[tech] Coke machine lights, empty detection, fans

[Harry]

Nick Bannon wrote:

> So... it turns out that the neon lights are driven with a normal clean
> looking sine wave, measured as 288V peak-to-peak with the oscilloscope,
> at about 6mA.
> 
> Does that mean we've got a low power factor to be reading it as 100VAC
> with a standard multimeter? and that things are burning out because we're
> underrated for the actual peak-to-peak?

Hi Nick

I think your meter is correctly measuring 100VAC RMS. The conversion is:
Vpk-pk = Vrms * 2 * root2
(for a sine wave) so 288 volts pk-pk agrees with that.

More:  http://en.wikipedia.org/wiki/Root_mean_square

Neons are typically 70V but very maybe they have been replaced and are a lower
voltage part and/or the limiting resistor is a bit low ?

Did they used to fail prior to installing the empty detector cct ?

Harry