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

In article , ml
wrote:

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

In article ,
Fred McKenzie wrote:

In article , ml
wrote:

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

hi

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

part number

http://www.radioshack.com/product/in...ductId=2103602

Model: 275-712
Catalog #: 275-712

In article ,
ml wrote:
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?

What is the rated power output of the power supply? If it's a small one
only feeding a pre-amp it likely can't drive the 5 watt or so lamp in the
switch. Which could take over 500mA at switch on. A better choice would be
an LED - only about 20mA or so.

Generally car stuff like this isn't too concerned about efficiency.

--
*Why are a wise man and a wise guy opposites?

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

In article ,
ml wrote:
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 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, labeled:
Gnd:

Connect to the -12 Volt output of your power supply, and the -12 Volt
lead of the preamp. it is also one side of the lamp.

Load:

This is the switched power for the lamp, and to the + 12Volt input on
your preamp.

Power:

This goes to your +12 Volts.


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?

What is the rated power output of the power supply? If it's a small one
only feeding a pre-amp it likely can't drive the 5 watt or so lamp in the
switch. Which could take over 500mA at switch on. A better choice would be
an LED - only about 20mA or so.

Generally car stuff like this isn't too concerned about efficiency.


Did you look at the link? There is no way the lamp is 5 watts. It
would melt the switch's body. It should be 10 to 50 mA. Think 'Grain
of Wheat' lamp.


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There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

In article ,
Michael A. Terrell wrote:
What is the rated power output of the power supply? If it's a small
one only feeding a pre-amp it likely can't drive the 5 watt or so lamp
in the switch. Which could take over 500mA at switch on. A better
choice would be an LED - only about 20mA or so.

Generally car stuff like this isn't too concerned about efficiency.


Did you look at the link? There is no way the lamp is 5 watts. It
would melt the switch's body. It should be 10 to 50 mA. Think 'Grain
of Wheat' lamp.

Whatever. But the principle remains - filament lamps have a high start up
current which could be too great for a small regulated supply.

--
*Never miss a good chance to shut up.*

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
What is the rated power output of the power supply? If it's a small
one only feeding a pre-amp it likely can't drive the 5 watt or so lamp
in the switch. Which could take over 500mA at switch on. A better
choice would be an LED - only about 20mA or so.

Generally car stuff like this isn't too concerned about efficiency.

Did you look at the link? There is no way the lamp is 5 watts. It
would melt the switch's body. It should be 10 to 50 mA. Think 'Grain
of Wheat' lamp.

Whatever. But the principle remains - filament lamps have a high start up
current which could be too great for a small regulated supply.


Where did he say the supply was that small? If it won't handle the
preamp & the lamp at the same time its too damn small, anyway. Even
small wall warts start around 200 mA.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

In article ,
Michael A. Terrell wrote:
Whatever. But the principle remains - filament lamps have a high start
up current which could be too great for a small regulated supply.


Where did he say the supply was that small?

He didn't.

If it won't handle the preamp & the lamp at the same time its too damn
small, anyway. Even small wall warts start around 200 mA.

FFS. Try measuring a small filament lamp start up current. Illuminated car
lamps switches could easily be too much for one - they might have to be
visible in the daylight.

--
*A chicken crossing the road is poultry in motion.*

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
Whatever. But the principle remains - filament lamps have a high start
up current which could be too great for a small regulated supply.

Where did he say the supply was that small?

He didn't.

If it won't handle the preamp & the lamp at the same time its too damn
small, anyway. Even small wall warts start around 200 mA.

FFS. Try measuring a small filament lamp start up current. Illuminated car
lamps switches could easily be too much for one - they might have to be
visible in the daylight.


I did. About 40 years ago. They were in the 10 to 50 mA range.

--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

In article ,
Michael A. Terrell wrote:
FFS. Try measuring a small filament lamp start up current. Illuminated car
lamps switches could easily be too much for one - they might have to be
visible in the daylight.


I did. About 40 years ago. They were in the 10 to 50 mA range.

So you know for sure what size lamp that switch uses? I couldn't see any
information on the website.

However, 50mA might well be too much for a marginal power supply - as I
said

--
*It is wrong to ever split an infinitive *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Fred McKenzie wrote:

In article , ml
wrote:

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

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

In article ,
ml wrote:
In article ,
Fred McKenzie wrote:

In article , ml
wrote:

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

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

The way you wired it was correct.

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

Could it simply be faulty? The easy way to check it is with a DVM - they
can be bought for pennies these days.

it's gotta be something simple

something is not right

I'd agree there.

--
*Reality is a crutch for people who can't handle drugs.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
FFS. Try measuring a small filament lamp start up current. Illuminated car
lamps switches could easily be too much for one - they might have to be
visible in the daylight.

I did. About 40 years ago. They were in the 10 to 50 mA range.

So you know for sure what size lamp that switch uses? I couldn't see any
information on the website.

However, 50mA might well be too much for a marginal power supply - as I
said


If it is that marginal it would be useless for the preamp, as well.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

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

In article ,
Gnack Nol wrote:

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

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