Raymond (and my apologies to you for misnaming you at #36) - The one I was thinking of is Optocouplers and Fiber Optics Applications Handbook, published in 1986. Mostly it is a collection of individual ap notes, but includes other material such as articles originally published in EDN. Coincidentally, the very first thing in the book is Application Note 1002 Consideration of CTR Variations in Optocoupler Circuit Design.

Component manufacturers' ap notes can be a tremendous source for a free, if time consuming, education in electronics, especially about the "hooks" that can snag you in getting from paper designs to functioning, reliable real circuits. As your personal knowledge grows, they may be less likely to bring new understanding, but sometimes you can get a single point that makes the reading worthwhile.
(I once did an active power factor front end for a 1 kW SMPS, using a quite new Unitrode (now TI) controller. These are miserable things to cope with at the best of times. By the time I'd finished, the Unitrode ap note for the part was at revision G or H. I've never seen that many rev's for any other ap note. Ψ)

I haven't done anything out of the ordinary with conventional optocouplers for a long time. I have used some of the linear optocouplers in some industrial designs (cathodic protection power supplies/supply controllers). They're a reasonably simple solution to some serious problems and can be worth considering as an alternative to some of the very nice but rather expensive isolation amplifiers on the market.

RE: Component manufacturers' ap notes can be a tremendous source for a free - Yeah, I hear you. What amazes me is how many of these (App notes, data books, handbooks) and the like are available, regardless of date of publication.

I have nowhere near the electronics experience or expertise that you have, but I do recall being dirt-lucky when I could inherit discarded NS TTL books and the like - even the old telephone book sized DigiKey catalog had a ton of information.

That is why I went searching for that....



BTW @bertus is https://the-eye.eu/public/Books/Electronic Archive/ in your card catalog? I don't think I had ever seen it before - not terribly well organized from a searching standpoint, but seems like some material that is not on archive.org.

 

Hello,

@Raymond Genovese , The page looks like a combination of the following two:
http://www.n5dux.com/ham/files/pdf/
https://www.okdxf.eu/index.php/ke-stazeni/124-co-zde-najdete-ke-stazeni
But on the page you mention there are also a lot of databooks.

Bertus

PS I just downloaded all PDF's using the command line on the page:
wget -m -np -c -R "index.html*" "https://the-eye.eu/public/Books/Electronic Archive/"

KLAAR --2018-02-21 19:58:46--
Totaal verlopen tijd: 2h 10m 19s
Opgehaald: 3361 bestanden, 29G in 2h 2m 55s (4,06 MB/s)

 

Dear All,
Can I use circuit #24 as reported by Danko? Does it works fine? sorry I don't understand.

Thanks

 

Here is final circuit, enhanced one:

EDIT:
Circuit above is not working.
Circuit below works (transistor Q1 is inverted).

 

Ok thanks Danko,
I will test it asap, I hope, giving a feedback to forum.

Best regards

 

Dear Danko,
One question about the suggested circuit:
Do relay coil remain turned on for all the time V1 is on?

 

Yes, the relay will stay on as long as V1 is on. The short pulses sent through the optical coupler charge C2 which remains charged for longer than the time between pulses.

Les.

 

Yes, the relay will stay on as long as V1 is on. The short pulses sent through the optical coupler charge C2 which remains charged for longer than the time between pulses.
Les.

Hi Les, thank you for assistance.

Dear Danko,
One question about the suggested circuit:
Do relay coil remain turned on for all the time V1 is on?

Hello Alex,
Les already answered to your question.
About oscillator Q1...Q3. It works in simulation only. In reality it is not working.
I never believe simulator, therefore I created one more oscillator with help of brain and hands.
It was soldered and checked.
See schematic diagram and oscillograms below.
Note: transistor Q1 used in inverse mode.

 

Hi Danko,
thank you!

Do remain, on the right side of 4N35, circuit the same you have already posted, with CD40106?

 

Do remain, on the right side of 4N35, circuit the same you have already posted, with CD40106?

Right side of circuit, after 4N35, remains the same, as in my post #44.

 

Ok, thank you Danko!

With a 4N35 only, I have 0.3 mA minimum continuous current to turn on led.
With your circuit what is the current on led side?
What do you think will be the difference, in 1 hour for example?

 

With all of its electronic you will have 0,00275 mA continuous current from 5V battery.
It is 0.3 / 0.00275 = 109 times lower than with a 4N35 only.
For 1 hour you will save (0.3 - 0.00275) * 1 = 0.29725 mAh capacity of 5V battery.
Energy consumption for 1 hour with 0.3 mA equal 4.5 day and night with 0.00275 mA.

 

With all of its electronic you will have 0,00275 mA continuous current from 5V battery.
It is 0.3 / 00275 = 109 times lower than with a 4N35 only.
For 1 hour you will save (0.3 - 0.00275) * 1 = 0.29725 mAh capacity of 5V battery.
Energy consumption for 1 hour with 0.3 mA equal 4.5 day and night with 0.00275 mA.

Great!

 

@Danko has a beautiful looking circuit. The only problem is - does it work?
Regardless of which way the LED is supposed to be oriented, is there enough current to turn on the LED?

 

[URL='https://forum.allaboutcircuits.com/members/495178/']@Danko

has a beautiful looking circuit. The only problem is - does it work?
Regardless of which way the LED is supposed to be oriented, is there enough current to turn on the LED?

[/URL]
Hi MrChips,
Seems my circuit is very good IQ test.
I mean my IQ. Only full moron can to draw such absurd schematic.
Nevertheless, LED is oriented by right way, and current is (3.3V - 1V) / 33 Ohm = 0.06 A = 60 mA.
You can check it easy with help of simulator or workbench.
Or read posts #25 and #35.

 

Your circuit has a chance of working only if some timing requirements are met. That is, power must be applied in advance for a suitable duration in order to charge capacitor C1.

 

While 5V exist on left side of circuit (see schematic below), oscillator on transistors Q1, Q2 generates continuous train of pulses.
On right side of circuit, pulses continuously keep capacitor C2 charged. Relay is on.
When 5V on left side is off, then pulses are unavailable, C2 slow discharges through R7 and relay is off.
Edit: Some on/off delays (in tens milliseconds) not affect on OP purpose (I think).

 

While 5V exist on left side of circuit (see post #44 ), oscillator on transistors generates continuous train of pulses.
On right side of circuit pulses continuously keep capacitor C2 charged. Relay is on.
When 5V on left side is off, then pulses are unavailable, C2 slow discharges through R7 and relay is off.
Edit: Some on / off delays (in tens milliseconds) not affect on OP purpose (i think).

Should you be referring to post 48, instead of 44? I thought you said the original circuit from your post 44 simulation didn't work, but that you physically built the oscillator in post 48 and that one did work.

 

Should you be referring to post 48, instead of 44? I thought you said the original circuit from your post 44 simulation didn't work, but that you physically built the oscillator in post 48 and that one did work.

Good remark. I will draw working full schematic and place it to post instead of #44 link.

 

Dear Alex1965,
You know already about delay between On/Off 5V and On/Off relay, relatively, from posts #24 (simulated diagram), #30 (LesJones said: I think your circuit should do what the TS wants. I don't think the 30 or so mS delay should matter.), #36 (ebp said: His circuit would work very well for the TS's requirement where the longish time delay is of no consequence.).
Now, in post #56 MrChips said: Your circuit has a chance of working only if some timing requirements are met.

So, now you can decide: To use, or not to use...

Danko