Elmo ISP manual Converting the amplifier into current mode, Selecting the reference signal gain

36

7.1.2Velocity mode

To operate in velocity mode the velocity loop should be enabled by converting the error amplifier to a high gain PI amplifier.

Make sure that: R6 (30ohm), R5 (475Kohm) and C1 (0.022 æF), in solderless terminals, are installed on the board.

7.1.3Current mode

a) Converting the amplifier into current mode

To operate in current mode the velocity loop should be disabled by converting the error amplifier to a low gain proportional amplifier.

-Remove R6 (in solderless terminals).

-Remove C1 (in solderless terminals).

In addition, you must make sure that the velocity feedback signal is not entering the error amplifier. If a tachogenerator is used, make sure that it is not connected to the amplifier.

b) Selecting the reference signal gain

The ISP has 2 single ended inputs (terminals H-1,R-32a,E-J1/3 and H-5,R-28a,E- J1/1) and a differential input (terminals H-3,R-30a,E-J1/4, and H-4,R-30c,E-

J1/5).

The standard procedure recommends to use the differential input for the

reference signal.

Following are the input maximum voltage and impedance with the standard values

of input resistors:

INPUT - RESISTOR				STANDARD	MAX.	Current Gain(A/V)	INPUT
				VALUE	VOLTAGE	(in current mode)	IMPEDANCE
Input	1	-	R1	2.49Kohm	11V	0.46xIc	17.5 Kohm
Input	2	-	R2	15Kohm	19V	0.27xIc	30Kohm
Differential - R3,4				20Kohm	30V	0.27xIc	30 Kohm

See chapter 4.1 for calculation of other values

ISP - Rev 6/95