Murphy Almost Got Me

Have questions about the equipment used for macro- or micro- photography? Post those questions in this forum.

Moderators: rjlittlefield, ChrisR, Chris S., Pau

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Murphy Almost Got Me

Post by mawyatt »

Sir Edsel Murphy almost got me earlier this morning :?

While I was rearranging my experimental DIY S&S system one of the USB connectors metal shield slipped and shorted to the 5 volts and sparks flew, and may have also shorted to the +12 volts too :oops:

The entire setup went down and the Raspberry Pi rebooted, but I pulled the power to examine the damage, and thought I had destroyed some of the electronics. Couldn't find any obvious damage but decided to rearrange the motor driver boards and all the cables, as well as secure the interface & power board to the Raspberry Pi case top. I mounted the 3 motor controller boards to a foam board and used some new shorter USB cable I just received from eBay, then tidied up the other cables.

Re-powered up and checked the voltages, LEDs and such and everything appeared to survive, probably helped by the over-current on the regulators protecting things. Ran a couple S&S sessions and everything appears to be OK, in spite of my attempt to mess up some electronics :roll:

Here's what the setup looks like now, hopefully I won't have another episode :oops:

I've been running the setup for a couple weeks now, 24/7 to check for any potential problems and weed out any weak components, so I'll probably need to keep running everything a few more days/weeks just be be sure!

Best and Happy New Year,

Image
Image
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

Luisifer
Posts: 112
Joined: Wed Sep 05, 2018 1:40 am
Location: Czech Republic
Contact:

Re: Murphy Almost Got Me

Post by Luisifer »

I can only hope that it never ever happen to me. When i have quite different values on the stepper motor power line.
(50 V (lowered by trimmer in 60 V power source - Leadshine RPS608 ), 10.5 Amax)

Let the 2019 be the year of the success. :)

Image

RobertOToole
Posts: 2627
Joined: Thu Jan 17, 2013 9:34 pm
Location: United States
Contact:

Re: Murphy Almost Got Me

Post by RobertOToole »

mawyatt wrote:Sir Edsel Murphy almost got me earlier this morning :?

While I was rearranging my experimental DIY S&S system one of the USB connectors metal shield slipped and shorted to the 5 volts and sparks flew, and may have also shorted to the +12 volts too :oops:

The entire setup went down and the Raspberry Pi rebooted, but I pulled the power to examine the damage, and thought I had destroyed some of the electronics. Couldn't find any obvious damage but decided to rearrange the motor driver boards and all the cables, as well as secure the interface & power board to the Raspberry Pi case top. I mounted the 3 motor controller boards to a foam board and used some new shorter USB cable I just received from eBay, then tidied up the other cables.

Re-powered up and checked the voltages, LEDs and such and everything appeared to survive, probably helped by the over-current on the regulators protecting things. Ran a couple S&S sessions and everything appears to be OK, in spite of my attempt to mess up some electronics :roll:

Here's what the setup looks like now, hopefully I won't have another episode :oops:

I've been running the setup for a couple weeks now, 24/7 to check for any potential problems and weed out any weak components, so I'll probably need to keep running everything a few more days/weeks just be be sure!

Best and Happy New Year,
Glad to hear everything survived Mike.

Before my photography business I was in management in the Automotive industry (specifically prototyping, reverse engineering ECMs) and we used to work with OEM engineers from all over the world so I saw lots of sparks, fire and smoke from the smallest little errors and mishaps! It was almost everyday!

:shock:

Keep up the good work.

Happy New Year!

Robert

Lou Jost
Posts: 5942
Joined: Fri Sep 04, 2015 7:03 am
Location: Ecuador
Contact:

Post by Lou Jost »

I've been running the setup for a couple weeks now, 24/7 to check for any potential problems and weed out any weak components
Always a good practice. I guess you found the weak spot!

mawyatt
Posts: 2497
Joined: Thu Aug 22, 2013 6:54 pm
Location: Clearwater, Florida

Post by mawyatt »

Lou Jost wrote:
I've been running the setup for a couple weeks now, 24/7 to check for any potential problems and weed out any weak components
Always a good practice. I guess you found the weak spot!
Lou,

Yeah, it was me :? I'm the one that caused the short :oops:

Anyway, agree it's a good practice to "burn in". Failure modes for electronics is like a bath tub curve, high early failures decaying with time, followed by a low flat failure rate, then a increasing failure rate with time called "burn out". Reliability is specified as MTBF (Mean Time Between Failure). I never like MTBF term since it implies at least 2 failures, heck I don't want any failures!!

Best & Happy New Year,
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

Post Reply Previous topicNext topic