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Trying to generate 1khz sine wave at 2A

Posted by Moriquendi 
Trying to generate 1khz sine wave at 2A
November 04, 2016 11:29AM
Hi all,

This isn't directly reprap related but I know there are some smart people on here so I thought I'd ask anyway.

I'm trying to put together a power supply for a project I'm working on involving linear variable transformers and other magnetic coils. In order to excite the coils I need an AC power supply capable of about 12-18v and 1.5-2.5A at between say 100Hz and 1KHz. I'm having great difficulty finding something suitable that fits my budget.

So far I've tried using the output of a microstepping stepper driver but there have been a couple of issues, I can't reach above 250Hz and the output is very noisy.

My next idea is to use a sine wave generator followed by an integrated audio amp chip. I don't have these parts on hand so I thought I'd ask for any other ideas before I go and get them. Any thoughts?

Many thanks,

Moriquendi
Re: Trying to generate 1khz sine wave at 2A
November 04, 2016 04:01PM
It sounds like you need a 50W audio amplifier. Look for class D (or T) switching amp chips- usually extremely efficient and very compact (high efficiency means less heat sink).


Son of MegaMax 3D printer: [www.instructables.com]
Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]
Re: Trying to generate 1khz sine wave at 2A
November 04, 2016 04:20PM
Audacity can likely produce the 1khz sine wave for you, too.
Re: Trying to generate 1khz sine wave at 2A
November 05, 2016 04:11AM
[www.rme-audio.de]
[www.mediacollege.com]
[www.youtube.com]

maybe not what you want, confused by the 2A part, if someone can explain.

Edited 1 time(s). Last edit at 11/05/2016 05:01AM by MechaBits.
Re: Trying to generate 1khz sine wave at 2A
November 05, 2016 06:20AM
I'd thought of using a class D amp but I wasn't sure whether the switching noise would be an issue. Of course they're designed to drive an inductive coil which is exactly what I need to do and by the looks of it the switching frequency is in the MHz range so hopefully it wont be a problem. I've ordered a 100w (claimed) module.

I hadn't thought of using my computer to generate the signal, it'll be very useful for experimenting but I'll need to make something more portable in the end.

2A refers the the current output, I need to drive significant power into the coil, hence 12-18v at 1.5-2.5amps which will be 18-45watts, not something you can get from a soundcard.

Thanks for the help

Moriquendi
Re: Trying to generate 1khz sine wave at 2A
November 05, 2016 07:06AM
See [www.sdiy.org] for several ways to generate sine waves. The Wien-bridge oscillator using a light bulb (see page 3) was how HP got started making test instruments.

If you don't need especially low distorion, you could makes a sine wave source using a uC and DAC.

Edited 1 time(s). Last edit at 11/05/2016 07:07AM by the_digital_dentist.


Son of MegaMax 3D printer: [www.instructables.com]
Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]
Re: Trying to generate 1khz sine wave at 2A
November 07, 2016 12:38PM
This might be of interest:

[www.tinaja.com]

Discussion:

[electronics.stackexchange.com]

Edited 1 time(s). Last edit at 11/07/2016 12:39PM by Zedsquared.
Re: Trying to generate 1khz sine wave at 2A
November 09, 2016 05:42AM
Good find, thanks. Most of the maths is over my head but I'll try and make sense of it.

Moriquendi
Re: Trying to generate 1khz sine wave at 2A
November 10, 2016 11:57AM
If you have an amp, just put a sine.wav on a portable audio player. Is that not portable enough?
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