| Author |
Message |
John or Han
Guest
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 Posted:
Tue Feb 15, 2005 6:11 am Post subject:
What type of resistor do I need? |
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I'm upgrading the tail lamps on my vehicle and one set of bulbs are not
being used in the new configuration. However, these two bulbs were monitored
by the vehicle's bulb failure system.
I'd like to exchange the bulbs with two resistors (to trick the Bulb Failure
Module), but I'm not sure what kind to use.
They are 5 Watt bulbs.
Thanks
-John
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Wing Fong Wong
Guest
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| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
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neverunwired@aol.com <johnandhan@verizon.net> wrote:
| Quote: | Also...
I tried a 10K Ohm, 1/2W, 5% resistor just for kicks...didn't work either.
Would a lower Ohm rating be necessary? For 1/2W resistors they also have:
680, 560, 330, 150, and 100 Ohms.
-John
Could it be that the detection system in your car is more sofisticated |
than you think. A bulb's resistance does change as it heats up therefore
the current will change also. You might try some nichrome(sp?) resistance
wire and winding your own resistor instead. This might seem more *bulb*
like to the car.
--
Wing Wong.
Webpage: http://wing.ucc.asn.au |
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Henry Kolesnik
Guest
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| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
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P=E*E/R therefor R=E*E/5=13*13/5=33 ohms so use something between 33 and
40 ohms, 5watts. It might be easier to get some sockets and bulbs and use
them as the resistor making it easier to replace on burn out. 5 watts is a
lot of energy to dissipate so make sure in either case you don't melt
something or start a fire.
--
73
Hank WD5JFR
"John or Han" <johnandhan@verizon.net> wrote in message
news:fsbQd.21177$uc.13297@trnddc02...
| Quote: | I'm upgrading the tail lamps on my vehicle and one set of bulbs are not
being used in the new configuration. However, these two bulbs were
monitored by the vehicle's bulb failure system.
I'd like to exchange the bulbs with two resistors (to trick the Bulb
Failure Module), but I'm not sure what kind to use.
They are 5 Watt bulbs.
Thanks
-John
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neverunwired@aol.com
Guest
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| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
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Yes...these bulbs are not used on the newer taillamp cluster...they are
auxilary/duplicate.
<William P.N. Smith> wrote in message
news:fqj211lnncg7iluiv1bqfp11qbopu8ntsb@4ax.com...
| Quote: | "John or Han" <johnandhan@verizon.net> wrote:
I'm upgrading the tail lamps on my vehicle and one set of bulbs are not
being used in the new configuration.
Can you do that and still be DOT legal?
|
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neverunwired@aol.com
Guest
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| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
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Henry,
I appreciate your help. I'm sort of at the halfway point of understanding
simple circuits and using component parts (correctly).
To possibly clarify something...I know that on the vehicle, the 55W fog
lights (optional), if not fitted, were replaced with a 1000 ohm (don't know
the wattage rating, etc.) resistor to override the bulb failure system. I'm
trying to apply the same concept, but I don't know the appropriately rating
of resistor needed for a 5W bulb. Obviously I need just enough current
bridged to make the module think a bulb is in place.
Don't know if that tells you how 'sensitive' the BFM is or if it makes any
difference. Like I said, not very educated in this area, just pick a little
up along the way.
And where would I locate a resistor of the appropriate rating? Thanks!
-John G.
P.S. Trying to keep the system clean and efficient. Would like to avoid
having the circuit extended w/ a couple of bulbs just burning w/ no real
purpose (other than keeping the BFM happy).
"Henry Kolesnik" <kolesnik@sbcglobal.net> wrote in message
news:jJbQd.47176$iC4.29834@newssvr30.news.prodigy.com...
| Quote: | P=E*E/R therefor R=E*E/5=13*13/5=33 ohms so use something between 33 and
40 ohms, 5watts. It might be easier to get some sockets and bulbs and use
them as the resistor making it easier to replace on burn out. 5 watts is
a lot of energy to dissipate so make sure in either case you don't melt
something or start a fire.
--
73
Hank WD5JFR
"John or Han" <johnandhan@verizon.net> wrote in message
news:fsbQd.21177$uc.13297@trnddc02...
I'm upgrading the tail lamps on my vehicle and one set of bulbs are not
being used in the new configuration. However, these two bulbs were
monitored by the vehicle's bulb failure system.
I'd like to exchange the bulbs with two resistors (to trick the Bulb
Failure Module), but I'm not sure what kind to use.
They are 5 Watt bulbs.
Thanks
-John
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Guest
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| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
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"John or Han" <johnandhan@verizon.net> wrote:
| Quote: | I'm upgrading the tail lamps on my vehicle and one set of bulbs are not
being used in the new configuration.
|
Can you do that and still be DOT legal? |
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Anthony Fremont
Guest
|
| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
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"neverunwired@aol.com" <johnandhan@verizon.net> wrote in message
news:vWcQd.31157$uc.13334@trnddc03...
| Quote: | Henry,
I appreciate your help. I'm sort of at the halfway point of
understanding
simple circuits and using component parts (correctly).
