Basic question (I think)

[T Hakemack]

I'm wanting to replace a soleniod in a seat belt system with a resistor. The
soleniod has 56 ohms resistance, 12 volts dc, and draws .237 amps.

Can I put a 56 ohm 3 watt resistor in its place or am I totally out in left
field?

TIA Tom

 

[Mr Fixit]

The load is the same but why are you doing it?

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perhaps he has a death wish

 

[Sam Goldwasser]

I'm wanting to replace a soleniod in a seat belt system with a resistor. The
soleniod has 56 ohms resistance, 12 volts dc, and draws .237 amps.

Can I put a 56 ohm 3 watt resistor in its place or am I totally out in left
field?

The load is the same but why are you doing it?

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.

 

[Set Square]

In an earlier contribution to this discussion,

I'm wanting to replace a soleniod in a seat belt system with a
resistor. The soleniod has 56 ohms resistance, 12 volts dc, and draws
.237 amps.

[That would actually require 13.27 volts into 56 ohms]

Can I put a 56 ohm 3 watt resistor in its place or am I totally out
in left
field?

Power = V^2 / R - so a 56 ohm resistor across 12v will dissipate 144/56 =
2.57 watts.

However, if it's going in a car, it will be running at 14v or more when the
alternator is charging - and 14^2 / 56 = 3.5 watts - so 3 could be a bit
marginal.

 

[T Hakemack]

Thanks, I chose a 5 watt just to be safe. Glad I did, didn't think about the
actual voltage.

In an earlier contribution to this discussion,

I'm wanting to replace a soleniod in a seat belt system with a
resistor. The soleniod has 56 ohms resistance, 12 volts dc, and draws
.237 amps.

[That would actually require 13.27 volts into 56 ohms]

Can I put a 56 ohm 3 watt resistor in its place or am I totally out
in left
field?

Power = V^2 / R - so a 56 ohm resistor across 12v will dissipate 144/56 =
2.57 watts.

However, if it's going in a car, it will be running at 14v or more when the
alternator is charging - and 14^2 / 56 = 3.5 watts - so 3 could be a bit
marginal.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

 

[James Sweet]

Thanks, I chose a 5 watt just to be safe. Glad I did, didn't think about the
actual voltage.

Why put a resistor in there though? If the solenoid is bad why not just
leave it disconnected, or replace the solenoid with a new one? What's it do?

 

[Dave Plowman (News)]

Why put a resistor in there though? If the solenoid is bad why not just
leave it disconnected,

Probably to fool the warning system into thinking things are ok?

or replace the solenoid with a new one? What's it do?

I'd also be interested to know the purpose of the solenoid.

 

[Asimov]

"James Sweet" bravely wrote to "All" (28 Dec 05 06:59:23)
--- on the heady topic of "Re: Basic question (I think)"

JS> From: James Sweet <[email protected]>
JS> Xref: core-easynews sci.electronics.repair:352797

Thanks, I chose a 5 watt just to be safe. Glad I did, didn't think about the
actual voltage.

JS> Why put a resistor in there though? If the solenoid is bad why not
JS> just leave it disconnected, or replace the solenoid with a new one?
JS> What's it do?

He seems to me intent on disabling the seatbelt beepers. The simpler
thing if he doesn't like beepers is to disconnect the sqwawkbox.

A*s*i*m*o*v

.... I worked hard to attach the electrodes to it.

 

[T Hakemack]

OK, here's all the poop.
98-99 Dodge Quadcab trucks have a soleniod that has to be powered to put the
seat belt on. It's powered by a seat belt module under the seat that has a
pendulum(SP) in it that kills power in a wreck to the solenoids thereby
locking the belts. The seat belt module also ties into the Airbag system(I
haven't researched why). Anyway to make a long story short, I put a 2001
seat in it that doesn't use a module(Dodge did away with it after 99).
Basically all I'm doing it faking the module in to thinking the solenoids
are there so the seat belt light on the dash goes out while driving but
still works if you don't have your seat belt on.

 

[Wes.]

OK, here's all the poop.
98-99 Dodge Quadcab trucks have a soleniod that has to be powered to
put the seat belt on. It's powered by a seat belt module under the
seat that has a pendulum(SP) in it that kills power in a wreck to the
solenoids thereby locking the belts. The seat belt module also ties
into the Airbag system(I haven't researched why). Anyway to make a
long story short, I put a 2001 seat in it that doesn't use a
module(Dodge did away with it after 99). Basically all I'm doing it
faking the module in to thinking the solenoids are there so the seat
belt light on the dash goes out while driving but still works if you
don't have your seat belt on.

I would say the tie in to the air bag system is to adjust air bag timing
and inflation for an unrestrained pax/driver in the event of a crash.

Wes.