Using a SON with nothing connected

[Russell]

Are any precautions necessary if riding with a SON if no lights are connected?  The spec sheet says high voltages are generated so I'm not going to lick the contacts while riding.  I guess it is the same scenario with the lights switched off except the bare contacts are hidden.

R

[andrew_s]

No precautions are needed.
If you attempted to finger the hub contacts when riding, the spokes would be more of a problem than the voltage, and as far as the hub is concerned, it's the same as a turned-off light.

[Biggsy]

How about wiring it up to your mouth to get that strangely interesting taste of electricity across your tongue?

[MartinC]

If it's not connected then I'd dispute that you're using it.  Semantics are allowed when the real question has already been answered.

[Whitedown Man]

How about wiring it up to your mouth to get that strangely interesting taste of electricity across your tongue?

Sounds better - and possibly more effective - than gels

[Russell]

If it's not connected then I'd dispute that you're using it.

If it is keeping the front forks off the road then surely it has a use and is being used.

Granted it is not being used to its full potential, but then again what does.

 

[Kim]

The real question is whether the rolling resistance is higher with the terminals shorted or O/C...   

[aidan.f]

Open circuit voltages (son classic) are in the order of 70 to 80 volts peak, which would be noticable but probably not fatal.
This Voltage will  cause  failure of badly designed light and acessory regulators. Shorting the hub causes no damage and  reduces rolling resistance the method used in better designed regulators.
 

[Samuel D]

By what mechanism is drag reduced by shorting the terminals, aidan.f?

[andrew_s]

Back in the days before LEDs, I had 2 halogen lights wired in via a switch box that had a switch for each light, allowing left, right, left+right or neither light to be in use. The normal "short out the secondary" approach to twin lights results in instant darkness and a mandatory bulb change if the primary bulb blows.

For the first couple of months, I'd got the switches wired up wrongly, so "both off" was actually both shorted. It was quite noticeable that there was extra handlebar vibration, once I paid attention.

[Kim]

By what mechanism is drag reduced by shorting the terminals, aidan.f?

Reduction of eddy currents, presumably.

[The French Tandem]

Open circuit voltages (son classic) are in the order of 70 to 80 volts peak, which would be noticable but probably not fatal.
This Voltage will  cause  failure of badly designed light and acessory regulators. Shorting the hub causes no damage and  reduces rolling resistance the method used in better designed regulators.

I'm not an electrical expert, but if I remember correctly, from my college years, shorting a voltage source should result in a (theoretically) infinite current, which is presumably harmful to whichever bit of the hub it passes through. Have I missed something?

[andrew_s]

A dynohub behaves more like a current source. There will be a bit over a half amp though the hub windings if shorted.

Whether that half amp dissipates more power than any open circuit eddy currents, I leave to those who know more than me.

[The French Tandem]

Thank you!

[Biggsy]

Never mind all that.  What about the poor slug or other small moist creature who climbs onto the contacts?  There's a reason to insulate!  We must not condone animal cruelty on The Knowledge.

[Plug1n]

Surely a high watt, 1 ohm resistor across the terminals would be an important contribution to the training programme?

[Veloman]

Surely a high watt, 1 ohm resistor across the terminals would be an important contribution to the training programme?

Riding with the light on is the best contribution to the training programme IMO.

[Biggsy]

And that saves the slug.  Good thinking, Veloman. 

[Plug1n]

Surely a high watt, 1 ohm resistor across the terminals would be an important contribution to the training programme?

Riding with the light on is the best contribution to the training programme IMO.

I suppose my suggestion was not so bright ......