Techfix
20-April-2006, 03:00 AM
I need answers on some theorys i have with HV corona discharge.
I have a problem with an installation of Powder coating guns. We keep blowing the cascades (in the guns).
Essentially they consist of a transformer and capacitor bank that has high frequency square wave 15VDC (fired by FET's) passed through through it, amplifying the voltage up to -100KV @ 100uA.
The voltage and current are controlled by modulating the input frequency.
What happens is the cascades fail, to emmit voltage (or current), I suspect the Caps inside are failing, however I have not been able to prove this as the whole thing is encased in resin.
Would there be a massive corona field being produced, (the guns are spaced approx 150mm apart) and would this corona field be discharging through the casadces? (backtracking).
By the way, all guns have independant power supplies. Could these be fighting each other (they independantly regulate voltage and current), or rather they woud be switching from V reg to I reg modes constantly.
Would if one gun was set @ -100KV (they are negatively charged) and another set @ say -70KV, would the one with greater potential be absorbing current from the lower?
As the whole setup is reciprocating up to 9 metres in the air, there may be massive flux "air gap" capacitor being formed could this be possible?
Can any body shed light on this subject? :confused:
I have a problem with an installation of Powder coating guns. We keep blowing the cascades (in the guns).
Essentially they consist of a transformer and capacitor bank that has high frequency square wave 15VDC (fired by FET's) passed through through it, amplifying the voltage up to -100KV @ 100uA.
The voltage and current are controlled by modulating the input frequency.
What happens is the cascades fail, to emmit voltage (or current), I suspect the Caps inside are failing, however I have not been able to prove this as the whole thing is encased in resin.
Would there be a massive corona field being produced, (the guns are spaced approx 150mm apart) and would this corona field be discharging through the casadces? (backtracking).
By the way, all guns have independant power supplies. Could these be fighting each other (they independantly regulate voltage and current), or rather they woud be switching from V reg to I reg modes constantly.
Would if one gun was set @ -100KV (they are negatively charged) and another set @ say -70KV, would the one with greater potential be absorbing current from the lower?
As the whole setup is reciprocating up to 9 metres in the air, there may be massive flux "air gap" capacitor being formed could this be possible?
Can any body shed light on this subject? :confused: