Spellman EPM Series, SMS Series Instruction Manual

R

EPM/SMS SERIES

MODEL :
SERIAL# :
DATE :

SPELLMAN
HIGH VOLTAGE ELECTRONICS
CORPORATION

475 Wireless Blvd.
Hauppauge, New York, 11788

[phone]*FAX: [phone]*
E-mail: [e-mail]
Website: www.spellmanhv.com

High Voltage Power Supply

EPM/SMS MANUAL 118027-001 Rev G

WICHTIGE SICHERHEITSHINWEISE

SICHERHEIT

DIESES HOCHSPANNUNGSNETZTEIL ERZEUGT LEBENSGEFÄHRLICHE HOCHSPANNUNG.

SEIN SIE SEHR VORSICHTIG BEI DER ARBEIT MIT DIESEM GERÄT.

Das Hochspannungsnetzteil muß immer geerdet sein.

Berühren Sie die Stecker des Netzteiles nur, wenn das Gerät ausgeschaltet ist und die elektrischen

Kapazitäten des Netzteiles und der angeschlossenen Last entladen sind.

Die internen Kapazitäten des Hochspannungsnetzteiles benötigen ca. 5 Minuten, um sich zu entladen.

Erden Sie sich nicht, und arbeiten Sie nicht in feuchter oder nasser Umgebung.

SERVICESICHERHEIT

Notwendige Reparaturen können es erforderlich machen, den Gehäusedeckel während des Betriebes zu

entfernen.

Reparaturen dürfen nur von qualifiziertem, eingewiesenem Personal ausgeführt werden.

“WARNING” im folgenden Text weist auf gefährliche Operationen hin, die zu Verletzungen oder zum Tod

führen können.

“CAUTION” im folgenden Text weist auf Prozeduren hin, die genauestens befolgt werden müssen, um

eventuelle Beschädigungen des Gerätes zu vermeiden.

118004-001 REV. B

PRECAUTIONS IMPORTANTES POUR VOTRE SECURITE

CONSIGNES DE SÉCURITÉ

CETTE ALIMENTATION GÉNÈRE DES TENSIONS QUI SONT DANGEUREUSES ET PEUVENT ÊTRE FATALES.

OYEZ EXTRÊMENT VIGILANTS LORSQUE VOUS UTILISEZ CET ÉQUIPEMENT.

S

Les alimentations haute tension doivent toujours être mises à la masse.

Ne touchez pas les connectiques sans que l’équipement soit éteint et que la capacité à la fois de la charge et de

l’alimentation soient déchargées.

Prévoyez 5 minutes pour la décharge de la capacité interne de l’alimentation.

Ne vous mettez pas à la masse, ou ne travaillez pas sous conditions mouillées ou humides.

CONSIGNES DE SÉCURITÉ EN CAS DE REPARATION

La maintenance peut nécessiter l’enlèvement du couvercle lorsque l’alimentation est encore allumée.

Les réparations doivent être effectuées par une personne qualifiée et connaissant les risques électriques.

Dans le manuel, les notes marquées « WARNING » attire l’attention sur les risques lors de la manipulation de ces

équipements, qui peuvent entrainer de possibles blessures voire la mort.

Dans le manuel, les notes marquées « CAUTION » indiquent les procédures qui doivent être suivies afin d’éviter

d’éventuels dommages sur l’équipement.

118004-001 REV. B

IMPORTANTI PRECAUZIONI DI SICUREZZA

SICUREZZA

QUESTO ALIMENTATORE GENERA TENSIONI CHE SONO PERICOLOSE E

POTREBBERO ESSERE MORTALI.

PONI ESTREMA CAUTELA QUANDO OPERI CON QUESO APPARECCHIO.

Gli alimentatori ad alta tensione devono sempre essere collegati ad un impianto di terra.

Non toccare le connessioni a meno che l’apparecchio sia stato spento e la capacità interna

del carico e dell’alimentatore stesso siano scariche.

Attendere cinque minuti per permettere la scarica della capacità interna dell’alimentatore

ad alta tensione.

Non mettere a terra il proprio corpo oppure operare in ambienti bagnati o saturi d’umidità.

SICUREZZA NELLA MANUTENZIONE.

Manutenzione potrebbe essere richiesta, rimuovendo la copertura con apparecchio

acceso.

