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Setup. The Main Troubleshooting Setup, Page 53, except connect the external supply to the unit's + OUT ( + ) and - OUT
(-) terminals. Apply the ac mains voltage to the isolation transformer. Adjust the unit's OVP limit to 10Vdc. Set the external
supply (EXTERNAL) as instructed below.
Outputs:
NODE ( - ) = A2J7-4
SET VOLTAGE
NODE ( + ) EXTERNAL (Vdc) SETUP MEASUREMENT
A2U7-2 - 2.5Vdc
A2J7-7 - 0.1V (6030A)
1.0V (6031A)
0.33V (6032A)
0.04V (6035A)
A2J7-5 - 4.5Vdc
A2J7-13 5 Hi
A2J7-13 15 Lo
A2J7-13 5 Lo
A2J7-13 5 cycle power Hi
Note: Connecting a test probe to either input of either comparator in the OV Flip Flop (pins A2U8-1, 6, 7,10,11
or 13 ) may cause the flip flop to change states and cause the probed input to be low.
Troubleshooting PWM & Clock
The inputs to gates A2U18A and A2U18B are the keys to PWM troubleshooting. The 20KHz Clock starts each PWM
output pulse, and the pulse stops when any of the inputs to A2U18A or A2U18B goes low. The PWM is inhibited and
prevented from initiating output pulses as long as any of the seven inputs is low.
Circuit Included. Pulse Width Modulator (PWM), Off-Pulse One shot, On-Pulse Oneshot, 20KHz Clock.
Setup. The Main Troubleshooting Setup, Page 53. Apply the ac mains voltage to the isolation transformer. Adjust the unit's
current setting above 1.0 Adc. Set the external supply (EXTERNAL) and adjust the unit's voltage setting (INTERNAL) as
instructed below.
Inputs:
NODE ( - ) = A2J7-4
NODE ( + ) SETUP MEASUREMENT SOURCE
A2J7-24 5.0Vdc A2Q9, A2W3
A2U18-9 Hi Remote Inhibit
A2U18-10 Hi A2U15-10
A2U18-12 Hi A2U15-13
A2U18-13 Hi A5TS1, A4TS1
A2U18-5 Hi A2U18-8
A2U18-2 Hi A2U8-2
A2U18-1 set OUTPUT
ADJUST for 1Vdc
Hi A2U10-7