LT 2100 400Pot Control Models: LT-252-400-4, LT-270-400, LT-2100-400

Voltage Control Models: LT-253-400, LT-253A-400, LT-273-400, LT-2103-400

These converters transform an unregulated 115 VAC 400 Hz to a regulated and adjustable DC output via a remote control potentiometer or voltage for voltage controlled models.   

The LT-2XX-400 Series is a pulse width-modulated AC to DC converter that provides regulated DC power output. The LT-2XX-400 Series is primarily designed to control the light intensity of incandescent bulbs in vehicle  lighting systems. For special orders any two combinations of LT-52A, LT-53, LT-70, LT-73, LT-100 and LT-103 dimmer units may be configured in a single box.


  • State of the art design for regulation and positive logic for output overvoltage protection.
  • Other LT-2XX-400 Series available in various output voltage and power ratings in the same package, or special units can be provided for various output combinations.
  • A panel mount trim pot is provided for the voltage control series to control 0-5 VDC output via 0-3 to 0-5 VDC.
  • A test jack is provided to monitor output voltage.
  • Designed to meet various applicable portions MIL-STD 704 notice 3, MIL-STD-202 and MIL-T-5422F class 1A.
  • The Model LT-2XX-400 Series is serviceable, small and lightweight (42 watts per pound and 1.7 watts per cubic inch)
Input Voltage: 115 VAC ± 10% @ 400 Hz.
Output Voltage: Adjustable with external 5K ohm, 1/2W rheostat or voltage 0-3 VDC to 0-5 VDC.
Regulation: 2% for line, 2% load and 2% temperature.
Output Ripple: 25 mVp-p or less.
Protection (Overload): Input and output currents pulse when overload exceeds approximately 125% of rating.
Protection (Overvoltage): Output voltage is limited to approximately 125% of rating eventhough remote control rheostat opens or internal failure occurs.
Temperature: -55°C to +71°C (sufficient cooling required @ +71°C ambient)
Altitude: 55,000 Feet.
Size: 6.5" L x 6.7" W x 2.4" H.
16.5 cm L x 17 cm W x 6 cm H
Weight: 3.6 lbs. (1634 grams).


LT-2XX-400 SERIES LT-252-400-4
Max. Power Rating (watts) 100 150 200 75
Input Voltage (VAC) @ 400 HZ 105-125 105-125 105-125 105-125
Input Current (ARMS) @ FL @ 115 VAC 1.6 2.0 2.8 1.2
Output Voltages DC two parallel 0 to 5 0 to 12 0 to 28 0 to 5
Output Current (ADC) Total 0-20 0-12 0-7 0-15


A 115 VAC 400Hz AC input 105 VAC to 125VAC
B 400Hz AC input Ret. Isolated
C Output control 0-5K Pot or 0-3 VDC to 0-5 VDC *
D, E DC Output Two output in Parallel Operation
F, G DC Return Chassis Ground
J2 Output Voltage Test Point  

* Control range by a panel mount Trim Pot.

AC to DC Power Supplies