there was another requirement to increase the AC waveform from an oscillator. The answer was to increase the DC supply.
This is just 2 of a thousand answers. It's a bit like saying "Where do you find a 1k resistor in a circuit?" How complex do they want to answer to be?
That's the problem with going for a job.
I generally get my students to take a microcontroller project with them and show it. Luckily every student won a position with this tactic. It's just something that changes the status from being asked a lot of unnecessary questions to talking about something where you are in control, and shows your ability at electronics.

 

[porten]

There are several ways you could do this and one of them being the use of an amplifier. Colin55 has a good point and I've been a big fan of loading your resume with many projects you have worked on. Most of my classes had a project that I could list on my resume that gave me a lot to talk about in an interview. It almost always seemed as if they were more interested in my past experiences/projects than asking me random questions.

 

[colin55]

always seemed as if they were more interested in my past experiences/projects than asking me random questions.

That's exactly right. By taking a project with you, you become in-charge of the discussion and it "takes a load off" the interviewer and he feels you are very easy to interview. It's one of the secrets that no-one ever mentions.

 

[cr0sh]

The OP said he was going for an electrician's position; not an EE position, or anything else where showing off electronics prowess was needed. I'm willing to bet the answer was "use a transformer rated for the input voltage and current needs"; unless the OP is using the term "electrician" to mean something else...

I do agree, though, that if you are going in for an interview, and the competition is tight (or you think it will be), having a portfolio and/or physical project with you will make you stand it; you are there in the interview to sell your skills and your knowledge to the employer - they'll remember the competent guy with the project.

 

[porten]

Oops I missed that part about going for a position as an electrician. In that case using a transformer is most likely the way to go.