Ballast emi and shock hazard reduction

Claim 1

In an electrical system for operating at least one gaseous discharge lamp from a line voltage AC source and upon failure of the AC source, from a DC energized, high frequency emergency circuit, the improvement comprising: a ballast for operation from the AC source at high power factor, the ballast having means for reducing hazard associated with leakage current therein resulting from operation of the high frequency emergency circuit and for minimizing transference of EMI from the lamp side thereof to the AC source side thereof and to ground including an isolation transformer having at least a primary winding and a secondary winding; the secondary winding being divided into two portions; and a power capacitor connected serially in circuit between the two portions of the secondary winding.