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| | Tarih: 29.02.2008, 17:03 Mesaj konusu: sinema sistemlerinde kullanılan crown amplifikatör | |
| türkiye de hemen hemen bütün sinema sistemlerinde kullanılan crown amplifikatör şeması
Power Supply
The amplifier operates from nominal (off-load) +/- 65V (GB202), +/- 80V (GB402) or +/- 93V (GB602) supplies, with an auxiliary +/- 24V supply for the protection circuitry and the optional AMPSAP card. To generate the supplies, the mains transformer has one secondary with a centre tap, two 18Vac taps and the usual end taps. The end tap outputs are rectified by BR1 and smoothed by C1,C3,C5,C7 to get +HT and C2,C4,C6,C8 to get -HT (note: not all of C1-C8 are fitted on GB402 and GB202). The +/- 18Vac taps are rectified by D13-D16 and smoothed by C17 to get +24Vdc and C18 to get -24Vdc.
Soft Start System
AC mains enters the board on fastons (Red, Black, Blue) and leaves for the transformer by way of connectors Main1 (220/240) and Main2 (110/120). The soft start components are on the NEUTRAL line and comprise R22, PTC1, PTC2 and the contacts of RLY1. At switch on, R22 limits surge current and PTC1, PTC2 protect R22 from overheating. After a few seconds, the protection circuit energises RLY1 coil, closing RLY1 contacts which short out R22, PTC1, PTC2, allowing full power operation.
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