La manutenzione deve essere svolta da personale qualificato, coscio dei rischi elettrici.

Attenzione alle AVVERTENZE contenute nel manuale, che richiamano all’attenzione ai

rischi quando si opera con tali unità e che potrebbero causare possibili ferite o morte.

Le note di CAUTELA contenute nel manuale, indicano le procedure da seguire per evitare

possibili danni all’apparecchio.

118004-001 REV. B

EPM/SMS MANUAL i 118026-001 REV K

Table of Contents

PAGE

1. INTRODUCTION

1.1 Description of the EPM/SMS Series....................................................................1

1.2 EPM/SMS Specifications ....................................................................................1

1.3 Standard Features .................................................................................................2

1.4 Options .................................................................................................................2

1.5 Interpreting the Model Number ...........................................................................2

2. INSPECTION & INSTALLATION

2.1 Initial Inspection ..................................................................................................3

2.2 Mechanical Installation ........................................................................................3

2.3 Installation Instructions ........................................................................................6

3. OPERATING INSTRUCTIONS

3.1 Operation ..............................................................................................................7

3.2 Standard Features .................................................................................................8

4. PRINCIPLES OF OPERATION

4.1 High Frequency Inverter ......................................................................................15

4.2 High Voltage Circuits ..........................................................................................15

4.3 Control Circuits ....................................................................................................15

4.4 Options .................................................................................................................15

5. OPTIONS

5.1 Floating Ground ...................................................................................................16

5.2 24Vdc ...................................................................................................................16

5.3 No Slow Start .......................................................................................................16

5.4 Non-Standard Slow Start .....................................................................................16

5.5 Extra Length Output Cable ..................................................................................16

5.6 Custom Designed Models ...................................................................................16

6. MAINTENANCE

6.1 Periodic Servicing ................................................................................................18

6.2 Performance Test .................................................................................................18

6.3 High Voltage Dividers .........................................................................................18

EPM/SMS MANUAL ii 118026-001 REV K

7. REPLACEMENT PARTS

7.1 Replacement Parts ................................................................................................19

7.2 Correspondence and Ordering Spare Parts ..........................................................19

8. FACTORY SERVICE

8.1 Warranty Repairs .................................................................................................20

8.2 Factory Service Procedures ..................................................................................20

8.3 Ordering Options and Modifications ...................................................................20

8.4 Shipping Instructions ...........................................................................................20

APPENDIX

A. Specification Controls (Custom Models Only)

LIST OF FIGURES

2.1 EPM Module Dimensions ....................................................................................4

2.2 SMS Module Dimensions ....................................................................................5

3.1 SMS Typical Operating Set Up ...........................................................................9

3.2 EPM Typical Operating Set Up ...........................................................................9

3.2A SMS Remote Programming via Voltage Source ..................................................10

3.2B SMS Remote Programming via External Resistance ...........................................10

3.3 SMS Remote Monitoring .....................................................................................11

3.4A SMS HV ON/OFF Enable (Low) Control ...........................................................11

3.4B SMS HV ON/OFF Enable (Hi) Control ...............................................................12

3.5A EPM Remote Programming via Voltage Source .................................................12

3.5B EPM Remote Programming via External Resistance ..........................................13

3.6 EPM Remote Monitoring .....................................................................................13

3.7A EPM HV ON/OFF Enable (Low) Control ...........................................................14

3.4B SMS HV ON/OFF Enable (Hi) Control ...............................................................14

5.1 Floating Ground Interface Circuit ........................................................................17

LIST OF TABLES

1.1 Options .................................................................................................................2

2.1 Output Voltage and Current ................................................................................6

EPM/SMS MANUAL 1 118026-001 REV K

Chapter 1

INTRODUCTION

1.1 Description Of The EPM/SMS
Series

he EPM/SMS series of high voltage power supplies
provides very well regulated, low ripple high voltage

in a highly efficient, compact design. The
dramatically reduced size of these modules compared to
traditional high voltage modules, is obtained by a state of
the art off-line resonant converter. The resonant converter
utilizes a unique control scheme, which allows constant
frequency operation while maintaining high efficiency.
High operating frequency allows for very low ripple and
excellent dynamic response capabilities.

