24
Table 3-1. Control Board Test Connector, A2J7
PIN NO. SIGNAL NAME Vdc WAVEFORM/CONDITIONS SOURCE
Digital-Circuits Bias & Reference Voltages
1 +5V 5.0 A2Q3 (emitter)
22 + 20V(5V UNREG) 20.0 with 120Hz & 45KHz ripple A1CR6, A1CR7
14 2.5V ref 2.50 A2U9 (OUT)
6 0.5V ref 0.50 A2R79,A2R80
Analog-Circuits Bias Voltages
2 + 15V 15.0 A2U12 (OUT)
21 - 15V -15.0 A2U4 (OUT )
Status Signals
17 CV TTL Lo if in CV operation A2Q6C-7 (collector)
16 CC TTL Lo if in CC operation A2Q6F-14 (collector)
13 OV TTL Hi if not OVP shutdown A2U11D-11
11 DROPOUT TTL Hi if ac mains okay A2U17D-11
12 OT TTL Hi if not overtemp shutdown A2U11B-6
Control Signals
25 PWM OFF <0.5 1.7µs TTL pulses, 20KHz U1A-5
26 PWM ON <1.0 1.7µs TTL pulses, 20KHz U2B-6
18 Ip MONITOR <0.5 1V pk, ½ sawtooth, 20KHz A2CR26 (cathode)
8INHIBIT TTL hi if not remotely inhibited A2R185C, U19A-2
15 DOWN PROGRAM 1.2-3.0 A2CR21, A2CR27
7 OVP PROGRAM 1/10 OVP (6023A) e.g.: 2Vdc if OVP set to 20 A3R6 (wiper)
1/30 OVP (6028A)
5CLR OV +5V inverted OV reset line A7U29-5
19 2 PCLR +5V if +5V bias OK A2Q60-9
Commons & Current-Monitor
4 L COMMON 0.0 common return for all bias
voltages, and status and control
signals
A2C20 (-), A2R50,
A2U6-4
9 M COMMON 0.0 common return for 2.5V ref.
and 0.5V ref.
A2R83, A21-20
10 I-TEST ≈0.005 ( Iout) inboard-side monitoring res. A1R3,A1T2
3 NOT USED