Adc; Standerd For Circuit Inspecpion And Adjustment - Yamaha CS-30 Service Manual

CS-30(S/*t 1001-)
Standerd for circuit inspecpion and adjustment
ADC Circuit Board
1. -15V Adjustment (+15V Adjustment)
Adjust[VRll until a voltage of —15.00V is present across —15V and E terminals. Then, make sure that a
voltage of +15 ± 0.15V is present across +15V and E terminals.
+ 10V Adjustment
AdjustfVR2]until a voltage of +10.00V is present across +10V and E terminals.
3. Load Characteristics
When no load is applied, the fluctuation should be smaller than ±0.5% and should show neither oscil¬
lation nor abnormal voltage.
Make sure that the regulator's response to load fluctuation is within 50m sec. When connecting Mylar
capacitors of 0.47/iF across each terminal and the E terminal, make sure that neither oscillation nor
abnormal voltage is generated and the response time is within 50m sec.
4. First Stage Voltage and Output Voltage
When load is fully applied, the output voltage fluctuation should be smaller than ±0.1% for the first
stage voltage fluctuation of ±15%, and the regulator should respond within 50m sec to a drastic change
in the first stage voltage.
5. Ripple Noise
When load is fully applied, make sure that ripple noise smaller than lOmVp-p is present at each output
terminal.
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