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lonewolfe
I'm curious what you all do to bench test electrical items? I'm just not very knowledgeable about electrical things. I have some gauges, fog lights and other items I'd like to be able to bench test but don't know the best way to power them. Our cars of course run on 12v systems. Is there some sort of device to use that allows one to adjust voltage?

I know this sounds like a dumb question but I'm sure there must be a safe way to test electrical devices for our cars.

Anyone?
falcor75
Something like this should work I guess.

http://www.ebay.com/itm/60V-5A-5AMP-Lab-Di...=item35cc32cb15
type47
use an old battery that you kept instead of turning in as a core and some wires with alligator clips. Charge the battery with a $20 Black and Decker trickle charger from local hardware store. Easy access to +12VDC and ground.....
dlestep
First, you need a bench.
Secondly, you need the right tools.
Then, you make the + thingys run around and smash into the - thingys.
If you can't make that happen, then you need to find someone who knows
what the fuck their doin' !
Otherwise, you can light your cigarette with the horn button, when you turn your lights on.
76-914
No such thing as a stupid question. Do you have a multi meter. If not buy one. They range from $3-$400. Most of your testing can be done using the om function of the multi meter. It will tell you if you have continuity or not. IOW, there is a clear unobstructed path for the elec to flow. Or as mentioned above, use an old battery. There are some very savvy and patient electrical gurus here. I'm not one of them so ask away. lol-2.gif
cary
QUOTE(falcor75 @ Jan 30 2014, 01:29 AM) *

Something like this should work I guess.

http://www.ebay.com/itm/60V-5A-5AMP-Lab-Di...=item35cc32cb15


That is cool ................
My other 100 year old 12v only finally died.
914GT
I use a cheap Harbor Freight power pack, under $30 with a coupon. Great for testing everything from car radios to starter motors. Has its own built-in trickle charger as well.

messix
Invest in some time at the university of Google and get comfortable with electrical terms and theory. If that makes your eyes glaze over then let some one else do the work ...... You will burn down your car if you don't "get it".
r_towle
All the devices on the car will require 12 Volts DC, so they can ALL be powered by a normal car battery. Nothing bad will happen.

The device is what calls for, or asks for the AMPS....which is the amount of 12 VDC current it needs....
Think of electricity like a river.
The speed of the river is the voltage
The width of the river is the AMPS

So a little 1 foot wide river wont do any damage, you can walk right through it...
A 100 foot wide river, same speed, will knock you over and drag you downstream....same speed.

Amps are what you need to learn about so you understand wiring sizes, and fuse selection.

You wont overload any electrical device, because it will only use what it needs for AMPS.

Probably a good thing to have a fuse inline just in case the device has a short circuit.
lonewolfe
Thanks for all the suggestions! And you are right. I do need to study up on electrical terminology. I didn't even know what to ask for. It looks like either an old car battery or a DC Power Supply should do the trick. I have purchased an ohm meter already.
r_towle
Keep asking questions.
Its how you can learn, and there is quite a bit of electrical knowledge here.

Rich
Tom
Giving someone advise on how to test electrical things when that person had admitted in knowing nothing about electricity, is bad advise.
Google "basic DC theory" and read up on some electrical theory before you start trying to hook up and test things and you will be much better off. There are a lot of very good websites that explain the basics well and then you will have an understanding when you start testing things and why they work or do not work. Hooking up and testing electrical things without any understanding will quite often result in some sparks and smoke.
If you are committed to testing yourself, some electrical knowledge is necessary and a good multi-meter so you can test the part with the multi-meter before hooking it up to power.
Tom
Spoke
QUOTE(Tom @ Jan 30 2014, 04:37 PM) *

Giving someone advise on how to test electrical things when that person had admitted in knowing nothing about electricity, is bad advise.


agree.gif

There is no general way to test items even for a 12V vehicle. One needs to be knowledgeable on every item being tested.

For example testing a dash light bulb will draw a little current (narrow river in Rich's explanation) at 12V but putting 12V across a starter will draw a lot of current.

Best thing to do if one is not schooled in EE is to ask questions here. The 914 world will help guide one through the testing of just about anything.
lonewolfe
Admittedly, I need to study up on all things electrical. That is why I asked first before going and destroying something. I tend to error on the side of caution and this is probably one of the reasons my restoration is slower than I'd like. Fortunately, I am very patient and am going through this car slowly as I am building it with the intention of keeping this car forever.

