| 摘要 |
A circuit to regulate the television track width comprises a first means of negative feedback (40, 54) coupled to a means of variable impedance which comprises a reactive variable impedance coupled to a shunt circuit which draws a charge current from it. The first negative feedback (40, 54) reacts to the charge current to produce a first negative feedback voltage. This voltage increases the value of the reactive impedance when the charge current increases to maintain an appreciably constant track width. The reactive impedance (45, 46, 47) comprises a driven commutator, whose conduction time varies in response to the first negative feedback voltage.
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