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.
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