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A momentary normally open push button to close and latch the relay
A momentary normally closed push button wired is series with the coil winding to release.
Bertho

I had to go and dig for JK schematic. I have always (way back when) used NAnd gates to create. Did not know there were JK ff ic packages. Maybe I did, and just used NAnd as the lab from TI missile systems was very generous with NAnd, NOr as well as XNAnd and XNOr. No guidance chips however :(

Do have a bunch of old Spartan FPGAs. Definitely do NOT remember how to program those, besides software was on the 486. I have backup media somewhere... on floppies.

I actually found a pic of my notes (d. cameras still new and rare). Amongst other scribbling (regarding questionable parental lineage of the class instructor) was the line:


(2) 3input NAnd (2 j/k, 3 clock, 1(k) ties to output, 1(j) ties to comp output. Each Gate output ties to 2 input NAnd, whose 2nd input ties to other output.


I don't remember use or provision for set / reset lines. But, looking at ic packages, there are preset and clear. I think these might be the first inputs of 3 input NAnd that are connected to complimentary outputs.

It seems that every 'off the shelf' latch relay I looked at had some sort of 2/4/8 bit microprocessor, or intended to be tied to arduino/raspberry pi/etc.

Plan was to use NAnds to create my FF, input denounced using Schmidt trigger after a 300mS or so delay. So far, actual chip count is 4 for single relay: (1) 3ip NAnd, (1) 2ip NAnd, Schmidt Trigger, and the 2038. 2ndcrelay would need another asst of NAnds. Plus inverter so have active low on strobe to improve noise immunity. Drivers / Latches were intended to be in seperate housing than relays.

~SD

On Saturday 30 November 2024 04:42:30 pm paul larner via groups.io wrote:

well i orderd one along with some esp32 blue pill boards to make a coil winder with,will see when they get here,aliexpress say delivery should be on dec 5th.

Oh, that ESP32 is a fun one. LOTS of capabilities there. Check out the youtube videos by Ralph S. Bacon (who unfortunately hasn't uploaded anything recently, I hope he's okay). He does a number of them that deal with that part...

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

On Saturday 30 November 2024 04:29:03 pm paul larner via groups.io wrote:

the main voltage pot is a 1k with just the center and one outer leg used,

In a situation like this, it's really best to tie the unused leg to the center one. The reason for this is if there's any intermittent contact, the effective resistance goes from wherever it's set to effectively an open circuit, where if you have the unused end tied to the center then an intermittent contact will at worst give you maximum resistance. This goes for trimpots, too. It's common practice, or should be.

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

On Saturday 30 November 2024 03:51:56 pm Roy J. Tellason, Sr. via groups.io wrote:

I have some radio shack packages with "IR emitter-detector pair" in them, ?and an assortment of phototransistors pulled from scrapping VCRS (there's at least two in every VHS machine) and some other parts salvaged from floppy drives, ?where they are used for write protect and index hole sensing. ?I haven't found any particular use for these parts, ?maybe I just haven't found the right inspiration yet...

Oh yeah, and optoisolators and optointerrupters. I have a whole tube of NOS 4N26, I think, plus piles of salvaged other numbers I did find a use for an optointerrupter. I was given a sewing machine motor, plugged it in and spitzensparken! So I disassembled it and replaced the cord. Then with it spinning I wondered how fast that thing was going. So I rigged up an optointerrupter on a bit of perfboard, put a bit of tape on the motor shaft, and coupled the output to my scope. It was a surprisingly high number as I recall, though of course there was no load on the motor...

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

On Saturday 30 November 2024 09:52:11 am Terry wrote:

BTW, (an aside) the "D" latch becomes a mono stable "flip-flop" when /Q output is
tied to the "D" input and clock cycled.

No, that's bistable.

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

paul larner <quadzillatech@...> added the photo album my psu : my psu pics

On Saturday 30 November 2024 07:52:01 am Andy via groups.io wrote:

Important points being that outputs are low upon turn on, ...

I think not.? Most if not all flip-flops come up in a random state when powered-up.? (Chances are they have a bias for one or the other, but that is not a design feature and should not be counted on.)

A point that I didn't address in my earlier reply. You've gotta do *something* with those set and reset pins. A power on reset signal would probably be a good thing to add to your design. That can be as simple as a resistor and a cap tied to the input of any schmitt-trigger gate's input, the output driving the reset line.

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

On Saturday 30 November 2024 07:17:08 am Bertho wrote:

It is not what you asked for, but if your relay has extra contacts you can wire it up to be latching and releasing with a separate line.

I can see how easy it would be to make a relay latch, but how would you get it to release?


--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

On Saturday 30 November 2024 02:49:34 am Bob Smith via groups.io wrote:

On 11/29/24 22:36, SheldonD via groups.io wrote:

Reaching way back in my mind, I seem to remember JK flip flops toggling output when strobed

So not SET and RESET lines but a single TOGGLE line?

That is tricky since you may get ringing or noise on
the line. Use separate lines if possible.

That's why he specified "debounced"...

