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Calculate the impedence of your 3V circuit in ohms. Figure the voltage you want to drop. In this case, you need to lose 9V. This is three times the voltage you are supplying, so the resistor should have three times the resistence of your 3V circuit. If your circuit has 100 ohms of resistence (impedence), then you would connect a 300 ohm resistor in series with your circuit.
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How do you convert 12 volts dc to 3 volts dc for LED?
Depends on the led forward bias threashold, if its a typical led it will be .7 volts so, .7x6=4.2V, so pick a resistor that will drop around 7 volts. What is the current? Then just to V=IR, 7=IR.
Can a device requiring 12 volts and 3 amps run with an adapter providing 12 volts and 2 amps?
No. Your power supply must be able to supply rated voltage (12 volts) and rated current (3 amps).
Can you convert a 3 phase air compressor to 240 volts?
only way to convert from 3 phase to 240 would be to change the electric motor on the compressor
A 12 volt circut with two 3 ohm resistors in parallel will draw how much current?
Two 3-ohm resistors in parallel have an effective resistance of 1.5 ohms.I = E/R = 12/1.5 = 8 AmperesNote: Use big resistors. The power dissipated by each resistor is E2/R = 48 watts !
Do you convert 12-3 equals 9?
The answer depends on what you wish to convert it to. One possibility is 12-9 = 3
How much current flows through a circuit if the if the resistance is 4 ohms and there is a 12-volt battery?
When two 4-ohm resistors are connected in parallel across 12 volts:-- Each resistor has 12V across it, so the current is I = E/R = 12/4 = 3 amperes.-- The total current from the battery is 6 amperes.-- The effective resistance as seen by the battery is R = E/I = 12/6 = 2 ohms.-- If you didn't know the voltage of the battery, you would calculate theeffective resistance of the parallel resistors in advance like this:1/R = 1/4 + 1/4 = 1/2R = 2 ohms.When you connected them to a battery, the battery would agree.
What is the difference between a 9v 300mA Adapter and a 12v 300mA Adapter?
difference is 2.7 amperes in numbers will be 12 volts 3 amps and the other will be 12 volts .3 amps
What is the voltage of a battery that supplies a current of 42 A across 3 resistors who each have a resistance of 4 ohms?
There is insufficient information in the question to properly answer it.You need to specify if the resistors were in series or parallel.Also, it is incorrect to say "current ... across" - it must be "current ... through".Assuming that you mean a series circuit then it can be solved:R(total) = Sum of the resistors in seriesR(tot) = 3 x 4 Ohm= 12 OhmOhm's Law:V = IRV = 42 x 12= 504 Volts(Note: Because Ohm, Volt and Ampere were named after scientists they are always given capital letters. Ohm not ohm)
What is the current in a circuit with 9 volts 3 ohms 2 ohms and 4 ohms?
The current in the circuit will depend on how the three resistors are wired. Series? Parallel? Series parallel? With the resistors in series, 3, 2 and 4 ohms will add to 9 ohms. As I = E/R, I = 9 V / 9 ohms = 1 A. With the resistors in parallel, the 3, 2 and 4 ohm resistors will draw 3 A, 4.5 A and 2.25 A respectively, and the total current will be the sum of the branch currents, or 3 A + 4.5 A + 2.25 A = 9.75 A. There are 3 different series parallel circuits possible, and more investigation will be necessary to solve for them.
How do you wire 3 batteries to get 24 volts?
Connect three 12 volt batteries in series. You will triple the amperage but the volts will remain at 12. Click the link
How to convert 440 VOLTS to 380 VOLTS?
3 phase 220 volt submersible motor convert to 440 volt
If 3 resistors of 56 12 and 33 ohms are in parallel what is there combined resistance?
The combined resistance is 7.6049 ohms.
