Hello, I want to reduce 12 volts to 7 volts, how many ohms do I need using a resistor?

[johansasa]

Hello, I want to reduce 12 volts to 7 volts, how many ohms do I need using a resistor?

 

[danadak]

How much current do you need ? Does the load vary in current draw ?
What is accuracy of 7V you need ? What is range of 12V input ?
What is 7V load ? A motor, bulb, radio.....?


These are all specifications you need to do a proper design.

 

[bertus]

Hello,

Is it a fixed load, or can it vary like an amplifier.
You can use a voltage regulator to have a steady voltage.

Bertus

 

[Delta Prime]

Using only one resistor in series with your load, that is your load must be used as the other resistance in order to divide the voltage by the ratio of the ohmic value of the now two resistors.
You wish to make a voltage divider, that takes two resistors. Your load must be purely resistive & your 12 volt source must
not change, meaning no batteries.

 

[Bluejets]

Hello, I want to reduce 12 volts to 7 volts, how many ohms do I need using a resistor?

Save youself a lot of bother and use a $2 buck ( down) converter.

 

[AnalogKid]

This question is so blazingly incompetent, it smells like a troll.

ak

 

[Delta Prime]

This question is so blazingly incompetent

Well.... Maybe that's why, it makes sense to me,

 

[Delta Prime]

@johansasa
Is this another sensor for audible, visual, alarm?
For your hearing impaired brother?
Would your brother happen to have a Binaural Cochlear Implant hearing prosthetic? If so we can use that to our advantage for targeting the prosthetics audible frequency sensitivity
With a audible alarm within that frequency sensitivity range of the prosthetic.

 

[AnalogKid]

Hello, I want to reduce 12 volts to 7 volts, how many ohms do I need using a resistor?

3.

 

[johansasa]

I connect a resistor to both sides, but no current flows. If I remove the resistor it gets current. Why is this happening?

I connected a 3 ohm resistor, the current does not go away, if I remove it, it goes away. This is the power unit.

My purpose is not to ask troll questions, but to reduce the voltage of the power unit. I could not achieve 7 volts. Its value does not change. When I connect a resistor, it cuts off.
It's not worth it for something like this, a 7 volt one is on sale, I'll buy it from there, but thank you very much anyway.

 

[danadak]

Post #2 has a number of pertinent questions.....

 

[crutschow]

You seem to have a minimal understanding of circuits, and don't answer our questions, so how can we answer yours?

 

[davenn]

The OP isnt answering questions asked to help them

Thread closed
@johansasa if you want the thread reopened, message me and show me that you are ready to answer the Q's that have been asked of you