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

On Saturday 30 November 2024 01:36:13 am SheldonD via groups.io wrote:

Been playing with various chinese-originated latching relay solutions from Amazon. Most are 'overly optimistic' about capabilities. Very 'overly optimistic'. Otherwise the rest have issues operating in environment with heavy canbus, Bluetooth, pwm alternator, 2M xceiver, and brushed engine / HVAC fans.

Reaching way back in my mind, I seem to remember JK flip flops toggling output when strobed if J&K are tied high. Maybe it wasn't JK, but another type? Important points being that outputs are low upon turn on, and stroking with momentary (debounced) switch (high input).

That'll work, also a Type D FF, if you tie the D input to the Not-Q output. Whether high input will trigger it or not depends on the part, they can work either way, check the datasheet (have a look at rtellason.com/ic-generic).

I am thinking that can tie outputs to darlington driver array, like ULN2803 or similar. Up to 1/2A current, 50vdc max, designed for inductive loads. Haven't found any information on temperature control yet.

Not sure if I am reinventing the wheel. I do know that relays / contractors that utilize magnets for latch hold are probitive physically and way overkill.

Yeah. Just adding a bit of electronics is way cheaper/simpler overall.

Incidentally, relay outputs will be controlling multiple isolated power supplies. Need around 16ch of mixed outputs.

Suggestions or alternatives if I am on wrong path?

Tomorrow I will be trying to find 32/64 bit versions of LTSpice (or similar) as my 486DX4 based PC (500MB drive and 8MB Ram!) 16/32bit machine died during Hurricane Beryl.

Stuff like that oughta be easy to find, and dirt cheap. Most of that vintage stuff like that that I had is in boxes out in the garage, destined for the recycler. I was actually using a 386 box for a router/firewall, but found that a dedicated router was a *lot* faster in terms of throughput, and that on a DSL line!

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

On Friday 29 November 2024 07:35:28 pm wn4isx via groups.io wrote:

We've had several requests over the last few years for LED flashers for model train enthusiasts. One problem with most LED flashers is the go from full off to full on whereas old style caboose, water tower, and crossing gate lights were incandescent and ramped up and down.

If you look at brake lights on cars in traffic it is easy to see this effect, the LED brake lights come on instantly and the incandescent ramp up when turned on and down when turned off.

I have no idea what degree of realism model train types want or can achieve.

I remember with my model trains as a child I was unhappy with the 'acceleration curve,' you went from standstill to ~20MPH. And yes I know there are better controllers today.



There is a short MOV you can download to see if the effect is what you want.

[I stumbled on this by accident and can offer no advice.]

ff you want to see a bunch of nifty model railroad electronics look up Rob Paisley. I stubled across his pages some time ago, and enjoyed browsing through them.

For flashing LEDs on a layout I'd just go with a simple astable, four resistors, two caps, two transistors and you're all set. It should be possible to make things ramp, I'd guess. Maybe by using relatively large capacitors?

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

On Friday 29 November 2024 07:24:12 pm wn4isx via groups.io wrote:

This will be my last post on non-LED semiconductors emitting light.

First, all of the forward biased semiconductors I tested emitted light. The glass cased silicon diodes were the easiest to verify, I chopped the tops of several TO-3 and TO-5 transistors. All of the emitted light required a night vision (starlight) scope to see. 4th vision nightvision scopes have between 25,000-110,000 gain, the exact gain figures are apparantly restricted by ITAR [International Traffic in Arms Regulations].

However reverse biased semiconductor junctions are a different story. I'll admit I was pleasantly surprised....

A friend gave me this link. Interesting to be sure but I doubt it's practical.



And it might be worthwhile to follow the links here



This image is fascinating and I was able to come very close image with a 1980s 2N2222 with the top removed.



This light is clearly visible in a dark room.

I sacrificed 3 2N3055s. These were older RCA units with excessive leakage.

All 3 emitted nice light when the collector to base junction was reverse biased to break down.

Note: Limit breakdown current to a few mA.

This has been an interesting, if relatively useless experiment.

I remember bumping into something weird in certain Yamaha power amplifiers. They used an actual LED as a biasing part. Though this was not in the typical LED case, but more like the sort of glass-bodied case you'd see for a 1N400x rectifier or similar. I'm not sure why they chose this part, not having actually sat and analyzed the circuit, maybe temperature coefficient or something?

I know that there were a whole lot of power amps out there that when one output device failed, the rest of them, along with the drivers, and someimes a whole lot more would also fail. This was not the case with those Yamaha amps, you'd blow one device that that was the extent of the failure, pretty solid stuff that was.

Another thing that comes to mind is a thing that Forest Mims did one time. He had two LEDs facing each other, and the one that lit would cause the other one to act as a photodiode.

I have some radio shack packages with "IR emitter-detector pair" in them, and an assortment of phototransistors pulled from scrapping VCRS (there's at least two in every VHS machine) and some other parts salvaged from floppy drives, where they are used for write protect and index hole sensing. I haven't found any particular use for these parts, maybe I just haven't found the right inspiration yet...

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin