Oscilloscope Build Episode 277

[G+_Russ DiBennetto]

Oscilloscope Build Episode 277

 

This is my experience building the ~$20.00 Oscilloscope that was featured on Know How. First my background. I am in my mid 60ies and worked in Tech since my mid 20ies. I started doing component level repair, which included a lot of soldering. I used so soldier 100pin plasma 6” displays into word processors in the early 80ies. Later, I worked for a fortune 500 company where I did instrument interfaces into early (pre IBM PC) computers running Z-80’s and running CPM as an operation system. After that I installed our first Ethernet and later got into WAN using Enterprise grade Cisco routers and switches. Enough with my background.

 

Now for the build. First I found the 1/8 watt resistors impossible to read, even with a magnifying glass. I ended up measuring the 20 plus resistors with a multimeter. To keep them organized, I put a piece of paper on a clip board and taped the resistors onto the paper and labeling them with their value and “R” number (see attached photo).

 

The soldering was pretty much a piece of cake, except I accidently soldered one of the resistors in the wrong place. It was next to impossible to replace the resistor into the correct hole so I ended up surface soldering it to the proper pads. In the process, I accidently solder shorted one of the existing (pre soldered surface mounted resistors. I managed to take that resistor off and almost lost it but managed to remove the short and re-surface mount it.

 

The case took me a couple of days to assemble correctly in that there were no instructions that came with the kit. Finally I went to the web site where I purchased the kit and find a super-fast video that showed assembly.

I also had one of the long screws that came in stripped, luckily Ace Hardware had a replacement.

 

Now for the power supply. I had an old Plantronics power brick (I never throw away old power bricks) that was rated at 9VDC output @ 500ma. Perfect I thought but the actual voltage was 13.4VDC, too much for the scope to handle. I had a DC-to-DC adjustable regulator which I purchased for another project and being they were $1.97 each, I purchased four of them. I build an adapter (see image) and placed it in-line with the power brick adjusted down to 9.5VDC.

 

Although the triggering is a bit flakey and there is a definite display delay, the scope is working great and I am happy I built it.

 

I have included a few photos of the build and also a short 30 second video of the scope displaying a PWM output of an Arduino.

 

I welcome questions and comments.

 

 

 

[G+_Keith Mallett]

That's cool. I was just looking at the new hand held one from Banggood.

m.banggood.com - EONE ET201 2 in 1 Digital Intelligent Handheld Storage Oscilloscope Multimeter AC/DC Current Voltage Resistance Frequency Diode Tester Sale - Banggood Mobile