lighted switch help

[ml]

hi

not really familiar with this stuff, thought it would be simple but i
got stuck

I have a preamp (low power) it gets 12v and i have a power supply
also 12v(DC)


i bought a lighted toggle/rocker switch lighted from radio shack

my goal was to just have the switch turn on/off the amp and light in
the on position


the switch has 3 legs labled

gnd

load

power


sounds simple, but seems something is not quite right



I assumed gnd was ok to tie everything to

so i have gnd from preamp gnd from pwr supply and i connected to gnd
on the switch

i assumed load was supposed to goto the pos on preamp

and power whent to pos of the supply


blew fuse i think power also switches to gnd or something i
dunno


anyone have experience with this type of switch from RS and how to hook
it up?


thanks

 

[Fred McKenzie]

the switch has 3 legs labled

gnd

load

power

ML-

What is the Radio Shack part number? I would have assumed the same as
you. I wonder if the switch might have been assembled with the labels
backwards?

With the switch in the OFF position there should be an open circuit
between Power and Gnd, and lamp resistance between Load and Gnd. With
the switch in the ON position, Load and Power should be shorted, and
lamp resistance between either and Gnd.

That is assuming the lamp is intended for 12 Volts. If it was intended
for 120 Volts, it most likely would be a neon lamp in series with a
resistor, and would measure as an open circuit.

Fred

 

[ml]

ML-

What is the Radio Shack part number? I would have assumed the same as
you. I wonder if the switch might have been assembled with the labels
backwards?

With the switch in the OFF position there should be an open circuit
between Power and Gnd, and lamp resistance between Load and Gnd. With
the switch in the ON position, Load and Power should be shorted, and
lamp resistance between either and Gnd.

That is assuming the lamp is intended for 12 Volts. If it was intended
for 120 Volts, it most likely would be a neon lamp in series with a
resistor, and would measure as an open circuit.

Fred

hi

thanks for responding it's 12v dunno if it's led or lamp

part number

http://www.radioshack.com/product/index.jsp?productId=2103602

Model: 275-712
Catalog #: 275-712

 

[ml]

ML-

What is the Radio Shack part number? I would have assumed the same as
you. I wonder if the switch might have been assembled with the labels
backwards?

With the switch in the OFF position there should be an open circuit
between Power and Gnd, and lamp resistance between Load and Gnd. With
the switch in the ON position, Load and Power should be shorted, and
lamp resistance between either and Gnd.

That is assuming the lamp is intended for 12 Volts. If it was intended
for 120 Volts, it most likely would be a neon lamp in series with a
resistor, and would measure as an open circuit.

Fred

Hi folks

appreciate the head up regarding power to the lamp, my supply
would have enough power to light a small lamp

what i didn't get is a way to wire it up , which was my question

one person responded back with exactly the same why i listed it hooked
up which didn't make sence to me since i listed it as that didn't
work

clearly something is off on these switches googling around
others agree but no one listed (on the other sites) how to
actually hook it up

it's gotta be something simple

something is not right

 

[Gnack Nol]

Trimmed

Hi folks

appreciate the head up regarding power to the lamp, my supply
would have enough power to light a small lamp

what i didn't get is a way to wire it up , which was my question

one person responded back with exactly the same why i listed it hooked
up which didn't make sence to me since i listed it as that didn't
work

clearly something is off on these switches googling around
others agree but no one listed (on the other sites) how to
actually hook it up

it's gotta be something simple

something is not right

I would think from the labels that you had hooked it up right. A simple
test would be to use an ohmmeter and check that the connection between
power and load actually switches when the rocker is moved from position to
position. If it does once again you should check the resistance from the
gnd terminal to each other terminal with the switch actually off and see
if there is a possibility the led or bulb is actually shorted.

Generally a led will read as an open circuit unless your meter supplies at
least 3v to the test leads while a lamp will read a low resistance.

A possibility also exists that your supply is putting out a high level of
ripple and could be causing the led to act as a short. This possibility
can be checked by hooking up your multimeter and monitoring the amount of
AC present.
Small wall warts usually contain little or no filtering and depend on the
equipment its meant to power for final filtering and some are pure AC.

If this is the problem a diode with the cathode connected to power ground
and the anode connected to the witch ground terminal might solve the
problem.



Since the switch is intended for automotive use it is also possible that
the indicator is a high current lamp and overloading your supply.


Gnack

 

[ml]

Trimmed

I would think from the labels that you had hooked it up right. A simple
test would be to use an ohmmeter and check that the connection between
power and load actually switches when the rocker is moved from position to
position. If it does once again you should check the resistance from the
gnd terminal to each other terminal with the switch actually off and see
if there is a possibility the led or bulb is actually shorted.

Generally a led will read as an open circuit unless your meter supplies at
least 3v to the test leads while a lamp will read a low resistance.

A possibility also exists that your supply is putting out a high level of
ripple and could be causing the led to act as a short. This possibility
can be checked by hooking up your multimeter and monitoring the amount of
AC present.
Small wall warts usually contain little or no filtering and depend on the
equipment its meant to power for final filtering and some are pure AC.

If this is the problem a diode with the cathode connected to power ground
and the anode connected to the witch ground terminal might solve the
problem.



Since the switch is intended for automotive use it is also possible that
the indicator is a high current lamp and overloading your supply.


Gnack

thanks for the reply, i can light the bulb or led so it's
bad my supply is fine, no ripple and it has enough amps
for the job good theory thou

i'll have to see apprantely the diagram on the switch could be
wrong i dunno

but the fact that others have the smae problem at lest means i am
not crazy


guess i need to really figure it out somehow

again thanks very much