What type of resistor to simulate a typical 12V turn signal bulb? What I’m trying to do is I have a relay connected to what should be a turn signal bulb wire. The relay obviously has a lower resistance than the light bulb that should be there so now I have a relay doing that “hyper blinking” crap. I know some people think that’s cool but I want it to blink normal. So what type of resistor should I put in parallel with the relay?

 

p=v^2/r like speakers

So a 35 watt blinking indicator has 4.11 ohms resistance.

 

well if it's in parallel you will also need to know the impedence of the coil in the relay. A typical Bosch relay is 75 ohm. you will also need to put a diode in parallel with the coil of the relay cathode on the positive terminal of the coil. Measure it then use
R=(-(impedence of coil)*V^2)/(V^2-p*(impendence of coil))

If you are wondering what the diode does does it discharges the inductor when the relay shuts off other wise you are going to send approx 200 volts back down the wire.

With vtegs 35 watt bulb you would need a 6.5 ohm resistor.
With this circuit the relay would disipate 2.76 watts and the resistor would need to disapate 32 watts. I don't know of any 32 watt resistors other than light bulbs. Maybe explain a little more what you are trying to do and why you need a relay, there may be a more elegent way to do what you are trying to do. It may take me a while to respond I am putting a clutch in my car.


Otherwise you would need to put 32 208 ohm 1 watt resistor in parallel.


Modified by nsxxtreme at 1:25 AM 6/18/2003