2007-08-19 16:02:17 · 3 answers · asked by Ronald A 1 in Science & Mathematics ➔ Engineering
Your equipment will draw whatever current it needs.
Voltage divided by resistance = current (i.e. amperes)
If your equipment draws 20 mA, then it has an approximate internal resistance of 13.8 V ÷ 0.020 A = 690 Ω.
2007-08-19 16:13:38 · answer #1 · answered by Thomas C 6 · 1⤊ 1⤋
Ronald ...i'm undecided if i'm answering the main appropriate question right here ...cutting-edge is a function of utilization so any regulated furnish able to providing 20ma will do. Now in case you desire to apply the voltage provided as a calibrator then we are able to pass someplace. the suitable calibration equipment interior the international purely makes use of a pair of discreet aspects in spite of if the version is they examine it against a super style of comprehend values...diploma the resistance in a small 12v easy bulb we could say a GE1157 (its an automobile taillight) you will discover out the Resistance is approximately 6ohms in one filament and 8ohms in the different...and with that expertise we are able to are anticipating the present which would be 2 amps at 12vdc. Now because of the fact that we used a lamp we could see that it become lit examine bodily the parameters it become working decrease than and are anticipating wit accuracy an out come. SOOOOO...in case you desire to try this for a 20ma load get a %. of resisters (blended values) or a variable and set the voltage low...low...low... and examine out some . in case you have a 0-100ma indicator (multimeter) examine your values. as quickly as you have wide-unfold a series resistance then you definately can use the small resistor examined and you reg/potential furnish for a calibrator...in spite of if in the journey that your utilising this to calibrate an Oscilloscope extra advantageous use the in-built calibrator....and additionally each so often I purely use a stable Ole a million.5vdc dry cellular battery..they final alongside time and while they pass you toss em...hiya in the previous i'm getting out of right here seek for electronics regulator experiments on the internet there is international of stuff obtainable...Even a number of my stuff....stable success from the E....
2016-12-12 07:07:31 · answer #2 · answered by Anonymous · 0⤊ 0⤋
One transistor and one variable resistor.
Connect the 13.8Vdc to the collector of the transistor. Connect the variable resistor between the Base and Collect of the transistor, and get your current output from the emitter.
2007-08-20 13:50:16 · answer #3 · answered by ngcolin 2 · 0⤊ 0⤋