Who knows their electricity?

[my95tsi]

I need a 20-40ohm 12watt resisitor for wiring into my 2nd o2 sensor to remove the cel. Could i use a 50ohm 20watt resistor instead? Would it hurt to use something alittle bigger?

 

[Bostedquest]

I need a 20-40ohm 12watt resisitor for wiring into my 2nd o2 sensor to remove the cel. Could i use a 50ohm 20watt resistor instead? Would it hurt to use something alittle bigger?

It would probly be OK, but try to get something a little closer. Typically once you go over 10% things can take unexpected turns.
I owuld honestly use the smallest resistance one you can get away with. That way if something else feeds off that pulse, it can still get its signal.

 

[my95tsi]

well i know it does have a resistance of +/- 10% Is that any better?

 

[Defiant]

http://vfaq.com/mods/O2bypass.html

 

[my95tsi]

Thanks bvut i've seen that page about a hundred times. Thats not what i'm working with. I have an o2 simulator and since the heater cxircuit is not working the company told me to solder a 20-40ohm resistor in between the two heater wires. But all i can get ahold of is a 50ohm resistor.

 

[CyberEye]

hrmm I can't even find my electronics kit from school, i'd probably have some.

 

[napkinthief]

Thanks bvut i've seen that page about a hundred times. Thats not what i'm working with. I have an o2 simulator and since the heater cxircuit is not working the company told me to solder a 20-40ohm resistor in between the two heater wires. But all i can get ahold of is a 50ohm resistor.

any electronic store should have resistors for sale...

 

[my95tsi]

Not radio shack. They only have really small resistors, nothing that wil fit my application.

 

[Catbox_95]

If you wire resistors in Series, they add their ohm rating. So, if you can find some 10 ohm resistors, wire them in a series to increase ohms. Three 10 ohm resistors in a series will give you 30 ohms.

That's what I did.

 

[my95tsi]

Wait i'm confused. I heard that the higher the ohm the less resistance, which is bad for what i want. I guess 50ohm is bad. Two 50 ohm resistor wired in parallel makes 25ohm is that because they are in parallel? and not back to back?

 

[Catbox_95]

Wait i'm confused. I heard that the higher the ohm the less resistance, which is bad for what i want. I guess 50ohm is bad. Two 50 ohm resistor wired in parallel makes 25ohm is that because they are in parallel? and not back to back?

Yes. Parallel halfs it, Serial doubles it.

 

[my95tsi]

So if the application asks for 12ohm will using a higher ohm reisitor such as 50ohm be worse than using a lower one such as 10 ohm?

 

[ADrewzki]

Worse is really a vague term. The wires that you're going to solder the resistor to will have a certain amount of voltage running through them. If you increase the resistance, current will drop and vice versa.

V=IR (V=Voltage, I=current, R=resistance)
As R increases, I will decrease if there's a constant regulated voltage supplied.

However, as you increase or lower current, your resistor that you soldered in there will heat up differently.

P=IV (P=power, I=current, V=voltage).
Your voltage is constant regulated, current goes up because of the small resistor you put in there, so heat goes up.

If you really need a 12Ohm resistor, you can find a few smaller resistors to wire up together in series (one after another) or you can find a 20ohm and 30ohm resistor and wire them up in parallel. That will give you 12 as well. Good luck!

 

[mastadogg2]

For the 2 Black wires on the sensor would it hurt if i had them swapped around, cause i had my harness cut and had to reconnect the wires, and im not positive if i got the 2 black wires on the right ones since there both black.

 

[Quasimondo]

www.digikey.com

12W 20-40 ohms you say?

Hunington Electric vitreous wirewound power resistor
FVTS10(insert resistor value here)-ND
2.78/ea, 2.38/per 25

Resistor values
20, 25, & 30 ohms

Ohmite vitreous enamel power resistor
B12J(see code below)-ND
2.46/ea, 2.21/per 25

Resistor Codes
20 ohms - 20R
25 ohms - 25R
35 ohms - 35R


Both resistors are rated at 12 watts

 

[ThEstablishment]

If you already have 50ohm resistors, wire 2 in parallel, which will give you 25ohms. Google resisters in parallel if you don't know what to hook where.