TTI LD300 Service Manual page 30

Dropout Clamp operation (this is a functional check, not a calibration)
Select: Level Control = Level A. Input Enable = out, then in.
Set: Source voltage = 6 V.
Check: Unit is conducting 40 Amps.
Select: Meters = Slew & Dropout. Increase the Dropout setting to 5.8 Volts
Check: Unit is still conducting 40 Amps.
Select: Increase dropout setting slowly until Input lamp turns orange.
Check: Input lamp turns orange at a Dropout setting between 5.8 and 6.2 volts.
Current is <30 Amps; it may be zero.
Set: Dropout to zero.
Check: Current returns to 40 Amps.
Low current check
Set: Meters = Level A & Level B, reduce the Level A setting to 1.00 Amps.
Check: Load current is 1.0 A ± 30mA.
Select: Meters = Volts & Amps.
Check Current (RH) display shows 0.97 to 1.03
Amp mode setting calibration
Select: Mode = 8 Amps. Level Control = Level B
Meters = Level A & Level B, ensure Level B setting is 8.000
Meters = Volts & Amps, Enable = out, then in.
Adjust: VR34 for load current to be 8.000 Amps.
Check: Current (RH) display shows 8.00 ± .01 A.
Other High Current Modes
320 Watts mode setting calibration
Select: Enable = out, Control = Level A. Meters = Level A & Level B.
Adjust Level A setting to 4.000 Amps (while in 8A mode).
Mode = CP (constant power). Level A setting should read 160 watts.
Meters = Watts & Ohms, Enable = in.
Set: Supply output voltage to 10.0 V
Adjust: VR27 for watts (LH) display to read 160.0 Watts.
1 A/V mode setting calibration
Select: Enable = out, Mode = 1 A/V.
Meters = Level A & Level B, adjust Level A to 0.500 A/V.
Meters = Watts & Ohms, Enable = in.
Adjust: VR14 for Ohms (RH) display to read 2.000
40 A/V mode setting calibration
Connect: DVM to front panel input terminals
Set: Supply output voltage = 2.0 V
Select: Enable = out, Mode = 40 A/V, Enable = in.
Meters = Level A & Level B, ensure Level A is 20.00 A/V.
Set: Supply output voltage at load terminals to 2.000 V exactly (while current flowing),
using DVM.
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