Roughly ten years ago there was another motor controller project here on DIY Audio that went off the rails because of the pulley group buy. They had the pulleys anodized and the resulting significant balance problems caused an entire batch to be rejected.
Pulleys are not easy. My hat is off to you for getting it right.
Pulleys are not easy. My hat is off to you for getting it right.
Newbie questions
I'm halfway through with my SG4 kit (boards arrived 2 days ago, parts are mostly complete) but I'm kind of stuck.
Bascially, I want this to drive my Marantz TT15S1 turntable AC motor (230V) . The turntable is essentially a Clearaudio turntable.
If I interpret all the posts correctly, I'd also need a LP12-1900 step-up transformer along with the TDA7492 power amp as outlined in the other thread for the matching power amp. That output signal (230V) would be where I plug in my turntable AC chord, correct?
I'm halfway through with my SG4 kit (boards arrived 2 days ago, parts are mostly complete) but I'm kind of stuck.
Bascially, I want this to drive my Marantz TT15S1 turntable AC motor (230V) . The turntable is essentially a Clearaudio turntable.
If I interpret all the posts correctly, I'd also need a LP12-1900 step-up transformer along with the TDA7492 power amp as outlined in the other thread for the matching power amp. That output signal (230V) would be where I plug in my turntable AC chord, correct?
Yes, you could also use an Amgis toroid PN L01-6362 which I think will work better.
The low voltage secondaries are wired in parallel to the output of the TDA7492 (or each channel can drive one secondary wired separately, ensuring the polarity mark is the same going to each output on the amp). The HV primary will be wired in series to give 230VAC that powers the table..
The low voltage secondaries are wired in parallel to the output of the TDA7492 (or each channel can drive one secondary wired separately, ensuring the polarity mark is the same going to each output on the amp). The HV primary will be wired in series to give 230VAC that powers the table..
Check that the reset controller is working. The output of U4 (reset) goes to pin 10 of U1 (uP). It should go high briefly at power up then remain low.
If you have a scope or freq counter, check that the crystal is operating at ~18.432 MHz.
Remove the uP from the socket and check that none of the contacts on the socket are bent inward or sideways. Check that all the pins on the uP are straight and uniform. Make sure the uP is seated fully in the socket when you re-insert it.
If you have a scope or freq counter, check that the crystal is operating at ~18.432 MHz.
Remove the uP from the socket and check that none of the contacts on the socket are bent inward or sideways. Check that all the pins on the uP are straight and uniform. Make sure the uP is seated fully in the socket when you re-insert it.
HELP ME WITH MY PULLEY MEASUREMENTS PLEASE.
I have a 60Hz Ariston RD11 for which I am getting a Hercules board. I do not want to change the crystals on the board and therefore want to machine my own 50Hz brass pulley since it has been next to impossible to find one anywhere.
My belt is 2 mm SQUARE. I want a V groove pulley since the belt nicely fits into it and there is minimal chance of belt slipping off the pulley. I intend to make the inside of the V greater than 90 degrees so the belt is not piched or squeezed. Am I therefore correct to assume that the INSIDE diameter (bottom of the groove) is the effective diameter since that is the closest to the pulley that moves and starts the motion ?
So, therefore the INSIDE diameter of the 50Hz pulley should be:
d = 33.3 x subplatter diameter / 250 rpm (at 50Hz)
From the above, d = 33.3 x 164.44 / 250 = 21.9 mm
I presume this is the INSIDE diameter of the pulley. The outside diameter is irrelevant since the belt contacts the pulley at the bottom of the V and that is what should be the effective diameter.
Is my logic correct ?
Comments please ?
Thanks
I have a 60Hz Ariston RD11 for which I am getting a Hercules board. I do not want to change the crystals on the board and therefore want to machine my own 50Hz brass pulley since it has been next to impossible to find one anywhere.
My belt is 2 mm SQUARE. I want a V groove pulley since the belt nicely fits into it and there is minimal chance of belt slipping off the pulley. I intend to make the inside of the V greater than 90 degrees so the belt is not piched or squeezed. Am I therefore correct to assume that the INSIDE diameter (bottom of the groove) is the effective diameter since that is the closest to the pulley that moves and starts the motion ?
So, therefore the INSIDE diameter of the 50Hz pulley should be:
d = 33.3 x subplatter diameter / 250 rpm (at 50Hz)
From the above, d = 33.3 x 164.44 / 250 = 21.9 mm
I presume this is the INSIDE diameter of the pulley. The outside diameter is irrelevant since the belt contacts the pulley at the bottom of the V and that is what should be the effective diameter.
Is my logic correct ?
Comments please ?
Thanks
Hi Pyramid,
What I would like to know is how to implement this supply of yours on a Thorens TD160.
