Hi,
I have just started the process of renovating a Lenco L78 turntable. Plinth, bearing, idler wheel, tonearm, etc. I have spotted the SG4 motor controller, which I understand works very well with Lenco AC motors. Can please someone tell me whether that controller is available as a complete component, so that I do not have to gather the parts and build it myself? (I live in Athens, Greece).
Thank you!
I have just started the process of renovating a Lenco L78 turntable. Plinth, bearing, idler wheel, tonearm, etc. I have spotted the SG4 motor controller, which I understand works very well with Lenco AC motors. Can please someone tell me whether that controller is available as a complete component, so that I do not have to gather the parts and build it myself? (I live in Athens, Greece).
Thank you!
@SRMcGee, thanks a lot for the response and the encouragement for trying to build it myself. I am afraid that I have neither the necessary knowledge nor the tools to proceed with the build. I'd prefer to follow the OP's (@Pyramid) advice "Do not attempt this part of the project if you are not trained in handling power electronics: Seek competent technical help if needed."
So, I apologize in case I am going against the forum's rules about DIY, but I am wondering whether someone competent enough can build the controller for me. If my request is unacceptable for posting it here, I kindly ask the administrator / moderator to delete it. Thank you.
So, I apologize in case I am going against the forum's rules about DIY, but I am wondering whether someone competent enough can build the controller for me. If my request is unacceptable for posting it here, I kindly ask the administrator / moderator to delete it. Thank you.
Last edited:
I'm certainly no expert, but are you saying that the -P003 variant (https://www.mouser.com/ProductDetai...VN0106N3-G-P003?qs=Q7eD95YXrua%2Bjseq8E4gMA==) won't work?
Regards.
The version specified in the project listing on Mouser is out of stock and shows that it won't be in stock until Feb. 6 2024.
I'm not certain. That's why I'm asking.
Now out of stock, hopefully available by the end of Feb, early March.
These chips are starting to become a problem to source.
There are a few people who have requested these, I'll post here when I have some stock.
Got a weird issue. Built this 2+ years ago now and it has worked without fault since, except… the last month or so. Now after running for an hour or two or sitting in standby for a couple hours it slows down significantly. Also have digital tach hooked up and it will slow by 2 to 3 tenths of an rpm, whereas previously it never deviated by greater than +/- 0.02 rpm. Any ideas? Bad capacitor??
I have a old Rega Motor Premotec 9904series in a highly modified turntable. Its set for 220AC config with the 6,8Kohm series resistor for the 110V motor. When applying a sg4 controller I see no use of this and get rid of the series resistor (and cap for 90deg)to get it run directly at 110V. Is this correct? When applying step up transformer I can use a 110+110v primary to 12+12v secondary 30VA trannie together with suitable amplifier like this link
Do I need 2 transformers for this or is the double secondarys fine, How do I apply this? Any suggestion for transformer?
Do I need 2 transformers for this or is the double secondarys fine, How do I apply this? Any suggestion for transformer?
Last edited:
I'd recommend the amp in the following link or similar. I know it works and am not sure about the one you mentioned.
https://www.amazon.com/gp/product/B082QR5WVL/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
You can eliminate the resistor and capacitor in your diagram. You'll need 2 110/12 v transformers - one for each phase. 0 degree phase goes to one channel and 90 degree goes to other channel on the amp. output from one amp channel goes to both secondaries of transformer (in parallel). Same for the other channel. Then connect secondaries in parallel to red and grey. Secondaries of other channel go in parallel to blue and grey. I'm doing this from memory, but I think the 0 phase goes to red wire.
I think 10VA is adequate for transformers but I'd use 25VA to be sure. These transformers don't need to be anything special.
https://www.amazon.com/gp/product/B082QR5WVL/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
You can eliminate the resistor and capacitor in your diagram. You'll need 2 110/12 v transformers - one for each phase. 0 degree phase goes to one channel and 90 degree goes to other channel on the amp. output from one amp channel goes to both secondaries of transformer (in parallel). Same for the other channel. Then connect secondaries in parallel to red and grey. Secondaries of other channel go in parallel to blue and grey. I'm doing this from memory, but I think the 0 phase goes to red wire.
I think 10VA is adequate for transformers but I'd use 25VA to be sure. These transformers don't need to be anything special.
Here's a better link for the amp.
https://www.amazon.com/dp/B01CZQAFCO?psc=1&smid=A30QSGOJR8LMXA&ref_=chk_typ_imgToDp
https://www.amazon.com/dp/B01CZQAFCO?psc=1&smid=A30QSGOJR8LMXA&ref_=chk_typ_imgToDp