BARGRAPH
|
|||||||||||||||||||
|
|||||||||||
|
|
|||||||||||
|
|||||||||||
|
|
|||||||||||
| BARGRAPH DESCRIPTION
The AM-20 BARGRAPH is a highly versatile, solid-state analog meter capable of a variety of user programmable display modes. It is designed to meet the requirement in many applications for a rugged, high input impedance meter that has instantaneous response and is immune to the vibration, sticking and overshoot problems associated with needle-type meters. The meter's display consists of 20 LED segments individually driven by 20 comparators divided into a left side set and a right side set of ten comparators each. The user can select and adjust the three internal reference voltages that are applied respectively, to the left side of the left comparator set, the center point where the two comparator sets are joined in series and the right side of the right comparator set. The meter's circuitry detects when the input signal corresponds to the voltage at any one of the 20 points along the two comparator divider networks with a step accuracy of better than 0.1%. The meter can be adjusted so that both comparator sets have an equal reference voltage across them which will produce a linear full scale display, or if required, they can have a different reference voltage which will enable each half of the meter's display to have a different scale or sensitivity. The user may program the meter for either a "bargraph" or "dot" mode of display. In the "bargraph" mode, each segment is turned on when its individual comparator voltage is less or equal to the input signal. In the dot mode the only segment turned on is the one with its individual comparator voltage most equal to the input signal. When a varying input signal is applied to the meter, the "bargraph" mode gives the visual effect of increasing and decreasing column or bar of lighted segments whereas, in the "dot" mode, the single lighted segment gives the appearance of a moving dot. Another feature of the AM-20 BARGRAPH is the capability to increase the between segment resolution by use of the Proportional Brightness Dot mode. This display mode functions in the same manner as the dot mode except that instead of a single lighted segment it provides an adjustable band of three or more lighted segments with their proportionate brightness accurately indicating the exact relationship of the input signal between any two segments. The real versatility of the AM-20 BARGRAPH lies in its many easily programmable display formats. The dot mode, for example, offers a unipolar left-to-right, or right-to-left, or bipolar center zero left and right motion. In the bar mode, user programming can achieve a unipolar left-to-right motion, a unipolar center zero expanding bar motion, or a unipolar center full scale intersecting bar motion. When using the dot mode, the user may program the meter to turn on the 5th, 10th, 15th, and 20th segments at half brightness to serve as scale indicators. The AM-20 BARGRAPH also offers two forms of overrange indication which can be enabled by the user. In the dot mode, the 10th and 20th segments will flash. In the bar mode, the 11th through 20th bars will flash. The meter may also be operated in either mode without the flashing overrange. Signal input ranges are user programmable from 400mV to 1200V full scale. Provision has also been made for an offset voltage capability which permits the meter to be operated as a 4 to 20mA transducer receiver, or to provide special scaling in most any required engineering unit. For special applications, two or more meters may be cascaded in the bar mode to provide an even greater resolution. SPECIFICATIONS Input Configuration: …… Single-ended Full Scale Ranges: …… 2VDC (Standard) 20VDC 200VDC 1200VDC (Maximum Input Signal) All ranges except 1200VDC are field adjustable from 20% to 120% of the basic full scale range value. Signal Input: ...... signal for accurate measurement. The Amplitude of AC signals in the audio frequency range can also be directly measured. Input Impedance: ...... Exceeds 20M ohms on 2V range; 10M ohms on all other ranges. Input Protection: ...... 200VDC or 150VAC maximum on 2V ranges; 1200VDC or 850VAC on all other ranges Normal Mode Rejection: ...... 30dB at 50Hz and up Accuracy: …… ±0.5% of Full Scale Maximum Resolution: ...... Over 2% in proportional brightness dot mode. Temperature Coefficient: ...... 150PPM/ degree C on 2V range; 200PPM/ degree C on all other ranges Zero Stability: ……20µV/ degree C Typical Conversion Rate: ……Instantaneous Flash Converter Display: ……0.15" Segment height; 20 LED's Polarity: ……Operates with positive signal inputs only; negative signals are clamped by 100K ohms and a diode. Bipolar signals can only be measured when the input signal is isolated from the power supply of the meter. Overload Indication: ……If an input signal exceeds full scale on any range when the bargraph mode is used, the 11th to 20th segment will flash approximately 2 times per second. In the dot mode only the 10th and 20th segments will flash. Scale Indication: ……The 5th 10th, and 20th display segments may be turned on at half brightness to indicate scale. *Power Requirements: ……+4V to +24VDC at 20mA in dot mode, +4V to +6VDC at 180mA in bar mode; Caution: The bar mode cannot be used for supply voltages greater than +6VDC due to the limited heat dissipation capabilities of the display drive ICs. Warm-up Time: ……Instantly to specified accuracy Operating Temperature: ……-10 degree C to +60 degree C ORDERING INFORMATION STANDARD AM-20 PANEL METER (2V RANGES) ……AM-20 ACCESSORIES: Edge Connector (20 pin solder tabs) ……CN-L10 OPTIONS: …… Factory Installed 20V Range …… VF-0020V Factory Installed 200V Range ……VF-0200V Factory Installed 1200V Range …… VF-1200V Factory Installed Special Scaling: Due to the ease of field adjustability and wide versatility of the AM-20 factory installed scaling is unnecessary. For large volume orders, the AM-20 can be factory prescaled and calibrated on a contract basis. RANGE CHANGE KITS: (matched resistors for user installation) 20V Range ……VK-0020V 200V Range …… VK-0200V 1200V Range …… VK-1200V OPTIONAL CASES: (see back page for details) End Mount Case (for twin mounting) ……EM-CASERED Center Mount Case (for multiple array mounting) ……CM-CASERED Slim Bezel Case (supplied as standard) ……SL-CASERED For ordering information call: 1-800 TEXMATE (1-800-839-6283) |
|||||||||||
