Click here to read this mailing online.

Your email updates, powered by FeedBlitz

 
Here is a sample subscription for you. Click here to start your FREE subscription


  1. Linkdump: July 2015
  2. XL741: Principles of Operation
  3. Another take on Twisted Wire Bundles
  4. Lunch bags with the WaterColorBot
  5. Hackaday Prize Deadline
  6. More Recent Articles
  7. Search Evil Mad Scientist Laboratories
  8. Prior Mailing Archive

Linkdump: July 2015

    

XL741: Principles of Operation

XL741

Our two “dis-integrated circuit” kits are the Three Fives Discrete 555 Timer, and the XL741 Discrete Op-Amp. These two kits are functional, transistor-level replicas of the original NE555 and μA741 (respectively), which are two of the most popular integrated circuits of all time.

Last year, we wrote up a detailed educational supplement for the Three Fives kit, that works through its circuit diagram and discusses its principles of operation down to the transistor level. Today, we are doing the same for the XL741 kit, and releasing an educational supplement that explains how a ‘741 op-amp IC works internally, down to its bare transistors and resistors:

XL741 Documentation (PDF)

This ability to peek inside the circuit makes the XL741 a unique educational tool. In what follows, we’ll work through the circuit diagram, discuss the theory of operation of the ‘741 op-amp, and present some opportunities for experiments and further exploration.

You can download the supplement here: XL741 Principles of Operation (1.1 MB PDF)

Additional Resources:

 

 

 

    

Another take on Twisted Wire Bundles

Steve W. wrote in to share his improvement on the method for making wire bundles we wrote about:

 I’ve used the bend-it-over-and-stuff-it-in-the-chuck approach, but was not fully happy with it.

Binder clip on wood piece for drilling

So I drilled a 1/8″ hole in the back of a binder clip.  The drilling is easy if you clip a ~3/8 scrap of wood.

Wire twisting jig in drill chuck.

A 4-40 SHCS screw long enough to allow me to actuate the clip was not threaded all the way to the head, so I used a 1/4″ spacer between the binder clip and the 4-40 nut.  (Pan head screws are usually 100% threaded, but I would have had to look in the dreaded ‘other’ box to find one of those). Having the nut up against the chuck acted as a lock-nut.  I had been surprised when I first tried this that I did not have to work harder to keep it from loosening.  I had expected I might need a lock washer, and/or a second nut to lock the first.

Just grabbing the wires with the binder clip (my original plan) was not secure.  So I wrap the wires 180 degrees around a screwdriver bit and put that in the clip.

Works great, and it is quick to pop in and out when twisting many groups of wires.

Thanks for sharing your hack and sending the photos!

    

Lunch bags with the WaterColorBot

Spencer posted on our facebook page:

Thought you might enjoy this photo showing the WaterColorBot in action while inking some custom “brown bag lunches” for summer camp.

Final results…

And here is another. Fun project!

They look great— thanks for sharing them with us!

    

Hackaday Prize Deadline

The deadline for the Hackaday Prize is just a month away now!
BUILD SOMETHING THAT MATTERS
The creative energy and years of experience found in our huge community of Hackers, Designers, and Engineers is waiting to be unleashed. Let’s use that potential and move humanity forward.
We’re helping to judge the Best Product category, which has fewer than 50 entrants so far. The prize for Best Product is $100k and 6 months free rent in the Hackaday Design Lab with mentoring.
One example project is Eye of Horus, Open Source Eye Tracking Assistance, to increase accessibility for people who are disabled or physically separated from a work area.
Another entrant is DIPSY, an FPGA module in a DIP-8 package, shown here with an LED daughterboard in 6-pin DIL format.
Submissions are due August 17, so get your entries in right away! If you have questions or want feedback on your project, there’s a meetup on the hackaday prize channel on July 21 at 6 pm PDT.
We’re looking forward to seeing your entries!
    

More Recent Articles

You Might Like

Click here to safely unsubscribe from Evil Mad Scientist Laboratories. Click here to view mailing archives, here to change your preferences, or here to subscribePrivacy