loewe f875 sensotronic chassis f800 11

Posted on Feb 7, 2014

The LOEWE F875 SENSOTRONIC CHASSIS 543/490 is realized with the F800 LOEWE Chassis serie and in the Line / Horizontal deflection output like a COLOR TELEVISION CHASSIS with EHT output with Tripler and Horizontal output with thyristor tech. LOEWE-OPTA Start-delay overload protection arrangement for a thyristor sweep circuit:An input switching thyri

loewe f875 sensotronic chassis f800 11
Click here to download the full size of the above Circuit.

stor of a deflection circuit is selectively excited at a sweep rate by a transistorized driver stage. A separate protective thyristor is disposed in a DC power source that supplies operating bias to the driver stage and to the switching thyristor via a supply capacitor. Initially, the supply capacitor is partially charged through a high-ohmic shunt resistor that budges the protective thyristor, whose control electrode is coupled to the output of the switching thyristor. A portion of the resulting voltage across the partially charged supply capacitor is applied via a voltage divider and a Zener diode to the base of a threshold-operated transistor that normally blocks the driver stage. When the supply capacitor has charged to a predetermined minimum value necessary to assume turn-on of the protective thyristor, the threshold-operated transistor is triggered to permit the driver stage to operate the switching thyristor at the sweep rate. The resulting turn-on of the protective thyristor permits the rapid completion of charge of the supply capacitor to its normal operating voltage, and thereafter provides full overload protection for the deflection circuit. 1. In a communications receiver wherein (a) a first input switching thyristor of a deflection circuit in the receiver is pulsed at a sweep rate by a driver stage when the latter is excited, (b) a supply capacitor is chargeable through a second protective thyristor by-passed...

Leave Comment

characters left:

Related Circuits

  • New Circuits



    Popular Circuits

    Multitone Siren Alarm circuit diagram
    simple lamp dimmer 220v using triac
    Open Charge Regulator
    The current loop interface circuit diagram of AD694 being used as D / A converter