Yamaha Leslie unit

[Toxophilite]

I have one of those 2 speed ittle Yamaha leslie units like the ones used in the Ra-100 etc, similar to the ones David Gilmour uses.
It's a pull from an organ and it uses 100 VAC in from the organ amp. It has it's own little circuit board to switch motor speeds.
I built a footswitch and hooked it up to the connections that used to go to the organ controls and it switches speeds great
And while it does work fine plugged straight into the wall, it's about 20 more volts AC than it's supped to be getting.


I'm wondering if I should worry about it or if there is a nice safe way (giant resistor?) to knock down the AC voltage 20 volts to a level it's more used to


Thanks

[sluckey]

I would use a bucking transformer. Build this using a 24V 3A transformer and without the voltage selection switch.

[Toxophilite]

Cool!
i could handle making that
Thanks a lot!

[Toxophilite]

Just talking to the guys at the electronics store on the phone, had to tell them 'bucking' started with a 'b' to keep them on the line
Nevertheless it confused them
My understanding was that it was a regular 24VAC 3 amp power transformer used in a particular way, AS a bucking transformer rather than a specially made transformer , yes?


*&^(*&^(*#$@$#&* bucking transformer!!!

[Willabe]

     Yes. 

It's wired out of phase so it 'bucks' (cancels/subtracts) the secondary voltage on the amp/unit by what ever voltage it is.
 

[Toxophilite]

grr had to buy a 4 amp &*%$#@ bucking transformer...that never stops being funny!


It's on the larger side, would a 2 amp one work in this application, they didn't have a 3 amp
It seemed safer to go with the bigger size


I've heard that bigger is better when bucking

[sluckey]

It's on the larger side, would a 2 amp one work in this application

Probably. Can you determine how much current that motor assembly draws? I doubt it's 2 amps, but check. If you can't determine the current draw then put a 2 amp fuse in line with the motor. If the fuse holds then that 2 amp transformer should be good.

I've heard that bigger is better when bucking

It's not how big it is, it's how you use it. Guess who says that?


Answer... The guys with the small transformers!

[Toxophilite]

Thanks! good thing I installed this one already..whew!

[sluckey]

Did it bring the voltage down to where you wanted? Do the motors run OK on the lower voltage?

[Toxophilite]

I must admit I copped out on the 24 VAC one because it was as big as a small grapefruit and HEAVY!
I with the 12VAC 4amp model . It fit nicely and brings the wall voltage down to 107 which I think I can live with...hopefully the leslie can too!!
I don't know if it runs any slower but maybe it's a bit safer/ahppier
That was a cool thing to learn about!
Here is is in all it's makeshift glory
I call it the Leslie Coop ...deville
It works really well!
Now I will have one Leslie rotating on a horizontal plane(my other little one) and this one rotating on the a vertical plane
No-one will escape the doppler effect!!

[sluckey]

Hey! That resembles some small cages I built for bay squirrels. 

[Toxophilite]

Actually with the rotary feature it could very well be a squirrel cage, Before I mounted over the Yamaha's base it looked an awful lot like a cat carrier and our cat fit nicely in it

[sluckey]

Small squirrel cage...

[Toxophilite]

Looks like there might be room in there for a little leslie!

[sluckey]

Or maybe some baby squirrels in your cage!   

I know I'm sometimes weird, but you do see the similarity, right?

[Toxophilite]

I totally see it! Their almost identical!! though you could use a little flat black and gold paint on yours
That's why I called mine a coop! I just had that wire screen on hand from making my girlfriend a butterfly cage from 2, 15" speaker baffle cutouts   for her grade 2 classroom. I tend to use what I have on hand



I think your squirrel cage is a lot cuter than my leslie cage


Are you rescuing squirrels? That's pretty cool if so? Must be neat and interesting
We have mostly larger squirrels around here (imports from back east!) but the native Douglas squirrels and the chipmunks are pretty funny, very fierce,territorial and tiny!

[sluckey]

Yeah, we rescued squirrels for about 10 years. Lot of fun. Lot of work too! Once we had 9 squirrels of various sizes at the same time. Here's what the dining room looked like after a feeding session. Hey, I bet your butterfly cage maybe resembled these larger cages...

[Toxophilite]

Nice! Thats a regular squirrel community
I like them hanging like birdcages. Did they like that better or was it just easier for space?

I'm currently in the big smoke, no critters in an apartment dammit!

My butterfly cage did look a lot like that, but because I had this light screen door mesh I had some maple organ pedal uprights going around the edge of the top and bottom round, to frame it up otherwise it would've been like a concertina!
That heavier grid would be good for the leslie. I poked my drill right through the light mesh by accident when I was attaching the handle.
I like a grill or mesh because I think if you're going to have something that rotates, you should be able to see it too. I get lot's of questions at shows about my other leslie, mostly "What the heck is that thing??" Adds to the general entertainment

[sluckey]

Your speaker is actually rotating in that Leslie, right?

[Toxophilite]

Yes indeed.


I have one that's a 6x9 mounted in a rotating upright wooden drum. I think it was pulled from a Baldwin Organ


I wanted it because the speaker actually rotates and you can hear the high end . When it's a speaker blowing into a baffle it tends to cut the highs and be a little more low mid honky. (I've had a couple of those, both wooden and styrofoam)


The yamaha unit is also an actually rotating speaker but it uses a different mechanical method.
Speaker mounted on a rod with a counter weight at the other end, Center of rod rotates on a crosspiece with the usual motor, pulleys and belt arrangement

[Toxophilite]

Tried this yamaha lesie unit out last night running from the ext speaker jack of my super, playing with a loud drummer and bass player, sounded great!, If you come across a defunct Yamaha electone organ(you'd have to look up the models that had a rotating speaker) I highly recommend pulling the leslie. (if you like that sound)