February 26, 2023

Yesteryear
One year ago today: February 26, 2022, problems in Buckhead.
Five years ago today: February 26, 2018, 1 pub for 7,500 people.
Nine years ago today: February 26, 2014, the Belekin.
Random years ago today: February 26, 2011, from the 1700s.

           What a glorious day. My new thermometer housing helps give a reading of 72°F and I was up early soldering. I was in the mood and I’ve needed a sharp desk lamp for some time. I have not yet found the bulb for the big lamp. I needed something small where I could work above the shadow line and this Dollar Tree gizmo was the ticket. It was battery powered but ate batteries because you would always forget to turn it off. Now it is hard wired as shown here, though I managed to lose the off-on switch. I’ll rig something up. This lamp has immediate employment and one is for photos.

           Below is such a picture already, showing the pin arrangement on a mechanical relay. I’ve got enough [relays] to proceed with building the NAND gate demo and one of the first uses of this spot lamp was to find relays with compatible pin outs—the numbers can be hard to read. You get not only neat pics, but also follow along my lesson on the most common pin arrangement with these puppies. Wow, I can hear you saying, just look at the clarity of these photos, why that spot lamp was a brilliant idea, get it, brilliant. Anyway, here’s the lecture keeping in mind there are variations that you should check for prior to wiring anything. You are going to forget I said that and make mistakes, but carry on.

WARNING - THESE PHOTOS AND COMMENTS ARE FROM CLUB EXPERIMENT NOTES,
NOT OFFICIAL SOURCES.
           I find it always helpful to turn these relays right side up. This is your typical five-pin automotive fuse. Never pay for store fuses when you can get a bucket full for five bucks at the junk yard. Send Agt. M over, he’s great for such tasks. I advise you to seek out these “Ford” style [relays] and stick to them. First challenge is learning the pins, there are five of them but you will usually use only four. Take them in logical order. The relay is used to turn things off and on depending on the signal present at the bottom pin. This is usually labeled “30”. There are two pins parallel to this signal pin, shown here as power in and power out. Stop and think about this arrangement for a moment. Here’s my conclusions.

           These must be the two pins that operate the relay, a magnetic coil inside the case that opens and closes a switch. Also, power will flow through this relay when there is power at the signal pin—and this is the part that threw me. The power at the signal pin never flows through this relay. It only controls whether the relay is off or on—I think. The power in and ground are usually respectively labeled “85” and “86”, again double check as this writing is only a description of the theory behind these devices. Further checking shows that although the case is marked that pin 86(+) goes to pin 85(-), the relay doesn’t seem to care. Current either direction produces the same results.

           Now the interesting part. Look at the two pins that are “sideways”. You will usually connect only one of these to your circuit. One pin is in the Normally Open position, the other is Normally Closed. A moments thought will give you all the logic needed to operate the relay. These pins are usually labeled “87” and “87A”, always test first. Understanding this arrangement is an excellent way to understand gates, where power is often needed to turn the switch off. Both pins seem to go to -0 volts when there is no power to pin 30. Applying power to pin 30 sends 12 volts to pin 87. This voltage matches the input from the power supply. Pin 87A doesn’t change no matter what I do.
           One thing for beginners to watch for is when the pins are labeled in ink. Normally Open is often shown as NO, causing people to avoid that pin. Yet, it is the one you most often want to use. Don’t be surprised if the signal voltage is smaller than the power voltage. That is what I’m testing for this morning. These relays are not consistent, and I’m going through what I have to find the ones that have the smallest voltage that trips the relay. I’ve already found two that work at 8 volts. (Automotive relays are designed to work with 12 volts).

           Since the robot club maxes at 9 volts, these “bad” relays make life easier. That’s your homework on relays. I’m designing a gate which will likely wire both the normally open and normally closed positions. If you follow that handily, you’re doing better than me when I got started. I may design a testing device for these, as some have odd characteristics like they won’t work without a common ground, or relays that work “backwards”. Maybe later today, I got up at 8:30AM and by 10:00AM it was already too hot to work outside. I fed the birds and ducked back, get it, ducked? I’m on a roll today.

Picture of the day.
In Luxembourg.
Remember to use BACK ARROW to return to blog.

           Celebrating its tenth anniversary is my DIY soldering station. Shown here, it remains the best such tool. I can partially explain. See that soldering gun in the wire holder? I’m done with sorry-ass solder irons and use this gun, which has a super-heat trigger for stubborn joints. See that auto-timer? Shuts off in ½ hour by default, can’t tell you how handy that is. The carry handle and spools are all empiracally designed on the spot. And still giving sterling performance all these years later. This has built dozens of projects, repaired cars, motorcycles, appliances, computers, instruments, and even itself.

           Some police activity over on Vine Street. I can see the roadblock from the north window. Looks like they are on a take-down, but that whole area is church people. This is why I warn people to keep off databases. Those files automatically make you a suspect over the most obscure search criteria. You can’t keep off the radar, but you can always make yourself a hard target. All bureaucracies start repressions on the easiest targets first. It makes them look like they are doing a good job.
           This is why I will soon drive 11 miles to mail my business letters and why I get my haircuts in the next town over. Just don’t be a patsy—which means don’t use the drive-thru ATM. Park your car, walk over, and use it like a regular ATM. If they want a picture of your license plate, make them ask for it.

           I threw on a DVD “Lazarus Project” thinking it would be a spy movie. Nope, it’s the old worn out theme, condemned prison isn’t really executed, he becomes part of a science project but eventually learns all his memories are real. I watched the whole thing hoping things would pick up. Still no Internet service. I used the spare time to examine Cyberlink Power Director. The trial version (usually all I need to produce good output) has some serious issues, including icons missing that are needed to operate the sofware. Boo.

Last Laugh