I am new to this forum and electronics .. so please type slowly!
I have an old record deck (Systemdek) with a Phillips synchronous motor that is defunct and no longer manufactured. I know it is unserviceable as a multi meter shows open circuit between all three wires; the grey common feed and red and blue out. There is a very simple PCB that goes with the motor that consists of a power resistor, 6K8, to drop voltage to 110V from 220/240V for the motor and four capacitors. A friend lent me another multi meter which confirmed that the capacitors are as specified and I had already confirmed the resistor was fine. I can purchase a near identical (looking) motor from Farnell and few other sources all designed for turntable use and the same voltage and r.p.m .. BUT .. they specify a different capacitor capacitance from that which is on the present board.
I will not pretend to understand how this works but there is a capacitor on the blue outlet wire of the motor. This makes it rotate clockwise (apparently). Here is my question .. the original motor has a capacity of 0.82 micro farads (400V) on the PCBbut the replacement motor I can find specifies 0.22 micro farads. Of the three other capacitors, 2 seem to be spark suppressors for the main switch and the other links the non-motor side of the above directional capacitor to mains neutral.
If I buy the new motor and put it into the existing circuit to check that I've at least found the right solution to getting the table turning could I wreck the motor or would it just run less efficiently or perhaps at the wrong speed? There was a hint on the specification sheet for the new motor that a higher capacitance produced greater torque but could end up with a noisier motor .. so I guess a lower capacitance might be better for a turntable.. but perhaps the original manufacturers, who have moved on, took this into account? The motor will cost around 70 UK Pounds Sterling so I want to avoid damaging it before I have even started.
Grateful for any help.
I have an old record deck (Systemdek) with a Phillips synchronous motor that is defunct and no longer manufactured. I know it is unserviceable as a multi meter shows open circuit between all three wires; the grey common feed and red and blue out. There is a very simple PCB that goes with the motor that consists of a power resistor, 6K8, to drop voltage to 110V from 220/240V for the motor and four capacitors. A friend lent me another multi meter which confirmed that the capacitors are as specified and I had already confirmed the resistor was fine. I can purchase a near identical (looking) motor from Farnell and few other sources all designed for turntable use and the same voltage and r.p.m .. BUT .. they specify a different capacitor capacitance from that which is on the present board.
I will not pretend to understand how this works but there is a capacitor on the blue outlet wire of the motor. This makes it rotate clockwise (apparently). Here is my question .. the original motor has a capacity of 0.82 micro farads (400V) on the PCBbut the replacement motor I can find specifies 0.22 micro farads. Of the three other capacitors, 2 seem to be spark suppressors for the main switch and the other links the non-motor side of the above directional capacitor to mains neutral.
If I buy the new motor and put it into the existing circuit to check that I've at least found the right solution to getting the table turning could I wreck the motor or would it just run less efficiently or perhaps at the wrong speed? There was a hint on the specification sheet for the new motor that a higher capacitance produced greater torque but could end up with a noisier motor .. so I guess a lower capacitance might be better for a turntable.. but perhaps the original manufacturers, who have moved on, took this into account? The motor will cost around 70 UK Pounds Sterling so I want to avoid damaging it before I have even started.
Grateful for any help.