Value 12Vdc
12Vdc

TM 11-6625-2958-14&P

be set much closer to the operating output voltage of the supply.

5-109MAXIMUM CROWBAR TRIP VOLTAGE

5-110 To adjust the maximum voltage at which the crowbar trips, proceed as follows:

a. Rotate A5R125 (OVERVOLTAGE ADJUST) and CURRENT controls fully clockwise.

b. Disconnect either end of R72 (TP70 or TP71; see Figure 7-10).

c.Connect decade resistance box in place of R95 (mounted on standoffs on main circuit board).

d.Turn on supply and adjust VOLTAGE con- trols for output voltage shown below:

Model 6259B 6260B

Model Value

6261B 23Vdc

6268B 45Vdc

6269B 45Vdc

e.Adjust decade resistance box until crow- bar trips (amber OVERVOLTAGE lamp lights up).

f.Replace decade resistance with appro- priate value resistor in R95 position and reconnect resistor R72. Maximum crowbar trip voltage is now set at voltage given in Step (d).

5-111CROWBAR DISABLEMENT

5-112 To disable the crowbar completely, disconnect either end of R98 (TP97 or TP98). This resistor is mounted on the main circuit board (see Figure 7-10).