Yukon 2.5 x50 nvrs tactical night vision rifle scope, works fine but making a strange processing noise when on?

Hello, don't worry about it. It is HV to the image intensifier tube. The battery voltage goes through control circuit then to ccfl inverter (here is were dc voltage is switch on and off and switch dc voltage is step up by toroid coil that has two input and only two out puts). By impulsing the coil with two different switch dc voltage on the input this make the current lag the two different phase voltage by 90 degrees. Here is where the strange noise is coming from. The toroid coil is encased in iron case and if half of this iron case is loose, it makes case vibrate so the noise.


Now, the voltage come out of the toroid coil is switching dc (one could call it AC because that what AC voltage is, it switch between positive to negative) this voltage is about 300 to 900 switching DC voltage. This voltage will be applied to a 1/2 wave voltage multiplier (this voltage multiplier with have anywhere four four stages to 10 stages depend on what the input voltage to multiplier is.

Low the voltage out of the ccfl inverter the more stages the multiplier will have.



Now, the voltage multiplier will double the voltage per stage to need image intensifier tube voltage of 12000 to 45000 volts---DC switching or AC what ever one wants to call it. This voltage will bit you but it doesn't have a lot current associated with it, the current would be in the 10 to 15 ua (micro-amps) 1/10X6 amps.



Now, you know. GB...stewbison