The DC output voltage and current are controllable over
the full range of operation. Monitoring and control
signals are provided for simple, yet flexible control of the
power supply. The EPM/SMS series operates from
24VAC ±10% or 28Vdc ±10%. (The user should specify
the input voltage at the time of order). The EPM series
operates at 30W continuous and the SMS series operates
at 60W continuous. Neither series requires forced air
cooling. The ambient temperature must be kept below the
maximum rating as specified in 1.2. Consult Spellman
Sales Department for higher power capabilities of the
EPM/SMS series.

The standard warranty applies to the EPM/SMS series
modules. Consult factory about the warranty for custom
modules.

1.2 EPM/SMS Specifications

• Output Control: Voltage and current are externally

programmable over the entire range from zero to

maximum rating via 0-10VDC reference or

potentiometer. (Other scale factors for control and

monitoring can be provided i.e. 1 volt per 10KV, 1

volt per 10mA etc.).

• Input

Voltage: 28Vdc ±10%, 28Vdc ±10% optional.

(Consult the factory for other input
voltages.)

Current: 5A max. on SMS models, 3A max. on

EPM models.

• Voltage Regulation:

Load Regulation: 0.01% of full voltage for a no

load to full load change.

Line Regulation: ±0.01% of full voltage over the

specified input voltage range.

• Current Regulation:

Load Regulation: 0.05% ±25uA from 0 voltage to

full voltage.

Line Regulation: 0.01% of full current over the

specified input voltage range.

• Ripple:

0.1% p-p of output voltage.

• Polarity:

Positive or Negative polarity with respect to ground.
(Specify at time of ordering).

• Stability:

0.01% per hour after 1/2 hour warm up.

• Temperature Coefficient:

100 ppm per C.

• Temperature:

Operating: -20C to -40C
Storage: -40C to +80

• Monitoring:

0 to 10VDC corresponding to 0 to 100% of output
voltage
0 to 10VDC corresponding to 0 to 100% of output
current. (Other scale factors available).

• Control:

Control signal for high voltage enable/disable.

• Environmental:

Indoor use
Altitude up to 2000 meters
80% max. rel. humidity for temperatures up to 31ºC,
decreasing linearly to 50% rel. humidity at 40ºC.
Pollution degree 2 (IEC664)

T

EPM/SMS MANUAL 2 118026-001 REV K

IMPORTANT

This control signal in not a safety

interlock and should not be used for

protection from high voltage generation

for safety purposes.

1.3 Standard Features

The EPM/SMS series incorporates several standard
features designed to optimize user operation.

Slow Start: Provides a gradual increase in high voltage
output until the maximum set point is reached. Various
slow start times can be accommodated. Consult the

Spellman’s Sales Department for information on slow

start options. (The slow start time will be a function of set
point, input voltage and load conditions).

Overvoltage Protection: SMS series only. An
overvoltage protection circuit monitors the output for
excessive voltage generation. Overvoltage conditions can
be caused by an excessive input program signal or an
internal defect in the control circuits. If an overvoltage
condition is detected, the power supply is latched off until
input power is reset.

1.3.1 Remote Operating Features

Remote Programming: Allows remote adjustment of the
output voltage and current via an external voltage source.

Remote Monitor: Allows remote monitoring of the
output voltage and current.

High Voltage Enable/Disable: Allows remote ON/OFF
control of the high voltage.

+10VDC Reference: A +10VDC reference is provided
for remote programming via a potentiometer or resistive
divider.

1.4 Options

The options available are listed in Table 1.1. See section
5 for more information on the options along with
operating and set-up instructions. With few exceptions,
these options can be retrofitted to your power supply at
the factory in a short time. For price and retrofit
arrangements, contact the Spellman Sales Department.

CODE DISCRIPTION

• FG Floating Ground

• 24 24Vdc Input

• NSS No Slow Start

• LL(X) Extra Length Output Cable

• Output Connector

Table 1.1 Options

1.5 Interpreting the Model
Number:

The model number of the power supply describes its
capabilities. After the series name is:

(1) The maximum voltage (in KV).
(2) The polarity of the output – positive (P), negative

(N).

(3) The maximum output (in watts).
(4) The option code for all options that are included.
(5) Custom “X” number representing details listed in

a separate specification control drawing.

