SK103 connects to the micro controller and display PCB.
The 14 pin connector is numbered as follows:
No | Name | Type | Description |
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1 | +5V_D | O/P | 5 volt digital supply (for micro) | |
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2 | 0V_D | O/P | Digital ground |
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3 | +49V | O/P | Main power supply for VFD (via fusible resistor) | |
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4 | STANDBY | I/P | Mains relay control signal | (HIGH = ON) |
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5 | SPKR1 ON | I/P | Speaker 1 relay control signal | (HIGH = ON) |
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6 | SPKR2 ON | I/P | Speaker 2 relay control signal | (HIGH = ON) |
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7 | THERMPROT | O/P | Over temperature protect | (HIGH = FAULT) |
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8 | VIPROT | O/P | Short circuit protect | (HIGH = FAULT) |
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9 | DCPROT | O/P | DC offset protect | (HIGH = FAULT) |
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10 | AC PRESENT | O/P | Indicates AC mains is plugged in (HIGH = ON) | |
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11 | TRIGGER | O/P | 12V DC trigger input | (HIGH = ON) |
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12 | REMOTE | O/P | Demodulated RC5 remote input from rear panel | |
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13 | 0V_D | O/P | Spare digital ground pin |
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14 | +5V_D | O/P | Spare 5 volt digital supply pin | |
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The ground naming convention is as follows:
Name | Description |
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0V_D | Digital ground (used for micro processor circuitry, display and interface) |
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0V_LS_R | Right channel loudspeaker ground return |
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0V_SIG | Signal ground (this is the ‘clean’ precision reference ground) |
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0V_PSU | Power supply ground (high current pulses for the large reservoir caps) |
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0V_TRIG | Ground return for the jack socket trigger and remote control circuit |
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0V_HF_R | Decoupling ‘noisy’ ground for the right channel power amp |
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0V_LS_L | Left channel loudspeaker ground return |
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0V_HF_L | Decoupling ‘noisy’ ground for the left channel power amp |
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