John Wiltrout's Blog

Problem detected with the Non-Slip Probe Tips

jw0752

Yesterday I was working to identify a group of SOT23 transistors that I had just salvaged from a circuit board. After crossing numbers and coming to a good guess of what the transistor was I used the analog meter to check the junctions. With this tec...
- 12 Aug 2018
Exploring a Holtek HT7039A-1 Voltage Detector

jw0752

Last night for the fun of it I disassembled a couple of circuit boards like this one: I am not sure of their function but they seem to be a small receiver that is controlling 2 SPDT Relays whose switch contacts exit on the pins. I have about a d...
- 12 Jul 2018
Insulation Properties of Dollar Store Nail Polish (Follow-up)

jw0752

This is a follow up on ntewinkel blog of a week or so ago: Nail Polish Short-proofing? Since I use dollar store nail polish as a circuit sealer and insulator I decided to do some tests to confirm my assumptions that it is a good insu...
- 19 Jun 2018
Shop-Tips From Nothing to Something

jw0752

This is a second chapter from my proto-book. I chose this article as it relates to a question the other day from Anonymous-532400 about designing circuits. While what I have done in this piece isn't exactly circuit design it is circuit modification a...
- 6 Jun 2018
Tech Tips - Reusable Solder Dispensers

jw0752

Back in January I began spending time writing short one page to 20 page articles for a book. I hoped to put together at least 50 of these little ideas from an old technician. I modeled them on the short series of blogs I did here on the forum a...
- 3 Jun 2018
A Palindrome Resistor

jw0752

OK this is really not worth writing about but it caught my OCD eye. Perhaps it is the electronics equivalent of a four leaf clover. I will have to buy a lottery ticket tomorrow and check out the hypothesis. I have ...
- 23 Apr 2018
The Non-Slip Probe Tips make it to market!

jw0752

I was really pleased today when a project that I have been working on for almost two years had a small success. The Non-Slip meter probe adapters have been a product that was developed and cultivated right here on element 14 with the help of my frien...
- 14 Apr 2018
Tale of Two Meters

jw0752

Today was a good day as two meters were added to my family of meters. I would not usually write about the addition of a meter or two but the contrast between these two meters is special. Many of you have experienced and appreciate the miraculous deve...
- 13 Apr 2018
Another Reason to Move to California - Retro Electronic Parts Store

jw0752

As if the nice weather wasn't enough of an incentive to move from my home in Wisconsin, where it is currently 10 degrees F and buried in snow, to sunny California, I recently came across this awesome retro electronics component store in Torrance ...
- 3 Feb 2018
A Meeting with Make Electronics Author Charles Platt

jw0752

In my wanderings today I had the honor of spending an hour and a half visiting with the Author of the wonderful Make Electronics and Encyclopedia of Electronics Books Series. These are some of the best entry level books available for those who want t...
- 28 Jan 2018
It's a Tree, It's an Antenna?

jw0752

I have no doubt that I am a little out of it. New things and ideas seem to come faster than I can assimilate them sometimes. This may be more common that I think but it is the first time I have seen one. At first glance I was impressed by ...
- 24 Jan 2018
element 14 Members meet in San Antonio

jw0752

Today Millie and I passed through San Antonio Texas and we had the opportunity to meet with genebren and his lovely wife for lunch. This gave us a great chance to compare interests and ideas about electronics. Face to face meetings add a new dimensio...
- 24 Jan 2018
Playing with a Variable Frequency Drive

jw0752

One of my sons Mario, who works repairing automated machines for a local manufacturer, was talking about the 3 phase power that they use. I told him about the interesting 3 phase generator that shabaz built and tested the other day and that I wanted ...
- 3 Jan 2018
Christmas Vacation Project - Building a Clap Switch Light

jw0752

Thanks to Christmas Vacation I had the opportunity to spend the day doing electronics with my 11 year old Grandson Ivan. We began with a small Chinese noise actuated clap switch. https://www.ebay.com/itm/VOS-Voice-Operated-Switch-DIY-Kit-Voice-S...
- 27 Dec 2017
Reverse Engineering a GFI Plug

jw0752

While getting dinner tables ready today for the coming Christmas Dinner the boss (Millie) asked me to get some wrinkles out of a plastic table cloth. After retrieving my shop hair dryer I began to heat the plastic cloth to remove the wrinkles. After ...
- 23 Dec 2017
Calibration of My 43 year Old BK Dynascan 1460 Scope

jw0752

For my 25th birthday in 1974 I bought a 10 MHz BK Dynascan 1460 Oscilloscope for $450.00. It was my first scope and I was servicing Audio Electronics at the time with an occasional TV thrown in. My primary job was as an independent service tech for 2...
- 18 Dec 2017
Defective Caliper

jw0752

Testplayers.brightcove.net/.../index.html This video can be ignored. I wanted to try the new video up load system.John
- 14 Oct 2017
A New Approach to a Bench Top Ammeter

jw0752

When I first found this Chinese Ammeter kit I bought it, as at $4.62 and free shipping it was a no brainer. https://www.banggood.com/ICL7107-Digital-Ammeter-DIY-Kit-Electronic-Learning-Kit-p-977902.html?rmmds=search&nbsp...
- 29 Sep 2017
My Muse is Gone

jw0752

For those of you who have known me and followed me over these last 4 years there has been one continuing theme. My Mom with deteriorating symptoms of Parkinson's Disease and me with furtive attempts to use electronics and technology to ameliorate her...
- 14 Sep 2017
Disaster Averted

jw0752

About a year ago I installed a Water Mains Shut Off system in my home. I blogged about it at the time and here is a link to the final Blog Post where I included a video: https://www.element14.com/community/people/jw0752/blog/2016/07/12/automatic...
- 1 Sep 2017
I Love Wire

jw0752

Yes I admit it, I confess, I Love Wire! A while back Alpha Wire announced the release of a new wire called Thermo Thin Hook-up Wire. Here is their announcement on e14 in case you missed it. https://www.element14.com/community/groups/a...
- 18 Aug 2017
Process Duration Timer (Final Chapter) Assembly and Testing

jw0752

If you have followed the previous 3 posts about this project you know that we are at the point where the rubber meets the road. I have now put the interface circuits, that were previously on bread boards, on to an Arduino shield board. The shield wil...
- 8 Aug 2017
Process Duration Timer Part (4) The Brain and Proof of Concept

jw0752

The purpose of the Process Duration Timer (PDT) is to provide a means to set up an experiment and time a process, whether it is the discharging of a battery, the discharging of a capacitor or some other process that one does not want to sit around an...
- 6 Aug 2017
Process Duration Timer Part 3 (Interfaces)

jw0752

I will begin this blog by showing you how I have mounted the power supply into the project box that will be used for the Process Duration Timer. After a lot of searching in my transformer grave yard I found one that will allo...
- 3 Aug 2017
Process Duration Timer Part 2 (Power Supply)

jw0752

Before I show you the power supply module for this project I thought I would share the basic block diagram of the different modules and how the power and control lines will interconnect. As any of the experienced builders on e14 will tell ...
- 28 Jul 2017