EHT and Line Scan Regulator Circuit
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-04
The circuit described regulates both EHT (extra high tension) and line scan for a CRT by using a power operational amplifier in a feedback loop. In addition to the flyback transformer used in a conventional EHT circuit, an additional transformer controls the amplitude of the flyback pulse to regulate EHT and provide dynamic linearity correction for line scan. Fig. 1 shows an EHT regulator circuit. Consider first the circuit to the right of capacitor C, which is similar to a conventional flyback generated EHT circuit. A small transformer T1 is used in series with the flyback transformer (FBT); the former is wound with a 1:1 ratio so that its inductance is about 10% of the FBT.