EPM/SMS 30 P 60 / FG / X(#)

Series
Name

Voltage

Maximum

Polarity

Option

"X" Number

Custom

Power

Maximum

EPM/SMS MANUAL 3 118026-001 REV K

Chapter 2

Inspection and Installation

nitial inspection and preliminary checkout
procedures are recommended. For safe

operation, please follow the step-by-step
procedures described in Chapter 3, Operating
Instructions.

2.1 Initial Inspection

Inspect the package exterior for evidence of
damage due to handling in transit. Notify the
carrier and Spellman immediately if damage is
evident. Do not destroy or remove any of the
packing material used in a damaged shipment.
After unpacking, inspect the panel and chassis
for visible damage.

Fill out and mail the Warranty Registration card
accompanying the unit. Standard EPM/SMS high
voltage power supplies and components are
covered by warranty. Custom and special order
models (with an X suffix in the model number)
are also covered by warranty.

2.2 Mechanical Installation

The EPM/SMS series module power supplies are
designed for installation into existing or newly
developed OEM equipment. The power supply
can also easily fit into bench top applications or
test set requirements. Standard unit dimensions
are shown in Figure 2.1

For custom mounting requirements or specific

package size requirements consult Spellman’s

Sales Department. Spellman has many package
designs available, or can design a specific
enclosure for your requirements.

The EPM/SMS series utilizes solid
encapsulations for corona free operation. No
periodic maintenance is required. Lower voltage
units (under 6KV) utilize air insulation. Due to
conservative voltage spacing design, periodic
maintenance is not required

I

EPM/SMS MANUAL 4 118026-001 REV K

PIN

FUNCTION

1

Ground

2

+28Vdc

3

High Voltage Enable/Inhibit

4

Voltage Test Point: 10V±2% = 0 to Rated
Output

5

Current Test Point: 10V±2% = 0 to Rated
Output

6

Voltage Programming

7

Current Programming

8

+10.24Vdc Reference

9

Program and Test Point Return

Note: If Enable/Inhibit is not used, connect Pin 3 to Pin 8.

Remote Programming:
Permits remote adjustment of the output voltage

and current via an external voltage source. By
adjusting the voltage source from 0V to 10V the
desired output may be selected.

Remote Monitor:

Test points, pins 4 and 5 of the input connector,
monitor voltage and current outputs. The output
polarity is positive from 0V to 10V equal to 0 to
100% of the output ±0.5%. Output impedance is
1k Ohms.

High Voltage Enable/Inhibit:

Control signal which allows the user to inhibit
the power supply output without switching the
HIGH VOLTAGE OFF. See Figures 3.7A and

3.7B.

Figure 2.1 EPM Module Dimensions

EPM/SMS MANUAL 5 118026-001 REV K

PIN

FUNCTION

1

Ground

2

+28Vdc

3

High Voltage Enable/Inhibit

4

Voltage Test Point: 10V±2% = 0 to Rated
Output

5

Current Test Point: 10V±2% = 0 to Rated
Output

6

Voltage Programming

7

Current Programming

8

+10.24Vdc Reference

9

Program and Test Point Return

10

Not Used

11

Not Used

12

Not Used

Remote Programming:
Permits remote adjustment of the output voltage and

current via an external voltage source. By adjusting the
voltage source from 0V to 10V the desired output may be
selected.

Remote Monitor:

Test points, pins 4 and 5 of the input connector, monitor
voltage and current outputs. The output polarity is
positive from 0V to 10V equal to 0 to 100% of the output
±0.5%. Output impedance is 1k Ohms.

High Voltage Enable/Inhibit:

Control signal which allows the user to inhibit the power
supply output without switching the HIGH VOLTAGE
OFF. See Figures 3.4A and 3.4B.

Figure 2.2 SMS Module Dimensions

EPM/SMS MANUAL 6 118026-001 REV K

2.3 Installation Instructions

The following are installation instructions for the below
listed models. They are approved in accordance with
EN60950:1993/AM1:1993/AM2:1993 and EN61010­1:1993. If installed in information technology equipment,
the installation must comply with the above standard.

• The unit must be fused by an external 5A fuse.

• The unit is convection cooled.

• The maximum permitted temperature of the air

surrounding the power supply is 40ºC.

• The chassis of the power supply should be suitably

connected to Protective Earth.

