Automation and system control engineering and development
Hi everybody! Welcome to Ken's Corner! I use this space to write about things that I have an opinion on. I'll try to post something here every month, so check back often. If there's a subject or a question you would like me to address, send me a note, I'd love to hear from you!
Or bazaar machines designed to exude secrets embedded in cyphers.
By Kenneth K. Whiteman
This installment’s subject is about what’s really important in our lives.
The time we spend with family and friends, sharing a great meal, and watching football is good for the soul. But most importantly, let’s be sure to give thanks to God for giving us such a bounty.
I’m not going to give a lesson in history, or suggest you celebrate in any particular manner.
I’ll just say “Happy Thanksgiving” to you and your family!
I will share a recipe for a turkey brine I use every year. This brine keeps a turkey moist and adds some new flavors. Enjoy!
See ya’ next time!
1 large onion, cut into 4ths
2 large oranges, cut into 4ths
2 lemons, cut into 4ths
2 pears, cut into 4ths
1 tablespoon whole peppercorns
3 cinnamon sticks, broken into approximately 1” lengths
4 or 5 cloves…Cloves are very strong, use more or less, adjusting to taste.
2 bay leaves
1 teaspoon cayenne pepper
1 cup brown sugar
1/2 teaspoon sage
1 teaspoon celery powder
2 cups salt (whole box)
1 bottle (2 liter) of ginger-ale
water – enough to make plenty of brine to completely cover turkey
Turkey must be thawed and cold.
Select a container large enough to hold turkey and completely cover with brine.*
Mix all ingredients thoroughly in selected container.
Place turkey in brine solution. Insure bird is completely covered in brine.
Close, cover, what-ever. Keep cold by adding ice around outside of container. Check every couple of hours.
Soak for at least 30 hours.
About every 6 or 8 hours, lift the bird up to allow the brine to circulate under the bird for a minute or two.
*Use a large garbage bag (Double bagged), and soak in the kitchen sink. Close the garbage bag and place ice around the outside of it. Cover the entire sink and bag with several bath towels.
Use a large cooler. Be sure there is plenty of ice surrounding the bird.
Well this installment is a bit tongue-in-cheek. Sure, the title is a Star Trek reference, but in many cases, I have considered it par for the course in a lot of areas.
Take Microsoft’s path changes in the last few years. We have had to retire most of our Windows XP machines, many of which were still perfectly operational. But because of no further support from Microsoft, they have become a virus & hackers liability. If you’re like me you probably still have an old system around and still use occasionally. I offer this: taken for what it is, we learned a lot about what we should have done in the first place.
Microsoft is no exception. Does anyone remember the DOS 4.0 debacle? I spent hours poring over books trying to figure out if it was possible to rebuild a FAT table. No such luck…
Were you one of the many whom had decided to go with the BetaMax option only to discover that VHS was the chosen one? And when we did finally accept VHS, they replaced it with DVD’s, and are now in the process of replacing those with Blue Ray!
And yes, I still have vinyl and cassettes (dare I say 8-tracks?) around here somewhere. Ugh…makes my head spin.
But you know, technology is a wonderful thing. The new operating systems look and promise to be the best they have ever been. I do not miss having to rewind video tapes. The music sounds way better and no popping sounds! I no longer carry a pager, and I keep my life on my smart phone. I haven’t sent a FAX in so long, I don’t even know where to go to have one sent!
Oh, how I long for the simpler days. Waiting for the mailman to bring me important news and information. The newspaper was the best source of local, national and even world news and events. The Sunday comics read in bed with Mom, Dad and all the siblings. Fun times. Easier times.
So now I just face life head on and take it as it comes, because as I said, resistance is futile!
See ya’ next time!
This is the first of what I hope to be several subjects of which I have an opinion on!
So, I’m sharing, and hoping you may find these tidbits useful.
I’m going to try to write something every few weeks, so if you have an area, or subject that you would like me to address, drop me a line! I’d love to hear from you!
My first article “The Art of Noise Management” touches on an area that I deal with quite often. So read and enjoy and if you have questions or comments, send em’ to me!
The Art of Noise Management
By Kenneth K. Whiteman
Many times I’ve been asked ‘why my product is acting weird? The signals are noisy and unstable.’
The truth is noise management is not something to be taken lightly. Somewhat unpredictable, I have solved problems by simply rotating a sensor, or moving a receiver a couple inches. Sometimes standing in front of the unit is sufficient to alter the signal. The culprit, more times than not is ground noise. So here are a few tips from my bag of experiences.
Rule #1: NEVER run AC wires in the same conduit/pathway with DC wires.
Rule #2: NEVER run Signal wires and AC wires together.
Ok, now that we’ve got that out of the way…
Let’s talk about AC Power systems, primarily 120VAC circuits.
Typically, Hot is Black, but may be Red. Neutral is White, and Ground is always Green. When the 110VAC enters your building thru the Tap on the outside, it’s important to insure that the Green and the White wires are securely connected together on the grounding bus bar. Yes, I said Green and White. This is the ONLY place where the two different circuits/wires should be connected together.
