MULTICHANNEL SIGNAL CONDITIONER MODEL 482C GENERAL OPERATION MANUAL
4
Model 482C05 System Description
The Model 482C05 is a basic four channel signal conditioning unit designed to interface measurement signals to readout
or recording devices.
The following are features that come standard on every 482C05:
Unity gain
Input fault and overload LED’s
Variable ICP
source current, 0 to 20 mA
Lighted power indicator on the front panel
Rear panel BNC input/output connectors
1-4.5.
Model 482C05 ICP
®
Input/Output Mode
The Model 482C05 contains a regulated 26 VDC power supply that provides constant current for up to 4 individual
channels. Both the output and input connections utilize BNC connectors and are brought out through the rear panel. The
unit is AC coupled only. The 482C series offers optional DC Coupling. Consult factory
1-4.6.
Adjusting the Current Source
The Current adjustment is located on the rear of the unit. Use a standard small flat screwdriver to adjust the “I ADJ”
potentiometer. Turning the adjustment slot clockwise will increase the current, while counterclockwise will decrease the
current. Do this adjustment only while a DC mA meter or DMM set to mA is connected to any “ICP” BNC. One
adjustment controls all channels. The unit is factory set to 4mA and can be adjusted between 0mA-20mA.
1-4.7.
Fault Indications
The three red LED’s on the front panel are all indicators of some type of problem. The normal good operation state is
when all fault lights are off. The “OPEN” light indicates that the Bias voltage is over that of most sensors and is close to
an open circuit voltage of 26VDC. The photo on the cover is shown with the unit on, and no sensors attached, so the
“OPEN” LED is on. The “SHORT” light indicates a very low Bias voltage close to 0VDC. The “OVERLOAD” light
indicates a signal level of +/-10V Peak has been detected and the signal may be in danger of clipping. These fault lights
are active for all channels, at the same time.
1-5.
Installation
Both the Model 482C15 and the Model 482C05 come packaged in a standard box and require very little in term of
installation. The box should be located in such a way as to allow convenient access to the power outlet for disconnect
purposes. Since these units have low power consumption, they can be located in confined environments.
NOTE:
Specific installation is available; contact PCB
1-6.
Grounding Techniques
Integrating either of these Models into an application that links the outputs to other test equipment powered by line
voltages may lead to errors or loss of signal-to-noise ratio due to ground loops. The evidence of ground loops is easily
seen whenever the fundamental frequency (50 or 60 Hz) or a multiple of the fundamental frequency is present in the
system when the sensors are “at rest.” In order to maintain the operating specification of noise and reduce the effects of
line interference, proper grounding techniques should be used. The following procedure may be helpful:
1. Make sure the signal ground lines of all equipment are tied together. The signal grounds of the channels are typically
tied together via the case of the input and output BNC connectors. The individual channels of the Model 482C15 and
482C05 have their signal ground line tied together internally at the power supply.
