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New Features
Programmable output current
Improved Reliability
No Neutral with 400VAC input
Revised Front Panel Layout
Voltage/Current Bar Graphs
Optional Local Current Control

• Available in instrumented, and system configurations
• 50kW in DC apps
• 30kJ/sec charge rate
• Compact 7U package
• Current regulated output
• Simple parallel operation for up to 1MJ/sec charge rates

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203 - 20kJ/sec or 30kW DC
HV Systems

APP Note 500: Calculating Capacitor Charge Time
APP Note 502: Calculating AC Line Currents
APP Note 505: Charging units as Continuous Output DC  Supplies
APP Note 507: Charging Large Load Capacitors
APP Note 509: What is Regulation and Repeatability?
APP Note 513: Power Factor Correction
APP Note 517: Protection Against Voltage Reversal
Appn. Questionnaire

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ALE Model 303
Water Cooled High Voltage Capacitor Charging and DC Power Suplies
Output Voltages: 0-1kV to 0-50kV at 30kJ/sec average power or 50kW DC
Click here to request more ALE 303 Information

  • Overview
  • Technical Details
  • Technical Support

Product Overview and Models

The 303 Series is a Compact (7U high) water-cooled rack mount constant current capacitor charging or DC power supply with output voltages available from 0-1kV to 0-50kV, 400VAC*, or 480VAC three phase input, with fully instrumented front panel (L model), or optional Slave version.


  Capacitor Charging Ratings   Continuous DC Ratings    
Model Number Output

Cap Charging

Cap Charging



DC Power

DC Current (Amps)



303L-1kV-POS 0-1,000   30,000 37,500 75   50,000 50  
303L-2kV-POS 0-2,000   30,000 37,500 37.5   50,000 25  
303L-4kV-POS 0-4,000   30,000 37,500 18.75   50,000 12.5  
303L-5kV-POS 0-5,000   30,000 37,500 15   50,000 10  
303L-10kV-POS 0-10,000   30,000 37,500 7.5   50,000 5  
303L-15kV-POS 0-15,000   30,000 37,500 5   50,000 3.3  
303L-20kV-POS 0-20,000   30,000 37,500 3.75   50,000 2.5  
303L-30kV-POS 0-30,000   30,000 37,500 2.5   50,000 1.65  
303L-40kV-POS 0-40,000   30,000 37,500 1.87   50,000 1.25  
303L-50kV-POS 0-50,000   30,000 37,500 1.5   50,000 1  
Other Voltage Available on Request, please contact factory for details.
* Note: 50kW average DC power rating with 480VAC input, derate to 40kW with 400VAC input.


Ordering Information





  Input Voltage  

Factory Options


L - 15kV - POS - 3P480 for 480VAC - 5V
  S           3P400 for 400VAC   LP

The new and improved 303 series capacitor charging supplies are one of the highest power units available in a single package. The advanced water cooled design allows an average capacitor charging power of 30kJ/sec (or 50kW continuous DC) to be realized from a 12.25" high supply. Multiple product upgrades have resulted in improved reliability and added product features, such as optional current programming, constant power mode for charging large load capacitors, and a current bar graph for models with the slave front panel.

The 203 uses an advanced fluid based cooling technique. The coolant is an inert fluorinated hydrocarbon (non CFC) fluid which is a liquid at room temperature but boils at a relatively low 59°C. All of the high power and high voltage electronics in the supply are immersed in the coolant which serves both to cool and insulate the components. As a component heats up, the coolant in contact with it vaporizes and it is this liquid to vapor phase transition which efficiently removes the excess heat from the components. The coolant vapor is cooled by a heat exchanger located in the area above the fluid. This cooling technique allows very high power electronics to operate continuously and reliably in a very small volume.

For more information about the 303 Power Supply Series, contact the TDK-Lambda Americas Programmable and High Voltage team directly at +1-732-795-4100 or online at -

A wide range of other TDK-Lambda Programmable and High Voltage power supplies can be viewed from the website:


AC Input
Input Voltage (VAC) Current 
340-460, 47-63Hz, 3ph 68A
432-528, 47-63Hz, 3ph 53A

Average Charging Rate
30,0000 J/s at rated Output Voltage.
*25,000 J/s with 400VAC input.
Note that average charge rate is specified for repetition rates to a maximum of 200Hz. For operation above 200Hz the peak charge rate may be reduced.

Peak Charging Rate
37,500 J/s at rated Output Voltage.
*32,500 J/s with 400VAC input.
Note that peak charge rate is specified for repetition rates to a maximum of 200Hz. For operation above 200Hz the peak charge rate may be reduced.

Average Continuous DC Power
50,000 Watts at rated Output Voltage.
*40,000 W with 400VAC input.

Standard Voltage Ranges
1, 2, 4, 5, 10, 15, 20, 30, 40, 50kV.
All models continuously variable from 10 to 100% of rated voltage output.
Linear to within 1% of full scale.
Accuracy 1% of rated.

Available as fixed Positive or Negative, Please Specify.

High Voltage Assembly
Sealed fluorinated hydrocarbon insulated and cooled.

Voltage Medium Output Cable
PFS Fluid DS2214
30-50kV PFS Fluid DS2212


Input Connector
VDE, UL, CSA, approved.

AC Line Contactor
VDE, UL, CSA, approved line contactor.

Power Factor
Passive PFC 0.9 min.

Better than 85%.

Stored Energy
Less than 0.3 Joules all models.

0.2% per hour after 1 hour warm-up.

Flowed water at 2US GPM (7.6L/min) exit temperature between 15°C and 35°C. All water paths are at ground potential and are stainless steel, or copper.

Pulse to Pulse Repeatability
+/- 2% to 100Hz standard. For higher repetition rates, consult factory.

Temperature Coefficient
100 PPM per °C

Ambient Temperature
Storage: -40 to +80 °C
Operating: 5 to +45 °C

10-90% Non-condensing.

The power supply is protected against open circuits, short circuits, overloads and arcs.


19" rack (483mm) x 22"(560mm) x 12.25"(311mm)
Weight 220lbs (100kg)
Rack mountable with General Devices
CTS-122 or CTS-222 or equivalent slides with 3.875" hole centers

Click here for mechanical details

Shipping Details:
Wooden skid (freight shipment only): 32"(0.81m)x26"(0.66m)x29"(0.74m)
Weight: 305lbs, 140kg

Accessories (included with unit)
1-29kV Models - 10ft long, DS2214 coaxial cable with proprietary connector design.
30-50kV Models - 10ft long, DS2212 coaxial cable with proprietary connector design.
Operating manual.

Remote Control
Via 25pin d-type connector on rear panel. Click here for details


Suffix-5V 0 to +5V programming = 0 to full scale output voltage (standard 0-10V)
Suffix-LP Latching Overload Protection.
Supply will latch off, requiring a reset if an overload condition occurs.
Suffix-DC Continuous DC Operation
Suffix-LCA Constant power mode for charging large load capacitors
Suffix-RS Remote load voltage sense input for external 1000:1 or 10,000:1 precision HV divider.
Suffix-CP 10 turn Current Programming pot and/or 0-10V remote input for DC units only
All specifications subject to change without notice.
Factory Technical Support Contacts

High Voltage Products - 1000V and higher
All ALE models, 500A, 102A, 152A, 202A, 402, 802, LC1202, 203, 303, HV Systems
PHV and FLX-HV High Voltage DC Models
Support Hours 8am-5pm Eastern
Standard Time
Andy Tydeman - Email
Tel: (732) 795 4149
Fax: (732) 455 6026
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