Has anyone already applied it on a TD160? If so, please tell me the pages where the implementation was done, and what were the results. Particularly if there are things that have to be corrected or changed for the TD160 motor.
If no one knows it, the motor is a 16v AC type. Originally it came just with a filter and the corresponding transformer for 110v or 220v. My TD160 is 110v 60 Hz.
Thanks!
What I would like to know is how to implement this supply of yours on a Thorens TD160.
Has anyone already applied it on a TD160? If so, please tell me the pages where the implementation was done, and what were the results. Particularly if there are things that have to be corrected or changed for the TD160 motor.
If no one knows it, the motor is a 16v AC type. Originally it came just with a filter and the corresponding transformer for 110v or 220v. My TD160 is 110v 60 Hz.
Thanks!
Hello guys
I have a question, one member built the two boards for me, great work on his part,
What I need to know now is this. He set it up to run off what this post stated for the speeds and frequency setups
Here’s the info I need now before I make my platter , I need to know what’s the size of the pulley, and what is the size for the platter pulley and the motor ?
Can I used a old pulley off of a old turntable and make the same size that’s under the platter for the belt ?
I have a question, one member built the two boards for me, great work on his part,
What I need to know now is this. He set it up to run off what this post stated for the speeds and frequency setups
Here’s the info I need now before I make my platter , I need to know what’s the size of the pulley, and what is the size for the platter pulley and the motor ?
Can I used a old pulley off of a old turntable and make the same size that’s under the platter for the belt ?
Hi Carl Thess,
I have the same issue. I have a power supply which can generate EITHER 50 or 60 hz based on a dip switch position (Apollo Frequency Converter - KCC Scientific). It is extremely stable & good but it is the MECHANICAL pulley issues that give the problems. Unfortunately I havent come across PROPER ENGINEERING specs of the pulleys in question to build them accurately.
Even tho I measured them with calipers, I am not 100% sure of my own accuracy.
I have the same issue. I have a power supply which can generate EITHER 50 or 60 hz based on a dip switch position (Apollo Frequency Converter - KCC Scientific). It is extremely stable & good but it is the MECHANICAL pulley issues that give the problems. Unfortunately I havent come across PROPER ENGINEERING specs of the pulleys in question to build them accurately.
Even tho I measured them with calipers, I am not 100% sure of my own accuracy.
No success
Swapped the reset controller for the MCP101 and everything went downhill. Display shows only weird characters, the reset controller gets extremely hot and I can only measure 1.6V at U3 and 5.5V respectively on U2. I also replaced the 8V regulator with no success. Any idea what the problem could be? Not sure I can de-solder anything again without damaging the board.
Swapped the reset controller for the MCP101 and everything went downhill. Display shows only weird characters, the reset controller gets extremely hot and I can only measure 1.6V at U3 and 5.5V respectively on U2. I also replaced the 8V regulator with no success. Any idea what the problem could be? Not sure I can de-solder anything again without damaging the board.
The MCP101 has a different pinout than the other part and in fact has two different pinouts that are both different.
I apparently have the H bondout so I simply mounted the resent controller in opposite direction. However, when I apply power, the LED display quickly comes on and then off. Voltages are now correct. Are there other components that might have been damaged?
I've swapped this only once (suspecting this reset device could be responsible for a weird operational fault) to the MCP101 and it works properly (but still with that weird fault which I'm tolerating it for a while now till I tackle it later on). I hope you didn't damage anything else onboard during the desoldering and replacement process.
I can’t find the fault. Would anyone be willing to take a look at my board and help me fix it? In exchange I have a free spare SG4 PCB and some parts for a second build. Please PM me.
If the motor is 16VAC, you could use an amp built with the TDA7492 powered by 24VDC. The outputs are bridge mode, so you would need 22.6VPP at the outputs for 16VAC. Use once channel for the in-phase winding of the motor and the other channel for the +90° channel.
https://www.diyaudio.com/forums/analogue-source/300371-60-wpc-amplifier-diy-turntable-motor-drive-5.html#post4967916
RPM(Platter)/RPM(Motor)=(Pulley diam +d)/(platter diam +d) where d=1/2 belt diameter.
Rearranged:
Pulley dia=(Platter RPM*(Platter diam+d)/Motor RPM)-d
Try replacing U4 with a capacitor 0.22uFd to 1uFd. Install the cap in the two holes that are not ground. This will provide a reset pulse at power up, but does not provide brown out protection or may not work if the power is interrupted for a short period.
Make sure all of the contacts on the uP socket are straight and not bent inward. Make sure the pins on the uP chip are all straight and not bent in.
If you have a scope, check that the xtal is oscillating. Try another uP in case something happened to it.