# Convert 12V DC to 6V DC

ezrollin
Copper - Posts: 65
Joined: August 22, 2008
Location: Texas, United States
Posted: August 22, 2008 at 7:14 PM / IP Logged

I hook negative voltage meter to negative battery post.

I hook resistors to battery positive then voltage meter positive to the last resistor.

I hear you saying that resistors dont resist voltage but resist Current (amps) instead.  I just dont understand why and how you came up with the 6v using 2 resistors (when it resists current instead of voltage)?   thanks again!!

megaman
Copper - Posts: 385
Joined: June 24, 2008
Location: Montana, United States
Posted: August 22, 2008 at 7:38 PM / IP Logged

first of all your diagram shows the voltmeter in series with the circuit.  This means that you have almost no understand of basic electronic principles.  Please do not attempt to build a circuit.  No need to get all huffed up about not knowing basic electronics, I have no idea how to make a cake and that is pretty simple.. so I'm told.

Here's your proper voltage divider diagram which WILL NOT WORK in your scenario as it doesn't supply the necessary current for your application, and for a host of other reasons.

ezrollin
Copper - Posts: 65
Joined: August 22, 2008
Location: Texas, United States
Posted: August 22, 2008 at 8:01 PM / IP Logged

wow, are you an electrician or an artist?  very nice!

thanks alot!

i am an idiot
Platinum - Posts: 13,566
Joined: September 21, 2006
Location: Louisiana, United States
Posted: August 22, 2008 at 8:41 PM / IP Logged
ezrollin wrote:
 I hook negative voltage meter to negative battery post.I hook resistors to battery positive then voltage meter positive to the last resistor.   I hear you saying that resistors dont resist voltage but resist Current (amps) instead.  I just dont understand why and how you came up with the 6v using 2 resistors (when it resists current instead of voltage)?   thanks again!!

If you connect the above circuit, the meter will read 12 volts.  The reason for this is there is no current going through the circuit.  The input impedance of your meter is phenominally high.  The resistors will drop voltage, but it is dependent on current.  No current draw, no voltage drop.

The reason you can use a resistor to drop voltage for an LED or a light bulb, (things that do not vary in current draw) is that they pull a given amount of current, you can adjust the value of the resistor to get the appropriate amount of voltage drop, to power the lamp or LED. The reason you can not use a resistor to drop voltage on a pump (or anything electromechanical) is that when it is not under a load, it will not pull as much current as it does when under a load.  So when you need the pump most, it will not be getting enough voltage to operate.

ezrollin
Copper - Posts: 65
Joined: August 22, 2008
Location: Texas, United States
Posted: August 22, 2008 at 9:35 PM / IP Logged

thanks alot guys!  very informative!  It looks like I'm dumber than I thought.

you can keep the info coming if you want!

Looks like I have no other choice but to buy the voltage regulator (which is fine, would love to have several)

On my motorcycle my key lock cylinder has failed.  When I turn my key to run I get NO lights whatsoever.   12v goes into my key lock cylinder and when the correct key is inserted the key lock cylinder is supposed to spit out 6v DC which goes to my computer (to allow it to run).

I'm trying to bypass my key lock cylinder.

I have no problems posting the title to my bike or whatever you want.

Much appreciated!

i am an idiot
Platinum - Posts: 13,566
Joined: September 21, 2006
Location: Louisiana, United States
Posted: August 22, 2008 at 9:53 PM / IP Logged

What kind of bike is this?   I have heard of the same Hocus Pocus on a GSXR, but several are for sale on the internet with Remote start units installed.  I found a diagram of the GSXR and there is nothing of the sort on the bike.  They say the ECU is looking for 9 volts on that bike, according to the diagram, the ignition switch provides a ground for the ECU  the Magic Regulator is inline with the power wire of the ECU.

i am an idiot
Platinum - Posts: 13,566
Joined: September 21, 2006
Location: Louisiana, United States
Posted: August 22, 2008 at 10:02 PM / IP Logged

I still have no idea what kind of Bike you have,  here is the diagram for the GSXR   Ignition switch is in center of page at top.   ECU is at top all the way to the right.  This bike too is supposed to have some magic in the key.  Notice the right side of the ignition switch simply connects the orange wire from the ECU to ground.  The ECU may only run on 9 volts as they say, but if it does, the regulation is in the power side of the unit.  The orange wire is simply looking for ground to allow it to turn on.

ezrollin
Copper - Posts: 65
Joined: August 22, 2008
Location: Texas, United States
Posted: August 22, 2008 at 10:05 PM / IP Logged

sorry about that delay

Its a 2001 Kawasaki Ninja 750 P model (carbs)

clean & clear title

Paid \$3500 from some sort of lawyer guy in dallas

ezrollin
Copper - Posts: 65
Joined: August 22, 2008
Location: Texas, United States
Posted: August 22, 2008 at 10:14 PM / IP Logged

That has no load... it would get really hot and might explode the battery.  Am I remotely correct?

i am an idiot
Platinum - Posts: 13,566
Joined: September 21, 2006
Location: Louisiana, United States
Posted: August 22, 2008 at 10:28 PM / IP Logged
Not gonna blow up or heat up as long as the resistors are 1 watt or larger. The circuit will need to handle 3/4 of a watt.
OHM'S LAW
BASE FORMULAS      P=I*E      E=I*R
TO FIND VOLTAGE      E=P/I      E=I*R      E=SQR(P*R)
TO FIND CURRENT      I=P/E      I=E/R      I=SQR(P/R)
TO FIND POWER      P=I*E      P=E2/R      P=I2*R
TO FIND RESISTANCE      R=E2/P      R=E/I      R=P/I2
P = Power in Watts
E = Electromotive Force in Volts
I = Electrical Current in Amps
R = Electrical Resistance in Ohms
SQR = Square Root
Note:
I use 'E' to represent voltage most of the time but sometimes you'll see 'V' used for voltage. Don't let it confuse you.
Copied and Pasted with permission form BCAE1.com
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