Detailed Product Description

DESCRIPTIONOF TRIGERRING CARDS:

Libratherm offers SCR triggering cards model LTC-12,LTC-13 and LTC-15, which are designed to fire or trigger back to back connected SCRs using synchronized phase angle control technique. The card accepts analogue control signals of (0 5)VDC or (4 20)mA and provides proportional gate/cathode triggering pulses G1K1 + G2K2.  These pulses can be used to trigger back-to-back connected SCRs of as high as 500Amperes.  The card also provides built in regulated5VDC supply to connect external potentiometer to manually control the SCR firing. The on card ramp up and ramp down settings allows gradual rise and fall of the voltage output across the load. 

LTC-12and LTC-13 are same in all respect, except the card LTC-13 accepts the feedback signal from the external current transformer for the current limit and trip features. This feature is useful for transformers load or inductive loads or heating loads like Silicone Carbide and Molybdenum, which exhibits significant changes of resistance with increase in temperature. This feature will restrict the load current to the value set using the on card current limit(CL) potentiometer. On sudden increase in the current the current trip feature will over ride over the current trip feature and the firing of the thyristor will stop instantly. The trip contacts are available on the terminals.

These cards can be used for heating control applications to control the AC power to the heating coils or to the transformer or for DC rectifiers. Three such card scan be used for both 4-wire STAR and 6-wire DELTA configurations of the load.

Three Phase SCR triggering card model LTC-15is used to fire three pairs of back to back connected SCRs configured as three phase 4 wire star with neutral or 6 wire open delta.

FEATURES:

• Can easily fire15 Amps to 500 Amps SCR modules.

• Single phase / 2phase / 3 phase versions.

• Suitable for 4wire star with neutral / open delta 6 wire configuration.

• Suitable for single phase or three phase DC rectifiers.

• Auto / Manual operation.

• Accepts (4-20)mA/ (0-5)VDC / (0-10)VDC control input.

• Soft start for smooth control.

• Adjustable power and current limit.

• Ideally suitable for resistive, transformer, inductive or heating loads like Silicone Carbide and Molybdenum which exhibits significant changes of resistance with increase in temperature.