Model

Output Voltage

Output Power

SMS20X60

20kV/3mA

60W

SMS30X60

30kV/2mA

60W

SMS40X60

40kV/1.5mA

60W

SMS50X60

50kV/1.2mA

60W

SMS60X60

60kV/1mA

60W

Table 2.1

Output Voltage and Current Ratings for

24Vdc or 28Vdc /5A Models

Dieses Geraet ist zugelassen gemaess
EN60950:1993/AM1:1993/AM2:1993 and EN61010­1:1993. Im falle das diesses Geraet in
Informationstechnik-einrichtung eingegaut werden soll,
die installation muss gemaess den obengenannten Norn
erfolgen.

• Das Garaet muss externe fliken Sicherungen

Gesichert sein: 5A

• Kuehlung ohne Luefter.

• Maximale zugelassene Lufttemperature un den

Schaltnetsteil: 40ºC.

• Eine angemessene Verbindung zwischen den

Metallrahmen des Netzteiles und Schutzerde muss
erstellt stein.

Model

Ausgaenge

Output Power

SMS20X60

20kV/3mA

60W

SMS30X60

30kV/2mA

60W

SMS40X60

40kV/1.5mA

60W

SMS50X60

50kV/1.2mA

60W

SMS60X60

60kV/1mA

60W

Table 2.1

Nennwerte

24Vdc oder 28Vdc /5A

EPM/SMS MANUAL 7 118026-001 REV K

Chapter 3

Operating Instructions

3.1 Operation

WARNING

THIS EQUIPMENT GENERATES

DANGEROUS VOLTAGES THAT MAY BE

FATAL. PROPER GROUNDING OF ALL HIGH

VOLTAGE EQUIPMENT IS ESSENTIAL.

IMPORTANT:

Before connecting the power supply to the

AC line, follow this step-by-step procedure.

Do not connect the power supply to the AC

line until Step G is reached.

Failure to follow these procedures may void

the warranty.

A) Insure that the high voltage cable is properly
terminated to the load. Insure that all circuits connected
to the high voltage output are safely interlocked against
accidental contact. Insure external load is discharged.

B) Check the input voltage rating on the serial
nameplate of the supply and make certain that this is the
rating of the available power source. EPM/SMS modules
operate on 28Vdc unless ordered with a different input
voltage option. External fusing is required for the DC
input power. For the EPM/SMS series a 3A type fuse
shall be used. The SMS series uses a 5A fuse.

C) PROPER GROUNDING TECHNIQUE: The
chassis of high voltage power supplies must be grounded,
preferably to a water system ground using copper pipe or
other earth ground. See Figure 3.1 for a typical operating
setup. The return line from the load should be connected
to the power supply chassis. Using a separate external
ground at the load is not recommended.

D) Options Note: See section 5 for hook up and
operating instructions for the options on your unit.
Custom models may also require set up changes.

E) Hook-up: Connect control and monitoring
connections as described in this manual.

F) For initial turn-on, program the voltage and
current for zero output. Connect the enable/disable signal
to disable, open the interlock.

G) The DC input power may now be connected.
H) Enable the power supply via the enable/disable

logic signal.
I) Slowly program the output voltage and current to

desired level. Monitor the output voltage and current via
the monitoring test points. Note equipment operation is
normal, i.e. Load is behaving as predicted.

J) To turn high voltage off, use the enable/disable
signal. If equipment is to be kept off for extended
periods, disconnect power supply from the DC INPUT
source.

Note: (SMS ONLY) If an over voltage condition occurs,
the power supply will latch off. To reset the power
supply, remove the line voltage and reconnect.

WARNING

AFTER TURNOFF, DO NOT HANDLE THE LOAD

UNTIL THE CAPACITANCE HAS BEEN

DISCHARGED!

LOAD CAPACITANCE MAY BE DISCHARGED BY

SHORTING TO GROUND.

WARNING

THE VOLTAGE MONITOR ON THE POWER

SUPPLY FRONT PANEL DOES NOT READ THE

OUTPUT VOLTAGE WHEN THE POWER IS

TURNED OFF, EVEN IF A CHARGE STILL EXISTS

ON THE LOAD.

CAUTION

ALWAYS OPERATE THE UNIT WITH THE COVER

ON. DO NOT ATTEMPT TO ACCESS OR REPAIR

ANY INTERNAL CIRCUITS. DANGEROUS AND

LETHAL VOLTAGES ARE GENERATED INSIDE

THE MODULE.