Very likely there is also a thick copper rod pushed deep into the earth and a green wire attached. This is to assure a good earth ground. All of these connections need to be good solid/tight connections, as they can be a source for noise.
Routing AC power from the main breaker box.
This is important, so listen up!
The Black (and/or Red) wires that run from the breaker are the hot side. It will be accompanied by a White wire and a Green wire, both of which should be attached to the grounding bus bar. From this point on, never again shall the White and the Green connect. The White is referred to as the return, and the Green is the Safety Ground.
The White wire will carry the return current for the circuit, and the Green will serve as a shunting circuit should a short occur between the Hot and oh, say the chassis, or if the white wire should become disconnected.
Connecting to switches, sockets, etc.
Here again good tight connections are essential. I have found in the past that inserting the stripped end of the wires into the convenient little holes on the back of most switches and sockets are a good source for noise. Don’t use them. Wrap the wire around the connection screw and secure with the screw. Yes, I know it’s legal to use the little holes, but then again, we’re trying to manage noise, so…
Be sure to attach a green wire from the switch or socket grounding frame to the green wire, and insure it’s a good solid connection. You may well see one set of wire coming in and one set of wires leaving. This is the Daisy-chain method, and again, good solid connections are a must here as well.
Connecting to DC controlled circuits.
When combining AC and DC circuits, plan carefully to route each in such a way as to minimize proximity to each other. If you must cross them, try to cross them at a 90 degree angle.
Routing DC power from the DC power supply.
Here, pretty much the same principals apply. Good solid connections, avoid proximity to AC circuits, etc.
There are several conventions concerning wire color, Red is positive, Black is negative/ground. Another convention is that White is hot/positive, and Black is negative/ground. There are other methods as well. Whichever method you chose, it’s wise to get it right and remain consistant.
When planning for you DC power requirements, supply filtering is an area that should be reviewed carefully. Place any external filtering components as close to the power supply as is feasible. In some cases it may be necessary to provide additional filtering very near other devices attached to the same power source.
DC Wiring Methods:
Ok, let’s get specific on the DC wiring!
Depending on the load of each component/sub system attached to the DC power source should dictate the number and size of the wires used. A good rule of thumb is set the value of the load to 70% of the amperage limit of the conductor/wire.
Fusing each path/circuit is also a good idea in case something does go wrong, you don’t end up damaging other circuits when the power supply is stressed beyond its limits. The fuse will stop this from happening by constraining the fault to only the circuit feeding it. Always fuse the Hot or Positive side, never the Ground or Negative side.
When attaching to the power supply, use a method known as the “Star” connection, meaning that all the wires connect to a single point. One method of implementation is a terminal strip. When selecting a location to attach each individual circuit manage them in such a way as to put the higher load circuits closest to the source feed end of the terminal strip. Also, feeding the terminal strip in the center as opposed to one end is a better way to go.
DC Ground/Negative Circuits:
Now for the negative(ground) side, the best scenario is to take a large gage Green wire to a chassis mounted ground lug and secure it well. This is important because this is where you are going to establish the three (3) types of ground circuits. They are as follows:
This is the most critical of the 3 ground types. You must be very judicial in making certain that you do not create a ground loop. What is a ground loop you ask? It can best be described as a single point that has multiple paths to ground. The problem here is that the length of these paths are different from one another, and you also create a condition that can and very often does develop a charge between the paths much like a capacitor. Now you have an elevated value for ground, and almost certainly a noise generator. In this context, keep it simply. One wire to ground for each circuit. Again we will want to utilize the “Star” method back to the power supply. Here you will want to try to keep the analog ground as segregated as possible from everything else. If your signals are running on shielded cable, be sure to terminate the shield drain as close to the connection as possible, yet still remain serviceable. Only terminate one end of the shielded cable. On the opposite end, trim off the braid and insulate with heatshrink tubing or some other insulating material.
This can be the single largest contributor of noise in a DC system. Consider this; your microprocessor is running an oscillator with frequencies in the megahertz range, flip-flops are flopping, ring counters are ringing…it’s just a noisy environment! Remember, typically analog circuits are high input impedances so that their being attached to a signal has almost no effect on the signal it’s connected to. That means almost no input current, and so we are monitoring voltage changes, and guess what noise is? Ok, don’t get discouraged. Good decoupling and filtering practices is the key to success. Run a little bit bigger wire gauge and in this case, it’s ok to pick up several points along the way. Do get carried away however, 1 path is likely only looking for trouble. When you are placing digital ground wires, try to avoid sharp bends as these tend to transmit noise as opposed to a slow/sloping curve.
Ok, this the most forgiving of the 3 types. The power supply should do a pretty good job of filtering the DC thru the use of large capacitors and inductors. Any additional filtering you can provide won’t hurt. Be sure to use sufficient gauge wire to carry the return current back to the power supply grounding point.
In all 3 of the above types of grounding as well as the power wiring, carefully think thru the routing, considering the currents that will be traveling thru the conductors.