Hi, I had a question if you guys could help, I want to convert the cars 12V source to 5 or 6Vs to power a small DC motor. What size resistor should i use? (OHMS)
Thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skt &raquo;</TD></TR><TR><TD CLASS="quote">Hi, I had a question if you guys could help, I want to convert the cars 12V source to 5 or 6Vs to power a small DC motor. What size resistor should i use? (OHMS)
Thanks </TD></TR></TABLE>

That would depend on how much power the motor draws, also remember with the ignition off the voltage will be around 12, with it on it will be around 14.4

You might want to look around and see if you can't find a 5 or 6 volt voltage regulator, this way it won't matter if the voltage is 12 or 14.4, the regulator will "bleed off the extra".

 

What kind of regular would I get? Also are those cheap as resistors (99cents)

something like this?

http://www.radioshack.com/prod...-1770

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skt &raquo;</TD></TR><TR><TD CLASS="quote">What kind of regular would I get? Also are those cheap as resistors (99cents)

something like this?

http://www.radioshack.com/prod...-1770</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rjr162 &raquo;</TD></TR><TR><TD CLASS="quote">

That would depend on how much power the motor draws, also remember with the ignition off the voltage will be around 12, with it on it will be around 14.4

You might want to look around and see if you can't find a 5 or 6 volt voltage regulator, this way it won't matter if the voltage is 12 or 14.4, the regulator will "bleed off the extra".</TD></TR></TABLE>

A voltage regulator will cost more then $.99 $5 for a cheep one, you need more then just a resistor, take the motor to a elec. supply store like Radio Shack, tell them what you want to do, they will tell you what you need to do it. 94

 

PS why not use a 12v motor? 94

 

The motor is 12V, Its spinning ot fast for me, I want to slow it down with a 5V source of power now..

 

T think you can do that with a dimmer control. 94

 

Do not use a resistor. If you do the voltage will change depending on the load.

If you want to be able to adjust the voltage use an adjustable voltage regulator. It would also be wise to figure out your worst case load this will help you determine if you need a heatsink.


Modified by nsxxtreme at 2:04 PM 11/7/2004

 

hmm, So I should use a voltage regulator, the Small 12V DC motor uses the car's battery which is about 14 when the car is up and running and way to much for that little motor! I need about 4-6V's going through it. The little motor probably has 1 or 2 watts going through it. Its like an RC car motor.

 

Use a set off batteries to add up to 4 volts. Then use a DMM so you can measure the current it is using while it is connected to whatever it is that you are using it for. You can use an adjustable voltage regulator to obtain any voltage you want.

 

Ok, I got some ratings off the small 12V DC motor im using:

Gearhead Motor
60 RPM, 12VDC @ 110mA

This spins to fats when I plug it straight up to my cars 12V power supply. I want it to spin slower, I tried hooking it up to a 6V battery and it did spin incredibily slow, which is what I wanted. So how would I get this motor to spin to the speed of 4 or 5Vs?

 

Use an adjustable voltage regulator if you want to be able to adjust the speed at which the motor turns. If not just buy a 5 volt regulator and be done with it. Both parts can be purchased at radio shack. If you download the datasheet it will tell you how it needs to be connected

The purpose of measuring current is just to determine if you will need a heat sink.
Good luck