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If you are referring to the 4-20 mA analog scale signal, I think it has to do with the fact that these currents cause a 1-5 voltage to result across a 250 Ohm resistor in series with the current. (V=IR, 1=0.004*250 and 5=0.020*250) 5v was a popular voltage for logic devices historically.
What else can I help you with?
Why 4-20 ma is used in Analog Signals?
Earlier, instead of 4-20 mA, 0-100 mA was used. But the usage of 0-100 mA led to sufficient power dissipation. Hence the upper range was reduced to 20 mA to optimize the power dissipation (this was found by experiments). In this way the upper limit was set. But this 20 mA is limited to cable length of 50 meters. For the lower limit i.e. 4mA . Zero was not used as the lower limit because it give no intimation about actual zero value or zero transmission due to some breaks in the circuitry. Therefore 4mA was set as the lower limit as it is also above the maximum leakage current in electronic circuits. In some transmitters, some times the transmitter shows 2 mA. This is used to indicate that there is some fault in the sensor. Actual zero is indicated by 4 mA. The scale is linear. For example, in a pressure transmitter of range 400bar. 0 bar - 4 mA 100 bar - 8 mA 200 bar - 12 mA 300 bar - 16 mA 400 bar - 20 mA. The reason for not using voltage is that voltage continuously drops over the length of the wire whereas current can be transmitted over a given length without any drop. The main purpose of using electrical quantities is transmission to remote locations.
What value of current in a 1W - 20V zener diode must be limited to a maximum?
ANSWER A reverse biased 20 V zener clamps the voltage across its terminals to 20 V. Since 50 mA x 20 V = 1 W, the current through the diode should be limited to a maximum of 50 mA. In practice, this current maximum would be derated for reliability reasons.
Standred voltage used for transmission of 4-20 ma signals?
4ma = 1v rising to 5v @ 20ma
What is the percent signal corresponding to an 11.3 mA signal?
To calculate the percent signal from a given current, you typically need a reference value, often the maximum current for a 100% signal. Assuming a common reference maximum of 20 mA (used in many industrial applications), you can calculate the percent signal as follows: [ \text{Percent Signal} = \left( \frac{11.3 , \text{mA}}{20 , \text{mA}} \right) \times 100 = 56.5% ] Thus, an 11.3 mA signal corresponds to approximately 56.5%.
Why is 4-20 mA used more often in analog signaling and not 0-20 mA?
The 4-20 ma is used more often in analog signaling than 0-20 ma because sufficient power dissipation. The hence is the upper rage and was reduced to 20 ma.
4-20 ma loop testing?
Yes a 4 - 20 ma loop can be tested.
Can you use a 1300mA universal adapter for a 200mA device?
Yes, the maximum that the adapter can deliver is 1300 mA or 1.3 amps. The maximum that the device will draw is 200 mA or .2 of an amp.
What is a 4-20 ma is it a dry contact?
A 4-20 mA signal is an analog current loop commonly used in industrial automation to transmit sensor measurements over long distances. It represents the range of the measurement, where 4 mA typically indicates the lowest value and 20 mA the highest. This type of signal is not a dry contact; instead, it requires a powered loop and can provide continuous data transmission. Dry contacts refer to a switch that does not directly supply power, often used for simple on/off signals.
What is Bcbs of ma filing limit for billing?
90 days from the dos
Can 9v 1000ma adapter work with a 9v 700ma device?
Yes, the rating of the adapter is the maximum amount of current allowed to be drawn from it. The adapter you state has a maximum of 1000 mA or 1 amp. If the device draws 700 mA's you will have 300 mA's of spare capacity.
How many miles per gallon does a 2001 Nissan Maxi ma get with 100 thousand miles?
city = maximum 20 miles per gal highway = 26 miles per gal
When did Ma Ji die?
Ma Ji died on 2006-12-20.