EPM/SMS MANUAL 8 118026-001 REV K

3.2 Standard Features

A note on remote interface circuitry and remote signal
grounding: whenever possible, electrical isolation should
be provided when interfacing with any high voltage power
supply. For enable/disable signal connections, an isolated
relay or optocoupler should be used. If possible, analog
programming and monitoring signals should be isolated
via analog isolation amplifiers. Spellman application
engineers are available to assist in interface circuitry
design. All interface cables should be properly shielded.
All power supply signals should be referenced to the
power supplies signal ground or power supply chassis
ground

REMOTE PROGRAMMING: Allows remote
adjustment of the output voltage and current via an
external voltage source. A 0 to 10VDC signal is supplied
to Pin 6 of the control input connector for voltage
programming. A 0 to 10 VDC signal is supplied to Pin 7
of the control input connector for current programming.
Programming signals should be referenced to Pin 9 of the
control input connector signal ground. By adjusting the
voltage source from 0 volts (zero output) to 10 volts (full
rated output) the desired output can be selected. See
Figure 3.2A and 3.5B for wiring diagram and
specifications.

An alternate method of controlling the output remotely is
by using external resistance such as a potentiometer or a
resistor network. See Figure 3.2B and 3.5B for wiring
diagram.

Remote Monitoring: Test points are made available for
monitoring the voltage and current output. The test points
are always positive regardless of the output polarity,
where zero (0) to 10 (10) volts equals 0-100% of the
output. See Figure 3.3 and 3.6 for test point wiring.

Enable/Disable Control: Remote control of the high
voltage on and high voltage off can be done via the
enable/disable control. See Figure 3.4 and 3.7 for
recommended interface circuits.

WARNING

It is extremely dangerous to use this

circuit to inhibit high voltage generation

for the purpose of servicing or

approaching any area of load

considered unsafe during normal use.

EPM/SMS MANUAL 9 118026-001 REV K

Figure 3.1 SMS Typical Operating Set Up

Figure 3.2 EPM Typical Operating Set up

EPM/SMS MANUAL 10 118026-001 REV K

Figure 3.2A SMS Remote Programming Via Voltage Source

____________________________________________________________________________________

Figure 3.2B SMS Remote Programming Via External Resistance

EPM/SMS MANUAL 11 118026-001 REV K

Figure 3.3 SMS Remote Monitoring

____________________________________________________________________________________

Figure 3.4A SMS HV ON/OFF Enable (Low) Control

EPM/SMS MANUAL 12 118026-001 REV K

Figure 3.4B SMS HV ON/OFF Enable (Hi) Control

____________________________________________________________________________________

Figure 3.5A EPM Remote Programming Via Voltage Source

EPM/SMS MANUAL 13 118026-001 REV K

Figure 3.5B EPM Remote Programming Via External Resistance

____________________________________________________________________________________

Figure 3.6 EPM Remote Monitoring

EPM/SMS MANUAL 14 118026-001 REV K

Figure 3.7A EPM HV ON/OFF Enable (Low) Control

____________________________________________________________________________________

Figure 3.7B EPM HV ON/OFF Enable (Hi) Control

EPM/SMS MANUAL 15 118026-001 REV K

Chapter 4

PRINCIPLES OF OPERATION

he EPM/SMS Series of high voltage power supplies
utilizes sophisticated power conversion technology.

Advanced analog and power conversion techniques
are used in the EPM/SMS series. The intention of the
Principles of Operation is to introduce the basic function
blocks of the EPM/SMS series power supply. For details
on a specific circuit, consult Spellman’s Engineering
Department.

The EPM/SMS series power supply is basically an DC to
DC power converter. Within the power supply,
conversions of DC to high frequency AC, then to high
voltage DC take place.

Typical EPM/SMS series power supplies comprise a few
basic building blocks. These are: 1) High frequency
quasi-resonant inverter, 2) High voltage transformer and
rectifier circuits, and 3) Control and monitoring circuits.
The following is a brief description of each building
block.

WARNING

The energy levels used and generated by the

power supply can be lethal! Do not attempt to

operate the power supply unless the user has a

sufficient knowledge of the dangers and hazards

of working with high voltage. Do not attempt to

approach or touch any internal or external

circuits or components that are connected or

have been connected to the power supply. Be

certain to discharge any stored energy that may

be present before and after the power supply is

used. Consult IEEE recommended practices for

safety in high voltage testing #510-1983.

