The Ford Barn

Tom Wesenberg · 07-26-2012, 06:36 AM

I made my first cutout tester in the top picture several years ago. I used a small 15 volt DC transformer for the power supply and used a hair drier heating element for one of the variable resistors. It works great to test the voltage the cutout kicks in and out, and the LED will show when the contacts pass electricity. This works fine in most cases, but I wanted a tester that showed how well the contacts work when under load, so I made a new tester this past winter.

I bought a wood jewelry box, and also an aluminum box to store the tester in, at the second hand store for a couple bucks each. I removed the fuzzy liner from the jewelry box and used a milling bit in my drill press to cut recesses for the components. I use a couple 1.5 ohm 55 watt wire wound resistors in parallel for the load. The toggle switch is used to switch the volt meter from cut in voltage reading to voltage drop across the cutout contacts reading. I push the button when I'm ready to test. The heavy cables on the left are clipped onto a 6 volt battery, and the red clip on the right goes to the cutout ground, while the black is the input for the cutout and the yellow is the output.

My 3/4 ohm load isn't critical since the main thing is to know the voltage drop across the contacts of a known good cutout, then use that reference to compare other cutouts being tested under the same load. If my good original cutout shows a .2 volt drop across the contacts with this 3/4 ohm load, and I then test another cutout using the same load and get a reading of .5 volts, I know the contacts aren't doing a good job.

This tester is handy to bench test cutouts, but to test them on your car you just need to connect the voltmeter across the input and output terminals and read the voltage. The closer to 0 volts the better the contacts. If you are making this check on the car and have a voltage regulator inside the generator, then you need to turn on the lights to make more current flow. Remember, when testing for a voltage drop across a connection, you need current flow, and not just voltage. Generators without an EVR will have a set current flow depending on where the adjustable brush is set.

This tester is also handy to check the current draw of a horn or light bulb, etc.

RJ · 07-26-2012, 07:12 AM

Tom very nice you should send it along to the Restore or Model A News for a future article.

Terry, NJ · 07-26-2012, 07:27 AM

Tom! You not only produce very useful things, but they're very well made and a pleasure to look at.
Terry

newshirt · 07-26-2012, 07:40 AM

That's impressive! But maybe you have too much time on your hands.

Have you considered enhancing the tester with shock vibration to simulate the harsh physical environment of driving down a washboard road? (Do bad cutouts ever pop open under those conditions?) I'm thinking of a small fixture with electric motors on cams that jiggle and shock the cutout. Just a thought as I mused at your handywork...

Great work!

Tom Wesenberg · 07-26-2012, 08:01 AM

Quote:

Originally Posted by newshirt

That's impressive! But maybe you have too much time on your hands.

Have you considered enhancing the tester with shock vibration to simulate the harsh physical environment of driving down a washboard road? (Do bad cutouts ever pop open under those conditions?) I'm thinking of a small fixture with electric motors on cams that jiggle and shock the cutout. Just a thought as I mused at your handywork...

Great work!

Thanks guys.

Now, who has too much time on their hands?

LOL

The Nike Hercules missile accelerates from 0 to Mach 2 1/2 by the time it reaches the end of the launch rail and if that doesn't pop open the relays in it's guidance system, I don't think you need to worry about bumps in the road cushioned by springs in the Model A.

Elcastor · 07-26-2012, 09:18 AM

Sponsored Links (Register now to hide all advertisements)

For once in my life I wish I lived near Minneapolis.

Mitch//pa · 07-26-2012, 10:17 AM

U the man

mngreen · 07-26-2012, 11:55 AM

Where's the cat's whisker??

Tom Wesenberg · 07-30-2012, 12:35 PM

Quote:

Originally Posted by mngreen

Where's the cat's whisker??

It's in the cigar box with the crystal radio some old timer built many years ago. I went to the estate sale and this guys house was so full of stuff (mostly electrical, but actually lots of everything) that the relatives had to bring in two large dumpsters to make a walking path. There sure was a lot of good bargains though, including a very early Harley engine.

tbirdtbird · 07-31-2012, 10:59 PM

Very nicely executed, indeed.
"This tester is also handy to check the current draw of a horn or light bulb, etc." As you are prolly aware, they make a hand-held induction dc ammeter that you can just hold over the wire in question and it will indicate the amp draw, for those folks less creative than Tom.