I really do appreciate all your feedback including suggestions as well as criticisms and warnings. It's all good to me!

messix
You can ruin some elctrical circuits if you connect them in the wrong polarity.

Google will help you understand the part you are trying to test., just look it up.

And multi meter also known as a volt/ohm meter is a very important tool to have and there is no sense trying to trouble shoot anything electrical on the car with out one.
lonewolfe
QUOTE(messix @ Jan 30 2014, 03:31 PM) *

You can ruin some elctrical circuits if you connect them in the wrong polarity.

Google will help you understand the part you are trying to test., just look it up.

And multi meter also known as a volt/ohm meter is a very important tool to have and there is no sense trying to trouble shoot anything electrical on the car with out one.



I bought a good quality multi meter and have some homework to do before diving into anything. I'll figure it out and probably have some more questions along the way!
r_towle
Don't let fear scare you away from learning.
On a bench, maybe you melt some wires, maybe you learn to NEVER do that again.

Some of us enjoy learning the hard way smile.gif
somd914
One bad thing about using an old battery is the amount of current that is readily available to melt your test leads or your device under test when a short or near short occurs. headbang.gif That's why we have fuse blocks. Especially for a novice, I'd recommend a low amperage power supply.

Also agree that a multimeter is a must - most troubleshooting is determining whether or not power is getting there, measuring resistance, and determining continuity. An inexpensive multimeter for $15-$30 can do all this just fine for occasional use like working on the teener.

As previously mentioned, search the web for a little education on electrical theory and on schematic reading.

Keep asking questions as you get further along...
lonewolfe
QUOTE(somd914 @ Jan 30 2014, 05:51 PM) *

One bad thing about using an old battery is the amount of current that is readily available to melt your test leads or your device under test when a short or near short occurs. headbang.gif That's why we have fuse blocks. Especially for a novice, I'd recommend a low amperage power supply.

Also agree that a multimeter is a must - most troubleshooting is determining whether or not power is getting there, measuring resistance, and determining continuity. An inexpensive multimeter for $15-$30 can do all this just fine for occasional use like working on the teener.

As previously mentioned, search the web for a little education on electrical theory and on schematic reading.

Keep asking questions as you get further along...


When buying a DC Power Supply, how many volts and amps are needed? I see they have 30v 3amp, 30v 5amp and 60v 5amp and on and on. Is a 30v 5amp adequate?
r_towle
For automotive testing 12 vdc, 20 amps
Should be more than enough for everything except a starter.
messix
12V regulated power supply's are not cheap, not what you are likely to want to spend money on for occasional hobby use.

using a 12v batter will be fine if you wire up your supply buss with a couple of inexpensive circuit breakers to limit fault current [the amount of power that will be available until cut out if the circuit is faulty or shorted].

using 5,10,20 amp breakers on different locations on a dc buss would work well.




CptTripps
I spent $ on a 30A regulated power supply about 15yrs ago when I knew nothing, and have never regretted it. Most of what you'll test falls WAY under that, so a 10A would likely do the trick.

I built a switch panel with 2-3 "momentary" switches and normal switches so I can test things too.

Multimeter is your friend...you can do no harm by reading ohms. His brother Google is a great guy too.
somd914
No need to spend big bucks on pro-level supplies for occasional testing.

Build your own with inexpensive components. A quick look found numerous articles discussing building 12 V supplies for powering car equipment.

FleaBay is crowded with pages of 12 volt supplies of all types.

To me a battery is space consuming, has to be kept charged, and as suggested current protected on the output with fuses or breakers. A supply is portable, always "charged", etc.

But the important thing is there are options, none are perfect solutions because we all have different needs and budgets. No matter what you do, just make sure you can't fry the item you want to test.
dlestep
QUOTE(messix @ Jan 30 2014, 10:25 PM) *

12V regulated power supply's are not cheap, not what you are likely to want to spend money on for occasional hobby use.

using a 12v batter will be fine if you wire up your supply buss with a couple of inexpensive circuit breakers to limit fault current [the amount of power that will be available until cut out if the circuit is faulty or shorted].

using 5,10,20 amp breakers on different locations on a dc buss would work well.

Don't get out much, do you ? BBROYWBVGW gave you a chubby in school, didn't it ?
Tom
Dave,
That W between Y and B should be a G. For green! dry.gif
And at the end, add GSN for resistor tolerance. 5%,10%,20%.
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Tom
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