4.1 High Frequency Inverter

The EPM/SMS series uses a resonant converter operating
in a zero current switching, resonant flyback and forward
converter topology. MOSFET transistors switch DC
voltage to the resonant circuit. Typical operating
frequency is in the range of 30-35kHz depending on
model. Control of the resonant circuit output is done by

the low voltage control circuits. The resonant circuitry
consists of a resonant inductor and step-up transformer.

4.2 High Voltage Circuits

The high voltage transformer is a step-up type. The
secondary of the high voltage transformer is connected to
the high voltage rectifier circuit. The rectifier circuit will
vary depending upon the rated output voltage. For lower
output voltage, a full bridge or doubler circuit is used.
For higher voltages, a half wave Cockroft-Walton
multiplier is used. A feedback signal is generated by the
high voltage resistor divider. This feedback signal is sent
to control circuits to provide voltage regulation and
monitoring. A current sense resistor is connected at the
low voltage end of the rectifier circuit. The circuit sense
signal is sent to the control circuits to provide current
regulation and monitoring.

In the SMS series, an auxiliary voltage sense signal is
generated by the overvoltage protection feedback resistor.
This is used to provide overvoltage protection.

The high voltage rectifier output is connected to an R-C
type filter to reduce high frequency ripple components.
The filter is then connected to the output limiting resistors.
These resistors limit the peak surge current in the event an
arc or discharge occurring. The limiting resistor output is
connected to the output cable or connector provided.

4.3 Control Circuits

Control circuits are used for regulation, monitoring, pulse­width, control, slow-start and inhibit control. Feedback
signals are calibrated and buffered via general purpose
OP-AMPS. Pulse width control is accomplished by a
typical PWM type control I.C. Logic enable/disable is
provided by a logic gate I.C. Regulators generate +/- 15V
and 10VDC.

4.4 Options

Due to the variations of models and options provided in
the EPM/SMS series, details of actual circuits used may
differ slightly from above descriptions. Consult

Spellman’s Engineering Department for questions

regarding the principles of operations for the EPM/SMS.

T

EPM/SMS MANUAL 16 118026-001 REV K

Chapter 5

OPTIONS

He options available for this power supply are

described in this section. Interface diagrams are

shown where required. Options are specified by
including the option code in the model number as
described in Section 1.4.

5.1 Floating Ground FG

The floating ground option allows isolation of the power
supply common from chassis ground. A typical
application for FG is for connection of an external meter
or circuit into the FG signal point. This circuit can
monitor actual current flow at a low voltage level. See
Figure 5.1 for typical connection to the floating ground
terminal.

IMPORTANT

The power supply common must be

connected to chassis ground through a

low impedance circuit. The power

supply common is clamped to chassis

ground using a power zener diode. This

diode is not intended to clamp under

continuous operation. On higher

current units the power dissipation

within the zener diode can be excessive

if allowed to clamp.

5.2 24Vdc 24

EPM/SMS series power supplies with the 24Vdc input
option will operate from an input voltage of 24Vdc±10%

5.3 No Slow Start NSS

The no slow start option causes the output voltage of the
power supply to rise (within 500 msec) to the rated
voltage upon Power Up.

5.4 Non-Standard Slow Start
SS(x)

The non-standard slow start option allows the gradual rise
time of the output voltage to be different from the
standard of six seconds. To order the option, place the
time desired in seconds after the suffix letter; i.e. SS(10)
denotes a 10 second rise time.

5.5 Extra Length Output Cable
LL(ft)

Standard output cable is 18” long. Other lengths may be
specified.

5.6 Custom Designed Models X(#)

Units built to customer specifications are assigned an X
number be the factory. If this unit is an X model,
specification control sheet is added at the end of this
instruction manual.

Spellman welcomes the opportunity to tailor its units to fit
your requirements or to develop new products for your
applications. Contact the Spellman Sales Department
with your needs.

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EPM/SMS MANUAL 17 118026-001 REV K

Figure 5.1 Floating Ground Interface Circuit

EPM/SMS MANUAL 18 118026-001 REV K

Chapter 6

MAINTENANCE

his section describes periodic servicing and

performance testing procedures.

THIS POWER SUPPLY GENERATES VOLTAGES

THAT ARE DANGEROUS AND MAY BE FATAL.