To possibly clarify something...I know that on the vehicle, the 55W
fog
lights (optional), if not fitted, were replaced with a 1000 ohm (don't
know
the wattage rating, etc.) resistor to override the bulb failure
system. I'm
trying to apply the same concept, but I don't know the appropriately
rating
of resistor needed for a 5W bulb. Obviously I need just enough current
bridged to make the module think a bulb is in place.
|
This is good information to know. It means that the high-side switch
being used in your vehicle is only looking for a path to ground to
determine if "a bulb is good". As opposed to looking for a low
resistance path to ground. The easiest thing for you to do is to try a
1K resistor and see if it works. At 13.8V (more realistic than 12V), a
1K resistor will dissipate <1/4W, but it's getting a bit close when you
allow a 10% tollerance on the resistor. You may wish to use a 1/2W to
be extra safe.
| Quote: | Don't know if that tells you how 'sensitive' the BFM is or if it makes
any
difference. Like I said, not very educated in this area, just pick a
little
up along the way.
And where would I locate a resistor of the appropriate rating? Thanks!
|
One paragraph and one question above. ;-)
| Quote: | -John G.
P.S. Trying to keep the system clean and efficient. Would like to
avoid
having the circuit extended w/ a couple of bulbs just burning w/ no
real
purpose (other than keeping the BFM happy). |
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neverunwired@aol.com
Guest
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| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
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Anthony,
I agree that I think the 1K Ohm resistor 'should' work. I picked up a small
pack from Radio Shack this afternoon and tried them before hoping on here.
They are 1K Ohm, 1/2 Watt, with 5% Tolerance. My guess is maybe the
tolerance is the issue? (If I'm not mistaken, 5% current is allowed
through?) So then maybe 10% would be more appropriate? Thanks.
John
"Anthony Fremont" <spam@anywhere.com> wrote in message
news:f8dQd.58216$sr1.31072@fe2.texas.rr.com...
| Quote: |
"neverunwired@aol.com" <johnandhan@verizon.net> wrote in message
news:vWcQd.31157$uc.13334@trnddc03...
Henry,
I appreciate your help. I'm sort of at the halfway point of
understanding
simple circuits and using component parts (correctly).
To possibly clarify something...I know that on the vehicle, the 55W
fog
lights (optional), if not fitted, were replaced with a 1000 ohm (don't
know
the wattage rating, etc.) resistor to override the bulb failure
system. I'm
trying to apply the same concept, but I don't know the appropriately
rating
of resistor needed for a 5W bulb. Obviously I need just enough current
bridged to make the module think a bulb is in place.
This is good information to know. It means that the high-side switch
being used in your vehicle is only looking for a path to ground to
determine if "a bulb is good". As opposed to looking for a low
resistance path to ground. The easiest thing for you to do is to try a
1K resistor and see if it works. At 13.8V (more realistic than 12V), a
1K resistor will dissipate <1/4W, but it's getting a bit close when you
allow a 10% tollerance on the resistor. You may wish to use a 1/2W to
be extra safe.
Don't know if that tells you how 'sensitive' the BFM is or if it makes
any
difference. Like I said, not very educated in this area, just pick a
little
up along the way.
And where would I locate a resistor of the appropriate rating? Thanks!
One paragraph and one question above. ;-)
-John G.
P.S. Trying to keep the system clean and efficient. Would like to
avoid
having the circuit extended w/ a couple of bulbs just burning w/ no
real
purpose (other than keeping the BFM happy).
|
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Anthony Fremont
Guest
|
| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
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"neverunwired@aol.com" <johnandhan@verizon.net> wrote in message
news:cldQd.32971$Dc.7267@trnddc06...
| Quote: | Anthony,
I agree that I think the 1K Ohm resistor 'should' work. I picked up a
small
pack from Radio Shack this afternoon and tried them before hoping on
here.
They are 1K Ohm, 1/2 Watt, with 5% Tolerance. My guess is maybe the
tolerance is the issue? (If I'm not mistaken, 5% current is allowed
through?) So then maybe 10% would be more appropriate? Thanks.
|
5% is better accuracy than 10%. This all means that your resistors may
actually measure anywhere from 950 Ohms to 1050 Ohms. A 10% tolerance
resistor would measure out at somewhere between 900-1100 Ohms.
The 1/2W is the important issue for you so things don't get too hot.
So, didn't they work for you? |
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neverunwired@aol.com
Guest
|
| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
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|
Assuming it doesn't matter which direction the resistor is pointing...NO,
I'm afraid it didn't. What would be the next step?
-John
"Anthony Fremont" <spam@anywhere.com> wrote in message
news:otdQd.58330$sr1.31756@fe2.texas.rr.com...
| Quote: |
"neverunwired@aol.com" <johnandhan@verizon.net> wrote in message
news:cldQd.32971$Dc.7267@trnddc06...
Anthony,
I agree that I think the 1K Ohm resistor 'should' work. I picked up a
small
pack from Radio Shack this afternoon and tried them before hoping on
here.
