Spam-n-Rice ETR

Since the load is supposed to see an equivalent resistance of 10 ohms and the LED "bulb" and the additional load resistance is to be connected in parallel, the equation to use is:

10 = (R1*R2)/(R1+R2)

Solving for R2....

R2 = 1/(1/10-1/R1)

where...

R1 = the equivalent resistance of the LED "bulb" = Voltage at the bulb leads/current going through the bulb

R2 = "additional load resistance"

RVTS4

Then take it out of the circuit and measure that value with the multimeter...then go buy that value of resister and use it in the circuit...Remember that if you have to use multiple ones, add then in series NOT parallel..
That's what i would do...the other way is tedious and measuring the impedance of an LED is pointless.

RVTS4

To measure current you have to put the meter in series with the LED...then you would have to measure the voltage drop across the LED with another meter...use the variable Pot like I said to..go to radio shack and get a 1 K ohm and a 500 ohm pot...remember to use two terminals close to eachother...which two do not matter...connect it into the circuit and slowly turn the pot till you get the blink speed you want. Oh..I do have a masters from John Hopkins...

audimods

Exact frequency of blinks was not my goal. that rough 10ohms will get him very close to the stock blinking frequency. plus i rounded somewhere too.

audimods

that potentiomenter/resistor better be rated for 20w. you won't find that readily.

Spam-n-Rice ETR

Just remember to get a resistor that can handle the current...

Spam-n-Rice ETR

true....mouser.com has some 25W power resistors.

Spam-n-Rice ETR

ditto.

audimods

mouser, digikey, partsexpress, newark, I'm always looking for others.

RVTS4

The max power would be V^2/R...where R is the resistance, V would be the drop across the resister and it at max it would be less than 12 volts. Sounds like a fun little experiment.