BEHLMAN BL20000 Series, User'S Manual And Technical Reference Manual

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BL20K SERIES REV E 2013
5.7.2 The optional GPIB board provides an isolated computer interface for remote control of frequency, voltage,
and the output relay. The GPIB card will also provide read back of current and voltage to the GPIB.
5.7 IGBT DRIVER
The insulated gate bipolar transistor (IGBT) driver is a hybrid IC that is used in the over current detector circuit
of each BL20000 unit. Two of these drivers are used in each unit to provide signal isolation, over current
detection, and low-speed over current cutoff features. Figure 1 shows the internal parts of an IGBT driver and
its pin descriptions.
SIGNAL ISOLATION - A photo-coupler with a high isolation voltage is used for signal isolation.
OVER CURRENT DETECTION - The IGBT driver can withstand an over current of 10 µsec duration when
short circuited. An extremely fast protection circuit is used here for this reason.
LOW-SPEED OVER CURRENT CUTOFF - A low-speed cutoff circuit slowly turns off the IGBT driver in
response to an over current sensing. This feature protects the driver against damage from high voltage spikes
generated during normal drive speed cutoffs.
PIN DESCRIPTION
1 Connected to smoothing
capacitor for reverse bias
power supply.
2 Power supply (+20 Vdc).
3 Drive output.
4 Not connected.
5 Over current detection
output.
6 Collector voltage
monitoring.
7,8 Not connected.
9 Power supply (0 Vdc).
10-13 Not connected.
14 Drive signal input (-).
15 Drive signal input (+).
Figure 5-3 IGBT Driver, Pin Description
and Schematic