12 volt power for bench testing car parts?

[JeffreyNMemphis]

Hello Friends,

My clock is running slow. I think it is losing 15 minutes per day. This weekend I plan to take it out of the car and adjust the +/- to get it accurate. Which brings up this question:

What amps do electrical parts from the car need to function correctly and safely? I have a 12v battery charger with a 2 amp setting; would this work to run the clock on my work bench for a few days while I continually adjust closer to correct timing? I have other 12v power-supplies from household appliances, but don't know if the the amps would blow the clock. Also, I have some other electical parts I want to test besides the clock; what is the correct power source for bench testing automotive electrical parts?

Thank you in advance!

Jeffrey

[Tomguy]

Usually voltage is around 13.8 DC and a battery charger doesn't have a capacitor... I would say this matters but if your clock is the mechanical clock, really all that matters is you hook the (+) to (+)and (-) to (-) and voltage is around 12V. The reason is the voltage just sort of "winds" a spring that keeps the clock going. You can hear the louder tick every so often in the clock, that's the winding. I've found though that mine keeps time differently depending on the weather, in the cold it's slower and in the warm it's slow, but not as slow!

[JeffreyNMemphis]

Yes, it is the mechanical clock.. And I can hear it ticking.

I also want to test some other stuff that is automotive. What would you suggest as a power source for testing 12v car parts? I could use a car battery that is available... But my preference is for something powered by household current and converted to 12v like an appliance. My wife has been through several "Litter Maid" cat boxes that run on 12v converter and break eventually; so I have a 12v converter available. My first thought was my 12v trickle charger for car battery.

[GaryF]

Originally Posted by JeffreyNMemphis

What amps do electrical parts from the car need to function correctly and safely? I have a 12v battery charger with a 2 amp setting; would this work to run the clock on my work bench for a few days while I continually adjust closer to correct timing? I have other 12v power-supplies from household appliances, but don't know if the the amps would blow the clock. Also, I have some other electical parts I want to test besides the clock; what is the correct power source for bench testing automotive electrical parts?

Thank you in advance!

Jeffrey

Amps is a measure of the current flowing through a circuit which depends on the voltage and the power being consumed by the load. A 12v clock requires very little power and will only draw a small fraction of an Amp so any 12v source will be fine. If you wanted to test the window defrost element, Cigar lighter, fully loaded starter motor etc then you'll need a well charged battery to supply the current otherwise the supply will be overloaded and the voltage will drop too low to be of use.
Make sure your appliance adapters are supplying a regulated DC voltage!

[Arthur Dalton]

A good Buy for a 12V Bench Tester is one those Battery Jumper Paks...they have a battery, a built-in charger, Bat. Voltage condition LED readouts, along with a fused aux power plug/cig lighter port. Just need a cig plug with some decent test leads on it and you are there.
Perfect for Bench testing, along with their original design use as car jumper.

I have a Homebrew Bench tester that has all those features, plus built-in Amp meter and reverse polarity switching ...and long leads w/Bannana plugs.....easy to make and nice if you do a lot of electrical testing on the bench .. I also wired in a relay that powers a 12 V Halogen in case the Shop losses power......

*Note the Polarity Switch below the Triplet Amp meter..a nice feature for small motors/etc. that require reverse polarity for cw/ccw applications

[JeffreyNMemphis]

Cool box Arthur! Thanks to all for support and wisdom.

Life is good...

[Tomguy]

Originally Posted by Arthur Dalton

I have a Homebrew Bench tester that has all those features, plus built-in Amp meter and reverse polarity switching ...and long leads w/Bannana plugs.....easy to make and nice if you do a lot of electrical testing on the bench .. I also wired in a relay that powers a 12 V Halogen in case the Shop losses power......

*Note the Polarity Switch below the Triplet Amp meter..a nice feature for small motors/etc. that require reverse polarity for cw/ccw applications

Got a schematic for this? It looks like it could be a useful tool! I bet if you made a DIY that it'd be published in the DIY area under "Resources"!

[Arthur Dalton]

Not much of a schematic, as it is just a 12V power station.
So, each unit would be a specific diagram, depending on what one wants to do.

The circuits one would want to consider are:
A charging circuit to keep the 12v battery charged automatically.
A few Bannana outlets to let one have different sources
A Reverse polarity sw , [DPDT wired X]
And an Ampmeter than can be switched on for checking load draw .
And a couple of fuses for the unit ....one for 12v draw and one for charger 110 V supply line

As I mmentioned , most of these features are already in those Jumper Paks and they are also a handy item to have anyway, so that wouyd be the simpliest way for the average DIYer. i ACTUALLY SEE THESE GET THROWN OUT B/C THE BATTERY CRAPS..SO THEY ARE THE PERFECT STARTING CHASSIS FOR A pOWER STATION B/C THEY HAVE THE BAT CHARGER CIRCUIT ALREADY IN THEM, ALOMG W/BAT COND led ..SO A COUPLE OF WIRING CHANGES AND YOU ARE ALL SET.
Wooops Cap lock again and I'm aware of it OK??????????????????????

Also , to simplify the circuits, one could use different 12v out bannanas for polarity and Anp draw leads ..that will eliminate any switching/switches...you just label each outlet +/- or Amp 12V Out.

[250 Coupe]

If you want a AC powered unit, check out this from Radio Shack.

If you know a HAM, ask him if he's got a spare since they are used to run mobile radios while in the shack.

I think Fry's has them as does Parts Express.

Michael

[Arthur Dalton]

Hardly useful for an Auto Bench tester ..it is only 3 Amps..it is for radios..not car part testing.

[250 Coupe]

Originally Posted by Arthur Dalton

Hardly useful for an Auto Bench tester ..it is only 3 Amps..it is for radios..not car part testing.

Depends on what you are testing. It will run a clock, radio, solenoid valve, choke heater, nearly all the lamps and a bunch of other stuff. Won't power a headlight or window motor.

It seems to fit the description of what he is after.

You can power a mechanical clock from a Polaroid SX70 film pack battery.

Michael

[Arthur Dalton]

Not to be considered an Automotve Bench Tester w/3 A circuitry.

A Bench Tester will power anything on a car.........

He would be better off with a 10 A Battery Charger..........or better yet, for the same $$$$ , a 12 Jumper Pak as I suggested. That will power any part and can Jumper a car besides, and has a built-in 110 V ac/ charger to boot............

[250 Coupe]

Fine