Rockwell Automation 1395 Digital DC Drive - Manual (Page 28)

Publication 2361-5.01 July 1998
1-16 Product Overview
Snubbers
Snubbers (resistor/capacitor assemblies) are installed in parallel with
the SCRs, working with the cell reactors to provide adequate voltage
suppression when the SCRs switch off.
Armature-Pulse Transformer Boards
Armature-pulse transformer boards provide the appropriate gate
voltage and current to trigger an SCR. In addition, these boards
provide gate driver isolation from the control logic. Figure 1.11
shows an armature-pulse transformer board.
DC Contactor
The main DC contactor is used to break the DC current to the motor
armature. Coil voltage to the contactor is controlled by contacts from
the pilot relay.
Figure 1.11
Armature Bridge Hardware
J2
J1
S ilicon-Controlled Rectifier
(SCR )
A n ode
C ath od e
G ate
Leads
A rm ature-Pulse Transform er
B oard
A n ode
Cath od e
G ate