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optimal voltage for heating stylus?
I'm working on this record cutter stuff and want to set up some handy stylus heating. Got the nichrome wire but would like to know the proper voltage range for heating. Can anyone help?
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Hi,
I prefer to control the current rather than the voltage. The exact value varies based on the individual cutting stylus and the speed and material being cut. The normal procedure is to cut a silent groove test cut and raise the current until the noise drops to a minimum. If you purchase an off the shelf stylus, they will give some general guidlines. Something on the order of 500ma. is in the range. If you plan to wind you own, you'll need to experiment a bit. The good news is that if you happen to burn out the heater, you can just re-wind. If you go too far, with the heat, the noise will increase and you run the risk of the chip flashing or smoking.
I have a copy of the Bachman paper from 1950 titled "Columbia Hot Stylus Technique". This has some tech info on the process. If you PM with you email, I can send you a copy (its a set of 3 scanned jpg pages about 800kb each).
Mark
I prefer to control the current rather than the voltage. The exact value varies based on the individual cutting stylus and the speed and material being cut. The normal procedure is to cut a silent groove test cut and raise the current until the noise drops to a minimum. If you purchase an off the shelf stylus, they will give some general guidlines. Something on the order of 500ma. is in the range. If you plan to wind you own, you'll need to experiment a bit. The good news is that if you happen to burn out the heater, you can just re-wind. If you go too far, with the heat, the noise will increase and you run the risk of the chip flashing or smoking.
I have a copy of the Bachman paper from 1950 titled "Columbia Hot Stylus Technique". This has some tech info on the process. If you PM with you email, I can send you a copy (its a set of 3 scanned jpg pages about 800kb each).
Mark
While cutting an unmodulated groove, drop the pickup stylus in the newly forming groove and turn up the stereo... Add current slowly, listening for the hiss level to lessen. Keep adding current until the audibility of the hiss gets no lower, no matter how much more heat is applied. Then return to the point of least current that achieves this level of quietude. Too much heat causes horns to form on the edges of the rills. This is bad for plating. Too little heat at the outset can lead to audible noise during the slower groove playback, at the inner radii.
Also, you'll want to have excellent swarf removal, since the heated stylus can easily ignite the lacquer string.
On the last Apollo blank I checked, it was about 0.1 A, although the rheostat on my lathe goes up to 1.0 A. Doing this on the outside edge of the disc allows for the effective radius of a target pressing to be cut with newly calibrated stylus heat.
- Nas L. Venturi
P.S., don't forget you'll also need an eye dropper, fish scale, spirit level, dial indicator, machine oil, microscope with reticule, helium tank with regulator, ganged attenuators, blanks, acetone, nitric acid...
Also, you'll want to have excellent swarf removal, since the heated stylus can easily ignite the lacquer string.
On the last Apollo blank I checked, it was about 0.1 A, although the rheostat on my lathe goes up to 1.0 A. Doing this on the outside edge of the disc allows for the effective radius of a target pressing to be cut with newly calibrated stylus heat.
- Nas L. Venturi
P.S., don't forget you'll also need an eye dropper, fish scale, spirit level, dial indicator, machine oil, microscope with reticule, helium tank with regulator, ganged attenuators, blanks, acetone, nitric acid...
Hi,
I use a regulated supply in constant current mode. The voltage is whatever it needs to be to prouduce the desired current. My supply is only 0-7.5 Volts 0-3A (HP 6203B). This is probably overkill, but I got it so cheaply <$50, that its a no brainer for me. As long as you can monitor current in the range of 0-1A and have a reasonable reserve of voltage (5-6 Volts is probably enough), you should be good to go. BTW, it does not have to be DC to work.
Mark
I use a regulated supply in constant current mode. The voltage is whatever it needs to be to prouduce the desired current. My supply is only 0-7.5 Volts 0-3A (HP 6203B). This is probably overkill, but I got it so cheaply <$50, that its a no brainer for me. As long as you can monitor current in the range of 0-1A and have a reasonable reserve of voltage (5-6 Volts is probably enough), you should be good to go. BTW, it does not have to be DC to work.
Mark
The NiChrome wire has a very low heat factor, so its resistance will not significantly change when heated - this is one of the reasons it is used - that, and that it is a good dissipater. What about the rest of the circuit?folk wrote:yes, I understand all of this. But you can't exactly raise the current without having a voltage to begin with. So, my question again is; what is the optimal voltage range for the heating wire.
you've got .1a but is your voltage source 6v, 12v, 20v or what?
thanks
Is the NiChrome wire about 15 Ohms per foot? Do you need about 1/3' to wind around the stylus several times and have a little left over on each end? If there were no other source of resistance in circuit and you wanted to have around 0.5 A, you could use the relationship for Voltage, E = IR, and see that you would need to apply (0.5 A x 5R =) 2.5 Volts to this hypothetical circuit. If you add a pot and any other devices, such as a way to read the applied current, you will gain more resistance and require increased voltage. You should be straight with any wall wart and a variac, provided you can measure the current.
- Doug Intuit