User manual YORKVILLE AP4040 V2

[. . . ] Le point d'exclamation à l'intérieur d'un triangle équilatéral est prévu pour alerter l'utilisateur de la présence d'instructions importantes dans la littérature accompagnant l'appareil en ce qui concerne l'opération et la maintenance de cet appareil. S2125A FOLLOW ALL INSTRUCTIONS Instructions pertaining to a risk of fire, electric shock, or injury to a person CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COVER (OR BACK). REFER SERVICING TO QUALIFIED SERVICE PERSONNEL. Read Instructions: The Owner's Manual should be read and understood before operation of your unit. Please, save these instructions for future reference and heed all warnings. Packaging: Keep the box and packaging materials, in case the unit needs to be returned for service. [. . . ] R42 is in series with a 16 volt zener (ZD7) and is also in parallel with the junction of Q8. The current that flows through R20, ZD7, R42, and R22 normally saturates Q8. When Q9 reduces the voltage across ZD9 and R42 to below 16. 6 volts, Q8 turns off allowing a charge to build up on C8 through resistors R24 and R25. If current limiting occurs for a long enough duration to allow C8 to charge to 1. 2 volts then Q7 will turn on tripping the relay circuit on board M1147. As soon as the relay is tripped the audio signal will be turned off at the output of the voltage amplifiers and will remain off for about 5 seconds before the relay turns on and allows the audio signal to pass through the amplifier. If a current limit condition is still present then the whole cycle will occur again and repeat until the load conditions on the amplifier's output are safe for the amplifier. When a safe load appears the amplifier will automatically reset and drive that load (the speaker cabinet). The Second Tier and Tier Switching Refer to the simplified schematic Fig. One way of making an amplifier more efficient is to vary the Power Supply Voltage on the collectors of the output transistors (Q14 & Q22). The lower the voltage from collector to emitter, the lower the device dissipation. During quiescent conditions, there is 55VDC on the collectors of output transistors Q14 and Q22. The peak AC voltage that can appear on the amplifier's output is approximately 139V peak. The current limit circuit protecting the output transistors (Q13 to Q28) turns off and D204 and/or D205 are not forward biased and Q202 turns off. Through Q203 and Q201 the relay is turned back on and the voltage amplifiers are now active again, driving the output transistors. If the cause of current limiting (low impedance or short on the speaker output terminals) has been removed, then the amplifier will continue to operate normally. The third operation that the relay provides is "overheat shutdown". If for some reason the fan cannot keep the heatsinks in a safe operating temperature area then the fan control circuit (on board M1147) will deliver through D207 a positive current to turn Q203 on and turn Q201 off to turn off the relay and disable the voltage amplifiers. When the fan has cooled down the temperature of the amplifier, then the signal through D207 will disappear and the relay circuit will turn on the relay to resume normal operation. Anytime the relay is in the "protect" mode (due to the abnormal states) then contact pin 4 of the relay will illuminate LD3 (the protect LED on the front panel). Only test the triac for one protect cycle as prolonged testing will heat the triac to a high temperature. Soft Turn On Circuit To reduce the "inrush" current that flows through the line cord from the 120 VAC power source (typical with large linear power supplies), a circuit provides a soft turn on function. When the power switch is turned on, the current that initially flows through the primary of the transformer must flow through SG201 and SG202. After about 500 milliseconds a relay's contacts short across the surgestors so that they are not stressed by the current flowing through them under normal operation. A circuit consisting of Q240, Q241, C215, and the associated resistors provides the time delay for the turn on cycle of the relay. Refer to the section on the shutdown circuit for a circuit description. M1147 SHUTDOWN CIRCUIT, FAN CONTROL CIRCUIT, and SOFT TURN ON CIRCUIT: · The shutdown relay and its associated drive circuitry have two possible operating states. [. . . ] MOUNTING HARDWARE FOR Q40 AND Q41. #4060 SIL THERMO PAD HEATSPREADER PCB 10. MOUNTING HARDWARE FOR Q15A AND Q16A. #8701 4-40 HEX NUT #3851 SPCR Z234 CLAMP #8485 WASHER #8902 440- SCREW INITIAL TORQUE FOR TO-3'S IS 8 INCH/LB FINAL TORQUE AFTER HEATSINK HAS COOLED FROM WAVE SOLDER IS 6 INCH/LB #3896 HEATSINK 6. USE #2006 SMALL BODY 1R 1W FOR R33 AND R49. #4060 SIL-PAD #3501 WASHER 7. MOUNTING DETAILS FOR Q30 TRIAC USE #8799 TO MOUNT TRIAC Q30 PLACE CLAMP PIC HERE 1 #8865 4-40 SCREW 2 #3517 WASHER 1/4" BEND DOWN 1/4" FROM BODY OF THE TRANSISTOR IMPORTANT: AFTER MOUNTING DEVICE DO NOT CUT LEGS BEND LEGS IN DIRECTION SHOWN IT IS IMPRATIVE THAT LEG ARKED 2 AND 3 ARE BENT FLAT AGAINST THE COPPER SURFACE. 3 11. [. . . ]