[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] Treadmill Motor Question



Jim,

Does the waveform from an SCR controller make this type of DC control a bad
choice or is it an issue that may not be that noticeable to us average
experimenters? I have a DC motor with an SCR I was planning on using for a
ASRG.

Thank you.

Tim


On Tue, Sep 10, 2013 at 9:31 AM, Jim Lux <jimlux@xxxxxxxxxxxxx> wrote:

> On 9/10/13 5:30 AM, Yurtle Turtle wrote:
>
>> Question for the list experts. If one were to employ a DC rsg motor
>> with full wave rectification, are filter caps needed? Is the ripple
>> any worse than pulsed AC from an inverter or pulsed DC from a cheap
>> SCR speed controller?
>>
>>
> You're talking about a brush DC motor, right?
>
> Basically, you're relying on the inductance and mechanical inertia for
> "filtering".
>
> The only thing I've noticed when doing this kind of thing is that the
> harmonic content is higher, so there's a bit more heating of the windings
> and/or noise (hum from the vibrations).
>
> This is more of an issue with the SCR controller (waveform with lots of
> sharp edges) than, say, variac and a bridge.
>
>
>
>>
>> ______________________________**__ From: David Rieben
>> <drieben@xxxxxxx> To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
>> Sent: Monday, September 9, 2013 7:45 PM Subject: Re: [TCML] Treadmill
>> Motor Question
>>
>>
>> Adam,
>>
>> Yes, that's what I am doing with my current ARSG in my big Green
>> Monster coil. It's a sweet treadmill motor that I got off eBay
>> several years ago that was easy to mount and to mount a G-10 rotor to
>> and it required no external fan blades to keep it cool. I'm using a
>> small variac and a FWB rectifier (and a 3900 uFd, 400 VDC rated
>> 'lytic for some filtering) to run the mo- tor. I ended up getting a
>> local machine shop to drill the holes in the G-10 rotor for me.
>> That's what I would do with any future RSG mounting project as well.
>> There's just no way that I could get it smoothly balanced and get all
>> of the holes drilled true with my facilities.
>>
>>  <
> <long snip of previous emails>
>
> ______________________________**_________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/**listinfo/tesla<http://www.pupman.com/mailman/listinfo/tesla>
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla