Sweep Generator and Breadboard Question

[Desdemona]

Hopefully this question doesn't make me seem completely clueless, but I can't seem to find a good answer.

If I wanted to add a controlled AC Power Source to a breadboard setup would a function generator be a safe way to do so? The particular model I have in the classroom is a BK Precision 4040A. I can list it's output if function generators vary alot.

Are there special factors I need to consider if it is safe? Such as making sure the Breadboard has some sort of ground before apply power?

If there is a good online source for this or even a book that deals with AC and Breadboards directly I'm good with resources.

Thanks!

 

[davenn]

hi there ... welcome to the forums

you havent really told us how this AC controller will possibly work

DO NOT bring AC power ( I'm assuming you are referring to mains AC 120V/220V etc) onto any breadboard have low voltage leaving the board to the relay or whatever that is switching the AC

You had better tell us more specifically what you are trying to achieve

cheers
Dave

 

[Desdemona]

I don't plan on trying to plug AC directly into the breadboard. I'm trying to replace old/clunky test consols that we use with breadboards. This way the students can build the circuits. We use the class to teach them troubleshooting but the one component circuits they troubleshoot are pretty laughable, WAY to easy (these are adult students).

Anyways, I thought it would be cool for them to build a really basic power supply onto a breadboard, put in AC and see how it turns into DC. We have sweep generators in the class already which they use on the test consols on simple RC and RL circuits. Instead of using the test consol they could, maybe, build those too. But, I can't do that unless I find a safe power source. I have seen breadboards that are more complex than just copper and plastic, but I was trying to stay simple. Since we already have the sweep generators in stock reusing equipment already owned will be the best in order for me to sell the idea to those above me.

It would be preferable to let the students change the frequency of the singals that go into these circuits, which is the current use of the function generator. I'm a IT teaching this class, so my knowledge of electronics is really limited. We are not "fix the circuit board," ITs... we are the "throw it away and buy a new one," type

 

[Desdemona]

(If it's applicable). They won't be troubleshooting on these boards, with exception of their own errors, we will have prefab boards for that, which are in no way attached to the bardboards. We currently use breadboards for DC circuits with low amp power supplies. So, I'm trying to see if I can bring that into the AC side of the house, but all we do with AC is show how a basic "wall wart" power supply works.

 

[BobK]

Why not just use a transformer?

Bob

 

[Desdemona]

Transformer to step down the output from the function generator?

Just making sure I understand the suggestion correctly

 

[BlairH]

A signal or function generator would work, but they typically don't generate a significant amount of power. The source impedance of these units is usually 600 ohms, some are 50 ohms. It would be OK for low current work, e.g. to show how a half wave rectifier or a full wave rectifier circuit would work, but you most likely would not be able to power anything substantial from one. You could combine a generator and an audio amplifier, however, the performance of the amplifier at 60 Hz may be limited.

 

[KrisBlueNZ]

Just a transformer powered from the mains supply.

Look at the circuit for a typical linear supply. Mains power feeds a transformer with a secondary winding that provides, say, 15V AC RMS. That feeds to a bridge rectifier, filter capacitor(s), regulator and so on.

You just need to provide the transformer, pre-wired to a mains cable to plug into a power socket. The secondary side is all low-voltage and the students can build the rest of the power supply on breadboards.

You don't say where you're located or what your mains voltage is. There's a field for your location in your profile; it can be helpful for us to know this information.

Here's one rated at 16V AC RMS, 800 mA, with a tapped primary so you can use it at 115V or 230V. It's USD 13.35 from Digikey. You would need to mount it in a plastic enclosure. http://www.digikey.com/product-detail/en/DP-241-5-16/595-1080-ND/952950