SGA AC/DC Powered Signal Conditioner

Connector Pin Diagram

The Strain Gage Amplifier SGA

Available in two versions, the SGA for 110/230V AC or 18-24V DC operation and the SGA-D which is DC powered only.

Cabling

Power Connection

Two power supply options are available:

SGA:

• 220/230VAC, 50/60Hz
• 110/120VAC, 50/60Hz
• 5W Max

SGA & SGA-D:

• 18-24V DC, 5W (approx. 150mA fully loaded)

NOTE: The SGA can be powered from AC or DC sources whichever is available. It is also possible to connect BOTH AC and DC simultaneously for security of power supply.

Power Connection

Standard mains 2 or 3 core cable PVC sheathed (unshielded) cable will suffice for the power.

NOTE: Connect the appropriate power to the SGA. For AC powering observe the correct transformer jumper connections as shown in the Power Connection above. (This diagram is also provided inside the lid).

DCI Module Connections

To accommodate automotive installations, the SGA can be fitted with an DCI module enabling it to be powered from 9 to 36V DC.

This module also has the advantage of electrically isolating the DC power supply from the measurement electronics which minimizes errors and instability due to earth loops in the system.

The power supply should be capable of supplying at least 1A for 12V installations and 0.5A for 24V.

Connections to the SGA & SGA-D input/output signal and the power supply are made via 2.5mm² field terminal connectors.

Cable entry in the cased versions is via glands in the ends of the case.

Input (Sensor) Connections

NOTE: Strain Excite is the Excitation to the transducer. Strain Input is the Signal from the transducer. The Ref 5V/2.5V is generated internally and used for calibration.

The cable connecting the sensor to the SGA should be shielded.

This typical cable data is provided for information only.

The cable should have 2 x twin twisted cables. Ideally with each pair individually shielded and with an overall shield.

Output Connections

Two analog outputs are available from the SGA, proportional DC current and DC voltage. The ranges available are as follows: –

The DC current support both ‘sink’ and ‘source’ modes of operation.

Two jumpers JP1 & JP2 provide the means of selecting the desired mode.

Output Connections

In ‘Sink’ mode the positive end of the load is connected to the internal +15V supply on the SGA and the negative end is connected to the SGA output. The current through the load is ‘sunk’ by the SGA towards ground (0V).
N.B. In this mode neither connection to the output load is electrically common to the load cell.

For more information visit Electrical Wiring Diagrams