Continuity Tester Project in Nuts & Volts

Thread Starter

Rickrcomm1

Joined Sep 7, 2017
5
If anyone is interested in building this project in the last issue of Nuts & Volts, I’d be interested in pooling resources to either split the $60 ExpressPCB charge to convert the author’s ExpressPCB file for the board to Gerbers and go to OSHPark for the PCBs (preferred) or split the ExpressPCB charge for the PCBs.

Let’s see how many are interested. Looks like a very useful and though fully designed piece of test equipment.

Thanks,

Rick
 

dl324

Joined Mar 30, 2015
8,867
You didn't provide a schematic or link, but who would want to pay that much for a continuity tester when that functionality is available in most DVMs? Before I had a DVM, I used an analog ohmmeter.

My go to tester consists of 2 AA batteries and a flashlight bulb. I still find this tester to be more convenient than a DVM. I have several of them so I'll always have one handy.
 

Thread Starter

Rickrcomm1

Joined Sep 7, 2017
5
You didn't provide a schematic or link, but who would want to pay that much for a continuity tester when that functionality is available in most DVMs? Before I had a DVM, I used an analog ohmmeter.

My go to tester consists of 2 AA batteries and a flashlight bulb. I still find this tester to be more convenient than a DVM. I have several of them so I'll always have one handy.
 

Externet

Joined Nov 29, 2005
1,410
Agree with the pricing comments. Even the very best continuity tester I have ever seen/tried in my life in this planet does not deserve an inflated figure.

Used! ----> https://www.ebay.com/itm/Excelta-MB-1-Mini-Beeper-T62244/191818718936?_trkparms=ao=1&asc=20170105155410&meid=ae1179b5031b4f40b31c3e2144f96d95&pid=100705&rk=1&rkt=1&&itm=191818718936&_trksid=p2045573.c100705.m4780

Different model, new---> http://www.techni-tool.com/352TE001

Would really like to see the Nuts and Volts project principles...
 
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Thread Starter

Rickrcomm1

Joined Sep 7, 2017
5
I guess I assumed folks on this forum subscribe to the Nuts & Volts magazine. You can’t actually look at the article unless you’re a subscriber.

The point of this tester is that it puts a very small voltage - 200mV - across the probes. According to the article, Flukes put 7V across the probes. If you’re looking for shorts around a board, 7 volts on some component pins could damage the part. Also, this design gives an “instant” response- very useful if sweeping down a row of pins, like on a hand soldered SMT.

If you’re fine with what you have, that’s great. I’m just looking for someone interested in a continuity tester with these specs.
 

shteii01

Joined Feb 19, 2010
4,667
I guess I assumed folks on this forum subscribe to the Nuts & Volts magazine. You can’t actually look at the article unless you’re a subscriber.

The point of this tester is that it puts a very small voltage - 200mV - across the probes. According to the article, Flukes put 7V across the probes. If you’re looking for shorts around a board, 7 volts on some component pins could damage the part. Also, this design gives an “instant” response- very useful if sweeping down a row of pins, like on a hand soldered SMT.

If you’re fine with what you have, that’s great. I’m just looking for someone interested in a continuity tester with these specs.
Interesting that you mentioned Fluke. I assume by Fluke you mean dmm that uses 9V battery. So.......... Use dmm that use 2 or 3 1.5V batteries, that way the dmm can put out Maximum of 4.5V, but even that is not likely, like you have shown with Fluke, 9V Fluke will put out 7V, so 4.5V dmm will likely put out less than 3 volts, maybe as low as 2 volts.
 

Externet

Joined Nov 29, 2005
1,410
:( The bill of materials shows like 40 parts :(
I was unable to open the PC board image to check if it can be done on perforated board.
 

Thread Starter

Rickrcomm1

Joined Sep 7, 2017
5
Yes, author says it could be built on a breadboard. I just like to do PCB when possible.

But I just ran sone tests with my Fluke 83 III and its continuity voltage seems < 200 mV. But it triggers the beeper at ~110 ohms. The Nuts & Volts circuit triggers at 29 ohms according to the author.

There are a lot of parts but the active components are not expensive.
 
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