KEPCO BOP 72-3DL Modification Sheet

MODIFICATION OF STANDARD

KEPCO®

KEPCO MODEL BOP 72-3ML
KEPCO MODEL BOP 72-3DL

THE POWER SUPPLIER™

The Kepco Models BOP 72-3ML and BOP 72-3DL have been modified from standard Kepco
Models BOP 72-3M and BOP 72-3D, respectively, to be stable handling inductive loads up to 1
Henry.

INSTRUCTION MANUAL CORRECTIONS:

This modification makes the BOP more suitable for a wide variety of applications such as
motor testing, testing of magnetic components (coils, speakers, etc.), industrial applications
with inductive loads, driving CRT coils, cryogenic applications and powering correcting magnets
for medical imaging applications or particle accelerators. The unit is designed to operate in a
stable manner in Current or Current Limit Mode for loads up to 1 Henry. They are also stable
with any R-L series load combination.

All specifications of the unit in voltage mode are unchanged from the standard model. Spec­ifications listed in Table 1 are for BOP 72-3ML and BOP 72-3DL in Current Mode. All other
specifications are identical to the standard BOP.

TABLE 1. BOP 72-3ML AND BOP 72-3DL SPECIFICATIONS

Bandwidth (DC to f-3dB)

Resistive

Load, Nominal

4.5 KHz 4.5 KHz 80

NOTES:
(1) Specifications listed are for Current Mode. All other specifications are identical to the standard

BOP.
(2) 10%-90%, short-circuit.
(3) Short-circuit - Nominal Resistive Load.
(4) Load effect increases nonlinearly with frequency from the typical 0.5 mA in DC- full scale (same

as the standard unit) with the average rate listed.

Inductive

Load, 2mH

Rise/Fall Time

(2)

µS200µS 28 ppm/Hz

Recovery

at

Step Load

(3)

Load Effect

Nominal Resistive Load

(4)

In current mode the bandwidth is reduced when operating with a resistive load. Correspond-

ingly, the rise and fall time of the unit is increased.

BOP 72-3ML/DL-r2/031512

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

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

If the load impedance at the working frequency multiplied by the peak value of current
equals the voltage limit setting, it is recommended that the output voltage be kept below the
voltage limit setting to avoid inducing a large distortion of output current. If the voltage limit is
reached, the unit’s bandwidth can be reduced by connecting an external film capacitor between
pins 16 and 18 of the unit's programming connector (PC 12). Table 2 below shows the effect
that adding the external capacitor has on the 3dB bandwidth for resistive, resistive-inductive or
inductive loads, with less than 10% tolerance (excluding the capacitor tolerance)

TABLE 2. BANDWIDTH CORRECTION

EXTERNAL CAPACITOR

(ACROSS PINS 16 AND 18 OF PC 12 PROGRAMMING CONNECTOR)

0.01

µF0.02 µF 0.05 µF0.1 µF0.2 µF0.5 µF1 µF

CORRECTED BANDWIDTH 2.4 KHz 1.7 KHz 0.8 KHz 0.52 KHz 0.27 KHz 0.12 KHz 0.06 KHz

2 BOP 72-3ML/031512