ElmoMC SimplIQ Analog Servo Amplifiers-Ocarina Installation - Manual (Page 23)

Chapter 4: Servo Control Operation
4.1 Current Command Input
The Ocarina and Castanet have a single differential input. The input operating voltage
range is ± 3.75 V, meaning that a 3.75 V signal will result in a fully rated peak current. The
current limit circuits will override this signal if the peak duration exceeds 2.7 seconds
and/or the required current exceeds the values set by the ECLC and ECLP signals. If the
input command voltage exceeds 3.75 V, input scaling must be implemented by adding a
pair of external resistors, according to the following formula:
Rin (kΩ) = (5.33 * Vin) - 20
Be careful not to apply input voltage above the maximum allowed input voltage as this
will cause the input operational amplifier to operate beyond its limits (±20 V) and in
extreme cases, may even damage it.
4.2 External Current Limit - Continuous (ECLC)
The continuous current limit of the Ocarina and Castanet amplifiers can be scaled down by
an external voltage or by an external resistor connected from pin J1/9 (ECLC) to pin J1/8
(ECLRET).
4.2.1 External Voltage
An external positive voltage (0 to 3.75 V) to terminal J1/9 (ECLC) in reference to terminal
J1/8 (ECLRET) will control the continuous current limit from zero to Ic (nom).
The voltage is internally clamped to 3.75 V whenever the external VECLC is greater than
3.75V.
The external voltage source must be able to source/ sink at least ±0.2 mA.
The maximum absolute VECLC allowed to be connected is 5 V.
Ocarina/Castanet Installation Guide 4-1
MAN-OCSIG (Ver. 1.4)
V
ECLC
IC(new) =
3.75V
* Ic(nom)
V
ECLC
IC(new) =
3.75V
* Ic(nom)