This is but one source
http://www.kansaswindpower.net/meters.htm

they are avail. in several ranges. I have a 30-0-30 for routine checks and a 200-0-200 to measure starter draw

07-26-2012, 06:36 AM	#1
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Making a Cutout Tester I made my first cutout tester in the top picture several years ago. I used a small 15 volt DC transformer for the power supply and used a hair drier heating element for one of the variable resistors. It works great to test the voltage the cutout kicks in and out, and the LED will show when the contacts pass electricity. This works fine in most cases, but I wanted a tester that showed how well the contacts work when under load, so I made a new tester this past winter. I bought a wood jewelry box, and also an aluminum box to store the tester in, at the second hand store for a couple bucks each. I removed the fuzzy liner from the jewelry box and used a milling bit in my drill press to cut recesses for the components. I use a couple 1.5 ohm 55 watt wire wound resistors in parallel for the load. The toggle switch is used to switch the volt meter from cut in voltage reading to voltage drop across the cutout contacts reading. I push the button when I'm ready to test. The heavy cables on the left are clipped onto a 6 volt battery, and the red clip on the right goes to the cutout ground, while the black is the input for the cutout and the yellow is the output. My 3/4 ohm load isn't critical since the main thing is to know the voltage drop across the contacts of a known good cutout, then use that reference to compare other cutouts being tested under the same load. If my good original cutout shows a .2 volt drop across the contacts with this 3/4 ohm load, and I then test another cutout using the same load and get a reading of .5 volts, I know the contacts aren't doing a good job. This tester is handy to bench test cutouts, but to test them on your car you just need to connect the voltmeter across the input and output terminals and read the voltage. The closer to 0 volts the better the contacts. If you are making this check on the car and have a voltage regulator inside the generator, then you need to turn on the lights to make more current flow. Remember, when testing for a voltage drop across a connection, you need current flow, and not just voltage. Generators without an EVR will have a set current flow depending on where the adjustable brush is set. This tester is also handy to check the current draw of a horn or light bulb, etc.

07-26-2012, 07:12 AM	#2
RJ Member Join Date: May 2010 Posts: 61	Re: Making a Cutout Tester Tom very nice you should send it along to the Restore or Model A News for a future article.

07-26-2012, 07:27 AM	#3
Terry, NJ Senior Member Join Date: May 2010 Location: Bucks Co, Pa Posts: 3,740	Re: Making a Cutout Tester Tom! You not only produce very useful things, but they're very well made and a pleasure to look at. Terry

07-26-2012, 07:40 AM	#4
newshirt Senior Member Join Date: Jan 2011 Location: Colorado Springs Posts: 868	Re: Making a Cutout Tester That's impressive! But maybe you have too much time on your hands. Have you considered enhancing the tester with shock vibration to simulate the harsh physical environment of driving down a washboard road? (Do bad cutouts ever pop open under those conditions?) I'm thinking of a small fixture with electric motors on cams that jiggle and shock the cutout. Just a thought as I mused at your handywork... Great work! __________________ Ray White

07-26-2012, 09:18 AM	#6
Elcastor Senior Member Join Date: Oct 2010 Location: Oregon and Baja Mexico Posts: 617	Re: Making a Cutout Tester Sponsored Links (Register now to hide all advertisements) For once in my life I wish I lived near Minneapolis. __________________ Ben Purkey Mexico and the Pacific NW http://www.martin-parry.com/

07-26-2012, 10:17 AM	#7
Mitch//pa BANNED Join Date: May 2010 Location: Bucks County, PA Posts: 11,454	Re: Making a Cutout Tester U the man

07-26-2012, 11:55 AM	#8
mngreen Senior Member Join Date: Jul 2010 Location: Rancho Santa Margarita, CA Posts: 155	Re: Making a Cutout Tester Where's the cat's whisker??

07-31-2012, 10:59 PM	#10
tbirdtbird BANNED Join Date: May 2012 Location: inside your RAM Posts: 3,134	Re: Making a Cutout Tester Very nicely executed, indeed. "This tester is also handy to check the current draw of a horn or light bulb, etc." As you are prolly aware, they make a hand-held induction dc ammeter that you can just hold over the wire in question and it will indicate the amp draw, for those folks less creative than Tom. This is but one source http://www.kansaswindpower.net/meters.htm they are avail. in several ranges. I have a 30-0-30 for routine checks and a 200-0-200 to measure starter draw __________________ '31 180A