Two phase controllers in series?

Well there may be a problem if you already have a electronic speed control in side it. If all it has is a rheostat type speed control then you're all set.

Jamie wrote in news:HnSmj.126$ snipped-for-privacy@newsfe05.lga:

It does, that's why I asked about two phase controllers. :) But if it is set to pass through whatever it sees coming in, would it work as I described it? This is not something for the usual try-it-and-see approach, not on new equipmemt with maker's guarantee intact, which is also why I don't want to go in and bypass stuff.

if it has a rheostat speed control,. you can run a phase control into it as is.

Jamie wrote in news:WBSmj.128$ snipped-for-privacy@newsfe05.lga:

Anyone else? That's twice now I mentioned PHASE CONTROLLERS. Two of them. I'll take any help I can get but I'd prefer it camne from someone who reads what I say first, it saves me having to say loads more stuff that won't get read.

Lostgallifreyan wrote in news:Xns9A31F1F52E16Ezoodlewurdle@140.99.99.130:

Anyone? Can't beleive no-one here knows. Bet someone's actually tried it, too. :)

No, possibly, and no. I'm not ignoring you, I actually don't know.

FWIW I don't know either. But I will hazard a guess:-

If the internal controller is dead short then an external one would function in a similar manner to the internal one.

If the internal controller is OC, then there is no point in using an external one.

If the internal controller functions at all then all bets are off.

HTH

Most of us are probably in the range *between* far to dumb and far too clever so *wont* try stuff like that unless someone else is payiing the bill :-) I cant imagine that enything good can happen when the upstream controller is set for narrow phase angle, low power output and the control circuit down stream is getting insufficient voltage and extreme dV/dt thrown at it. Best case, its going to drop out somewhere between half speed and minimum speed, and may require a power cycle to restart or worst case you let the magic smoke out of one or both controllers. Apart from being employed by the manufacturer of a commercial external speed control, doing compatibility testing, I cant imagine getting paid to find out . . . If you do experiment with this, PLEASE video it, its gotta be better than unboxing!

Personally I'd be fitting a switch to the tool to bypass the internal controller as my educated guess is thats less hassle than fixing the possible burn-up.

Baron wrote in news:fnq4df$p0n$ snipped-for-privacy@aioe.org:

Nice. Got answers. :) Thanks. I think the same, but also that if the devices are usually made to switch off at zero crossings and on at whatever point in the cycle is determined by the controller of the triac I assume is usually used as a switch, then some waveform with enough energy even at low outputs will be useable if the second phase controller is efficient at using a supply, but it almost certainly wasn't designed to take such input...

So long as the first controller is outputting most if not all of the sine wave half cycles the second will work fine, but in my case I want to know if the other way round is ok. My guess is it might, assuming that some capacitance exists for storing the switch control supply and can store enough even with low duty cycles from the input. The other issue that I'm really uncertain about is if there might be unusually strong voltage or current surges that might damage the second phase controller.

Ian Malcolm wrote in news:fnq506$eo3$ snipped-for-privacy@inews.gazeta.pl:

Which makes me feel less like a freak cos I wasn't about to try either. :)

Yes, I think the sharp transients are the Bad Thing waiting to happen. The idea that enough power gets through to allow the second control system to work was bearable, but I can't convince myself that those transients will treat the second controller (in the drill) the way it deserves to be treated.

Couldn't do it even if I wanted to, sadly. No video camera...

Agreed. Some drills actually have a switched setting at the far end of the pot's turn, to bypass the controller, or provide another switch. This doesn't, but I think I can manage to fix this without doing anything noticeable enough to void a guarantee.