OBSERVE EXTREME CAUTION WHEN WORKING

WITH HIGH VOLTAGE.

6.1 Periodic Servicing

The EPM/SMS series does not require periodic
maintenance or servicing.

6.2 Performance Test

HIGH VOLTAGE IS DANGEROUS.

ONLY QUALIFIED PERSONNEL SHOULD

PERFORM THESE TESTS.

High voltage test procedures are described in Bulletin
STP-783, Standard Test Procedures for High Voltage
Power Supplies. Copies can be obtained from the
Spellman Customer Service Department. Test equipment,
including an oscilloscope, a high impedance voltmeter,
and a high voltage divider such as the Spellman HVD-100
or HVD-200, is needed for performance tests. All test
components must be rated for operating voltage.

6.3 High Voltage Dividers

High voltage dividers for precise measurements of output
voltage with an accuracy up to 0.1% are available from
Spellman. The HVD-100 is used for voltages up to
100KV. The HVD-200 measures up to 200KV. The
Spellman divider is designed for use with differential
voltmeters or high impedance digital voltmeters. The high
input impedance is ideal for measuring high voltage low
current sources, which would be overloaded by traditional
lower impedance dividers.

T

WARNING

WARNING

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Chapter 7

REPLACEMENT PARTS

7.1 Replacement Parts

Pellman provides parts and assemblies for its high
voltage power supplies but recommends that only

qualified personnel perform the repair. High voltage
is dangerous; even minor mistakes in repairs can have
serious consequences.

When requesting parts please give the model number and
serial number of the power supply.

7.2 Correspondence and

Ordering Spare Parts

Each power supply has an identification label on the rear
of the chassis that bears its model and serial number.
When requesting engineering or applications information,
please state the model and serial number of the power
supply. If specific components or circuit sections are
involved in the inquiry, it is helpful to indicate the
component symbol number(s) shown on the applicable
schematic diagram.

When ordering spare parts, please specify the part’s
description, the part’s reference designation or part

number, and the model and serial number of the unit.

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EPM/SMS MANUAL 20 118026-001 REV K

Chapter 8

FACTORY SERVICE

8.1 Warranty Repairs

During the Warranty period, Spellman will repair all units
free of charge. The Warranty is void if the unit is worked
on by other than Spellman personnel. See the Warranty in
the rear of this manual for more information. Follow the
return procedures described in Section 8.2. The customer
shall pay for shipping to and from Spellman.

8.2 Factory Service Procedures

Spellman has a well-equipped factory repair department.
If a unit is returned to the factory for calibration or repair,
a detailed description of the specific problem should be
attached.

For all units returned for repair, please obtain an
authorization to ship from the Customer Service
Department, either by phone or mail prior to shipping.
When you call, please state the model and serial numbers,
which are on the plate on the rear of the power supply,
and the purchase order number for the repair. A Return
Material Authorization Code Number (RMA Number) is
needed for all returns. This RMA Number should be
marked clearly on the outside of the shipping container.
Packages received without an RMA Number will be
returned to the customer. The Customer shall pay for
shipping to and from Spellman.

A preliminary estimate for repairs will be given by phone
by Customer Service. A purchase order for this amount is
requested upon issuance of the RMA Number. A more
detailed estimate will be made when the power supply is
received at the Spellman Repair Center. In the event that
repair work is extensive, Spellman will call to seek
additional authorization from your company before
completing the repairs.

8.3 Ordering Options and
Modifications

Many of the options listed in Chapter 5 can be retrofitted
into Spellman power supplies by our factory. For prices
and arrangements, contact the Spellman Sales
Department.

8.4 Shipping Instructions

All power supplies returned to Spellman must be sent
shipping prepaid. Pack the units carefully and securely in
a suitable container, preferably in the original container, if
available. The power supply should be surrounded by at
least four inches of shock absorbing material. Please
return all associated materials, i.e. high voltage output
cables, interconnection cables, etc., so that we can
examine and test the entire system.

All correspondence and phone calls should be directed to:
Spellman High Voltage Electronics Corp.

475 Wireless Boulevard
Hauppauge, New York 11788
TEL: [phone] FAX: [phone]
E-Mail: [e-mail]
http://www.spellmanhv.com

To obtain information on Spellman’s product warranty please visit our website at:

http://www.spellmanhv.com/en/About/Warranty.aspx