They are 1K Ohm, 1/2 Watt, with 5% Tolerance. My guess is maybe the
tolerance is the issue? (If I'm not mistaken, 5% current is allowed
through?) So then maybe 10% would be more appropriate? Thanks.
5% is better accuracy than 10%. This all means that your resistors may
actually measure anywhere from 950 Ohms to 1050 Ohms. A 10% tolerance
resistor would measure out at somewhere between 900-1100 Ohms.
The 1/2W is the important issue for you so things don't get too hot.
So, didn't they work for you?
|
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| Back to top |
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neverunwired@aol.com
Guest
|
| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
|
|
Also...
I tried a 10K Ohm, 1/2W, 5% resistor just for kicks...didn't work either.
Would a lower Ohm rating be necessary? For 1/2W resistors they also have:
680, 560, 330, 150, and 100 Ohms.
-John
"Anthony Fremont" <spam@anywhere.com> wrote in message
news:otdQd.58330$sr1.31756@fe2.texas.rr.com...
| Quote: |
"neverunwired@aol.com" <johnandhan@verizon.net> wrote in message
news:cldQd.32971$Dc.7267@trnddc06...
Anthony,
I agree that I think the 1K Ohm resistor 'should' work. I picked up a
small
pack from Radio Shack this afternoon and tried them before hoping on
here.
They are 1K Ohm, 1/2 Watt, with 5% Tolerance. My guess is maybe the
tolerance is the issue? (If I'm not mistaken, 5% current is allowed
through?) So then maybe 10% would be more appropriate? Thanks.
5% is better accuracy than 10%. This all means that your resistors may
actually measure anywhere from 950 Ohms to 1050 Ohms. A 10% tolerance
resistor would measure out at somewhere between 900-1100 Ohms.
The 1/2W is the important issue for you so things don't get too hot.
So, didn't they work for you?
|
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| Back to top |
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Rich Webb
Guest
|
| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
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|
On Tue, 15 Feb 2005 03:06:53 GMT, "neverunwired@aol.com"
<johnandhan@verizon.net> wrote:
| Quote: | Also...
I tried a 10K Ohm, 1/2W, 5% resistor just for kicks...didn't work either.
Would a lower Ohm rating be necessary? For 1/2W resistors they also have:
680, 560, 330, 150, and 100 Ohms.
|
If you need to match the current draw then you'll need smaller, larger
resistors. Smaller resistance (to match the load) and a larger power
rating (so that the magic smoke doesn't get out ;-)
The original 5 W bulbs would have been something like a 40 Ohm load.
Hop back over to Radio Shack and pick up a couple of their 50 Ohm 10 W
resistors (SKU 271-133) and see if that does the trick.
--
Rich Webb Norfolk, VA |
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Anthony Fremont
Guest
|
| Posted:
Tue Feb 15, 2005 6:11 am Post subject:
Re: What type of resistor do I need? |
|
|
"neverunwired@aol.com" <johnandhan@verizon.net> wrote in message
news:hHdQd.18773$uc.3031@trnddc05...
| Quote: | Also...
I tried a 10K Ohm, 1/2W, 5% resistor just for kicks...didn't work
either.
Would a lower Ohm rating be necessary? For 1/2W resistors they also
have:
680, 560, 330, 150, and 100 Ohms.
|
A 500 Ohm resistor would dissipate about .38W, so you need to keep that
in mind. Any smaller on the resistor value and you really need to look
at a 1W resistor or larger. |
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mc
Guest
|
| Posted:
Tue Feb 15, 2005 8:42 am Post subject:
Re: What type of resistor do I need? |
|
|
"neverunwired@aol.com" <johnandhan@verizon.net> wrote in message
news:vWcQd.31157$uc.13334@trnddc03...
| Quote: | Henry,
I appreciate your help. I'm sort of at the halfway point of understanding
simple circuits and using component parts (correctly).
To possibly clarify something...I know that on the vehicle, the 55W fog
lights (optional), if not fitted, were replaced with a 1000 ohm (don't
know the wattage rating, etc.) resistor to override the bulb failure
system. I'm trying to apply the same concept, but I don't know the
appropriately rating of resistor needed for a 5W bulb. Obviously I need
just enough current bridged to make the module think a bulb is in place.
|
OK, that's much easier. I had rather suspected that it would be satisfied
with much less current (more resistance) than a real bulb.
Presumably there are 12 volts across it. The required wattage (minimum) is
therefore 144/R, where R is resistance in ohms.
What I'd do is go to Radio Shack and buy some 1000-ohm 1/4-watt resistors.
Try one of them. If that doesn't work, try two in parallel. Or four in
parallel... or Radio Shack's 50-ohm 10-watt resistor. Bear in mind that a
resistor that is dissipating a high wattage gets hot. |
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mc
Guest
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| Posted:
Tue Feb 15, 2005 9:54 am Post subject:
Re: What type of resistor do I need? |
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Try a lower resistance.
Also, look up "Ohm's Law." It's the fundamental principle of electrical
current and you're really handicapped by being unaware of it at this point. |
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