KEPCO BOP 20-5DL Modification Sheet

MODIFICATION OF STANDARD

KEPCO®

KEPCO MODEL BOP 20-5ML
KEPCO MODEL BOP 20-5DL

THE POWER SUPPLIER™

The Kepco Model BOP 20-5ML and BOP 20-5DL have been modified from a standard Kepco Model
BOP 20-5M and BOP 20-5D, respectively, to allow the unit to work with inductive loads (up to 1H) in Cur­rent mode.

1) ELECTRICAL CHANGES (BOP A1 BOARD):

A. At BOP A1 board, interrupt connection between IC11 pin 3 and P4, pin 10, then add R100 (P/N

115-1822, 1K Ohms, 1%, 1/4W) between IC11 pin 3 and P4, pin 10.

B. At BOP A1 board, add series combination of R101 (P/N 115-1857, 49.9K Ohms, 1%, 1/4W) and

C37 (P/N 117-0588, 4700pF, 10%, 200V) between IC11, pin 3, and the junction of R71 and RN2.

C. At BOP A1 board, add series combination of R102 (P/N 115-1857, 49.9K Ohms, 1%, 1/4W) and

C38 (P/N 117-0588, 4700pF, 10%, 200V) between IC9, pin 3, and the junction of R71 and RN2.

D. At BOP A1 board, change C21 to P/N 117-0377 (22nF, 10%, 200V).

2) MECHANICAL CHANGES:

None

3) BOP INSTRUCTION MANUAL CORRECTIONS:

A. Unit designed to work with inductive loads (up to 1H) in Current or Current Limit modes. The unit will
be stable with any R-L series load combination.

B. To avoid inducing a large distortion of output current It is recommended that the output voltage be kept
below the voltage limit setting if the load impedance at the working frequency multiplied by the peak
value of current equals the voltage limit setting. If the voltage limit is reached, it is recommended that the
unit’s bandwidth be reduced by connecting an external film capacitor between pins 16 and 18 of the unit's
PC12 connector; refer to Table 1 to change the 3dB bandwidth for resistive, resistive-inductive or induc­tive loads, with less than 10% tolerance (excluding the capacitor tolerance).

TABLE 1. 3dB BANDWIDTH CORRECTION IN CURRENT MODE

C

(uF) 0.01 0.02 0.05 0.1 0.2 0.5 1

EXT

BANDWIDTH (KHz) 4.2 2.4 1.1 0.55 0.28 0.12 0.06

C. Characteristics changed as follows:

Bandwidth (DC to f-3dB)

Current Mode (Nominal Resistive Load): 12.8 KHz
Current Mode (Inductive Load, 2mH): 7.9 KHz

Rise/Fall time (10%-90%, Nominal Resistive Load)

Current Mode: 30

Recovery at Step Load

Current Mode: 270

Load Effect

Current Mode (Nominal Resistive Load):

Increase with frequency from the typical 0.5 mA in DC- full scale (same as the
regular unit) with 3.5 ppm/Hz (of the low frequency output current value)

µS

µS (Short-circuit - Nominal Resistive Load)

BOP20-5ML/DL/081213

KEPCO, INC. ! 131-38 SANFORD AVENUE ! FLUSHING, NY. 11355 U.S.A. ! TEL [phone] ! FAX [phone]

email: [e-mail] ! World Wide Web: http://www.kepcopower.com