Electrical engineers....need help with LED turn signal lights..........
#11
I'd like to add...
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"
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"
#12
Re: use a variable resister to adjust it while in the circuit fo ther speed you want it to blink..
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.
That's what i would do...the other way is tedious and measuring the impedance of an LED is pointless.
#13
Re: That will not work...unless you have 2 meters..
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...
#14
you're right. I didn't account for that.
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.
#20
Re: true enough...do this....
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.