RELAY PROTECTION FOR HAFLER 200 SERIES AMPS
The Speaker Protection Circuit Board has two main functions:
to protect the audio amplifier and the loudspeakers during start-up sequence
when the amplifier might output DC voltage, and to protect the loudspeakers in
the unlikely event of an amplifier power stage failure, where DC component
would damage the speaker.
The circuit is a simple discrete design
incorporating 3 transistors, 3 diodes,
and 1 Zener diode. Relay power is derived from the AC secondary across one AC
Terminal of the Rectifier. This is required for quick relay disengagement when
amp is shut down or power failure occurs. Approximately a 3-second Turn-On Delay is created by a
simple RC circuit. DC Output Monitoring is accomplished using positive and
negative low pass detectors triggering when DC is present in the amplifier
output above +/- 1 volt for an optimized time constant. Left and right channel
impedance is offset for circuit compatibility use with bridged amplification.
Two separate 24-volt Relays in series (20-amp min. rated contacts) ensure two
channel disengagement if one fails. The
relay circuit also incorporates a
resettable PTC fuse. Created to work
with the Hafler 200 series amplifiers. Designed in the USA.
THIS KIT MAY BE INSTALLED IN HAFLER ORIGINAL 200 SERIES POWER AMPLIFIERS TO ENABLE EASY RELAY PROTECTION WITH DELAYED TURN ON CONVERSION. COMES WITH INSTRUCTIONS AND 36 COLOR PICTURES FOR REFERENCE ON USB FLASH DRIVE.
THERE
ARE THREE BASIC RULES FOR SUCCESS IN ELECTRONIC KIT BUILDING:
1. READ
THE INSTRUCTIONS CAREFULLY AND FOLLOW THEM
2. MAKE
SECURE SOLDER CONNECTIONS WHICH ARE BRIGHT AND SMOOTH
3. CHECK
YOUR WORK CAREFULLY AFTER EACH STEP
FATIGUE
INCREASES THE RISK OF ERROR, SO TAKE A BREAK RATHER THAN PUSH FOR EARLY
COMPLETION. YOUR WORK AREA SHOULD HAVE GOOD LIGHTING, THE PROPER TOOLS, AND A
PLACE WHERE THE PICTORIAL DIAGRAMS CAN BE VIEWED WITHIN EASY REACH FOR
CHECKING. THE TOOLS SHOULD INCLUDE:
A 40 TO
100 WATT SOLDERING IRON WITH 3/16 OR ¼ TIP WHICH CAN REACH AT LEAST 600 DEGREES
F.
ROSIN
CORE SOLDER (SUPPLIED)
A DAMP
SPONGE OR CLOTH TO WIPE THE TIP OF THE IRON
A WIRE
STRIPPING TOOL FOR REMOVING INSULATION FROM 26GA TO 16GA WIRE
A
MEDIUM-BLADE SCREWDRIVER SET OR 4 IN 1 SCREWDRIVER
NEEDLE-NOSE
PLIERS
SMALL
DIAGONAL OR SIDE-CUTTING PLIERS
PLIERS
NUT
DRIVERS OR MINI SOCKET SET
NOTE:
BEFORE PERFORMING THE UPGRADE, MAKE SURE THE POWER SUPPLY AND AMPLIFIER ARE IN
SOUND WORKING ORDER. QUA-CO
LLC ASSUMES NO RESPONSIBILITY FOR IMPROPER ASSEMBLEY, FUSING OR INSTALLATION
CAUSING AMP OR SPEAKER FAILURE. IF YOU ARE INTERESTED IN
HAVING THIS UPGRADE INSTALLED PROFESSIONALLY BY A QUALIFIED ENGINEERING
SERVICE, PLEASE EMAIL ME FOR CONTACT INFORMATION.
THANKS FOR LOOKING.