Turntable power supply - capacitors?

The capacitor doesn’t half the voltage, there will be a resistor that does that.

There are two windings in motor, the 22uf capacitor generates 2 voltages approximately 90 degrees out of phase. (if they weren’t out of phase the motor wouldn’t turn).

I haven’t seen the Ariston arrangement, but if the capacitors are close to the resistor there’s a good chance they’ve been subjected to a fair amount of heat.

If they’re film caps and haven’t been subjected to heat, they’ll probably be OK.

This is a very similar arrangement to early linn lp12s and works well enough

If you want to further improve smoothness then it might be worth reading up on adjusting capacitor values to get the smoothest running motor possible...also dropping the voltage further may benefit smoothness

Sorry if these suggestions contraven forum rules ..pls delete if so 

Speaking from a position of (almost) complete ignorance here, one thing jumps out at me: if you have a motor which is “an AC synchronous 110 V unit”, even if you have a capacitive voltage divider (certainly possible, just as easy for AC as a resistive voltage divider) to shift you from your 220 V supply to the 110 V operating voltage, won’t you have a more fundamental issue with line frequency? I’m guessing the 110 V motor wants to work off 60 Hz, the North American standard, any you want to power it from 220 V 50 Hz, the UK (or Euro) standard. Sorry if I’m missing something obvious here and you’ve already had this working properly... but it was a flag for me to read “AC synchronous” more than your actual question about the voltage conversion or the shelf life of capacitors... since the motor speed is the thing which is “synchronous” with the line frequency. Worth thinking about, if you haven’t already, and apologies if this is irrelevant (however well intentioned!).

Regards alan

The motor is designed to work with 220v @ 50hz for the UK market.  The US market version does not have the voltage halving circuit because the supply is at 110v.  The pulley diameters are different I believe though to account for the different frequency.

The unit has worked for the past 35 years off uk mains, but it’s speed and stability is entirely dependent on the mains frequency.

The Heed unit is designed to provide an accurate and stable 220v at 50hz for 33.3rpm, and (I think) 67.5hz for 45rpm.

Note that as far as I am aware it is a capacitor voltage divider - there are lots of references online, even a calculator - I found this diagram (I do intend to open it and have a look later though).  This is the origin of my question, because with the Orbit 2 this circuit would still be needed to work, and I don’t know what affect the age of these components has.

 Will it run directly off the mains directly OK? 

Vinyl engine has a manual you can download but maybe you’ve found that. 

I’ve had occasions, admittedly with the resistor type voltage dropper, when  a new phase capacitor has been fitted that the pulley doesn’t turn but just quivers. If you give the platter a spin in the right direction it will keep going. Once I’ve done this a few times it will start normally when switched on. I think the capacitor was reforming itself with a bit of use but that bit is a guess.

Do you have a photo of the components.

The .22uf capacitor is the value required to produce  an approx phase shift of 90 degrees on a 50hz supply.

It does run off the mains fine, but it’s speed and stability will be directly governed by the quality of the mains frequency.  This is presumably why LP12 owners spend ever increasing sums on power supplies, but I think Linn now use a 24v motor.  However the purpose of this is to overcome mains frequency variability, which the Heed provides, as do other similar supplies.  

That is exactly the capacitor value in the manual.  I’ll see if I can post a photo later.

If it runs off the mains it will run off the heed I should think. Just use it a while.

This is what the manual shows:

This is what is inside (I have rotated it so it the same orientation as the above diagram.  It is  different; the capacitor value is different, I think the rectangular component (RS 156 052 10k 5%) is a 10K resistor (?), and there are only three wires for the motor that are not in the same order!  The Manual is pants basically, except for the switch and suppression capacitor everything is different.

This is the reverse side (horizontal flip of above image - mains enters on left):

Marvellous.

Just to complete this, here is the motor:

I have no experience of the Heed Orbit . I would recommend taking a look at the Origin Live DC Motor kits . It was a serious upgrade for my Systemdek away from the stock synchronous AC motor .

Just play the bloody thing and quit worrying unless it goes pop, which as it runs on the mains OK it won’t.

yeti42 posted:

Just play the bloody thing and quit worrying unless it goes pop, which as it runs on the mains OK it won’t.

???? Yep, that’s exactly what I find myself thinking too! 

SB posted:

I have no experience of the Heed Orbit . I would recommend taking a look at the Origin Live DC Motor kits . It was a serious upgrade for my Systemdek away from the stock synchronous AC motor .

And I would recommend staying as far away from origin live kits as possible !!

But we are all different!!

Judge posted:

It does run off the mains fine, but it’s speed and stability will be directly governed by the quality of the mains frequency.  This is presumably why LP12 owners spend ever increasing sums on power supplies, but I think Linn now use a 24v motor.  However the purpose of this is to overcome mains frequency variability, which the Heed provides, as do other similar supplies.  

That is exactly the capacitor value in the manual.  I’ll see if I can post a photo later.

starting torque depends upon voltage  T PROPORTIONAL V squared    speed is dependant on frequency   which shouldn't be a problem. 24v should produce enough starting assuming belt is ok.  heed psu does the job well too.

In my tests , on a similar but linn 120v motor...it needed about 60+ volts AC just to keep running so not sure how you think 24v will be enough?

audio1946 posted:

Judge posted:

It does run off the mains fine, but it’s speed and stability will be directly governed by the quality of the mains frequency.  This is presumably why LP12 owners spend ever increasing sums on din rail power supplies, but I think Linn now use a 24v motor.  However the purpose of this is to overcome mains frequency variability, which the Heed provides, as do other similar supplies.  

That is exactly the capacitor value in the manual.  I’ll see if I can post a photo later.

starting torque depends upon voltage  T PROPORTIONAL V squared    speed is dependant on frequency   which shouldn't be a problem. 24v should produce enough starting assuming belt is ok.  heed psu does the job well too.

low-voltage (24 volt) systems clearly should be away from enough