(Dangerous mains voltages this is posted for interest only please note it is for incandescent lamps ONLY)

I used to have a clock that slowly turned a sidelamp on to simulate dawn. I had two of them in the end. This is the manual for it:

https://www.manualslib.com/products/Sunrise-System-Srs-100-10886901.html

When the second one died I discovered they weren't made any more and had been generically superseded by clocks with built in lights, which I didn't really want. And anyway, I didn't want a third one because the infernal thing buzzed at 50Hz something awful.

So I made one using a cheap USB-powered digital clock and a load of old CMOS components. I'm sure you could do all of this much better with a microcontroller, but that's what the SRS-100 did, and it meant everything was in the same box and buzzed. By having a USB-powered clock, 50Hz mains was only connected after the alarm went off. It buzzes a bit, but by then it's dawn.

I used a PWM circuit by Ton Giesberg from an old Elektor and an even older audible alarm circuit which won Tim Tanner an Electronics Today International competition in 1983 - I'd been wanting use that circuit for nearly forty years. Page 71 of https://www.worldradiohistory.com/UK/Electronics-Today-UK/80s/Electronics-Today-1983-02.pdf

I'm sure this appears to have numerous unnecessary diodes and overcomplications but it was all breadboarded over several months and it works for me. The alarm starts to increase the luminosity of an incandescent lamp over thirty minutes and then it gradually dims away. The audible alarm starts after ten minutes or so, or after nearly twenty minutes using the 'weekend' switch. The lamp is never massively bright but that suits my morning state very well. There are two push buttons, one to stop the audible alarm, and one which massively increases the rate of change of luminosity (effectively an off switch).

I've been using this for a couple of years now. The original green LED clock failed and I have a white LED one now, but the circuit still works.

 

If I were to do this today... I'd start with a Nano Arduino and work from there. But it's a nice little project and looks good. Well done.

 

If I were to do this today... I'd start with a Nano Arduino and work from there. But it's a nice little project and looks good. Well done.

Thanks Sam much appreciated - one day I'll get past flashing lights with Arduino, perhaps.

 

There has been a time delay light dimmer/light brightener in a GE HOBBY MANUAL since the late 1960's era. All of the mains voltages safely inside an aluminum enclosure, with safe controls all around. So simulating sunrise and sunset is by no means the realm of unsafe hardware. Nor is the idea new.

 

There has been a time delay light dimmer/light brightener in a GE HOBBY MANUAL since the late 1960's era. All of the mains voltages safely inside an aluminum enclosure, with safe controls all around. So simulating sunrise and sunset is by no means the realm of unsafe hardware. Nor is the idea new.

I love you and I hope you have a fantastic 2026

 

A visit to my archives found the publication: "Hobby Manual", Second edition, copyright 1965 by General Electric Company. second edition. The title of the project: "Time dependent Light Dimmer" on page 133.
Since the publication is copyrighted it may not be OK to post a scan of the article. Also, I am not sure if I can produce a usable scan from this book.

 

A visit to my archives found the publication: "Hobby Manual", Second edition, copyright 1965 by General Electric Company. second edition. The title of the project: "Time dependent Light Dimmer" on page 133.
Since the publication is copyrighted it may not be OK to post a scan of the article. Also, I am not sure if I can produce a usable scan from this book.

Viewable at page 133 here https://www.worldradiohistory.com/B... Electronics Components Hobby Manual 1965.pdf

 

OK, that is the one.The single hard to find part may be the pulse transformer to trigger the triqc. That circuit can either slowly increase the light, or slowly fade it, depending on the switch position. The circuit is not terribly complex, and there should be a brief description as to how it works.
And I am wondering what part of the world you are located in.
And please letus all know how it works out.

 

OK, that is the one.The single hard to find part may be the pulse transformer to trigger the triqc. That circuit can either slowly increase the light, or slowly fade it, depending on the switch position. The circuit is not terribly complex, and there should be a brief description as to how it works.
And I am wondering what part of the world you are located in.
And please letus all know how it works out.

Thank you MisterBill2 I found the article very interesting but I have made my circuit and it has been in use for a couple of years now. It woke me up this morning.

 

I have not seen a circuit any simpler, but a I did see a digital circuit a whole lot more complex.

 

That Tim Tanner circuit is either genius or madness – using a CMOS quad AND IC as an analog component: phew!

I'd err on the side of genius.

Round about the same time, or a bit earlier, I knocked out a (much more complex) alarm tone generator that emulated the sound of the curlew. All analog though.

 

Unfortunately, these links in the attached image return a 404.

For the Triac trigger transformer, when I was an eager but poor experimenter, I would build a suitable device from discarded ferrite AM antennas.
Cut them in 1” lengths, tightly wind the primary with 20 turns of #28AWG enamel wire. Apply a layer of kapton tape, and the again wind 20 turns of #28AWG enamel wire for the secondary.

 

Unfortunately, these links in the attached image return a 404.

For the Triac trigger transformer, when I was an eager but poor experimenter, I would build a suitable device from discarded ferrite AM antennas.
Cut them in 1” lengths, tightly wind the primary with 20 turns of #28AWG enamel wire. Apply a layer of kapton tape, and the again wind 20 turns of #28AWG enamel wire for the secondary.

View attachment 361535

I am sorry about those dud links, when I first typed up the post I had placed my photos half way through the text inadvertently, took the pictures out but the internal links remained. When I saw them I couldn't see an edit post link. I've found it now and deleted the internal links. Thanks for the tip about a trigger transformer. I might try building that circuit it's very neat.

 

That Tim Tanner circuit is either genius or madness – using a CMOS quad AND IC as an analog component: phew!

I'd err on the side of genius.

Round about the same time, or a bit earlier, I knocked out a (much more complex) alarm tone generator that emulated the sound of the curlew. All analog though.

Thank you for your reply. I think it is genius. I had a look around online but couldn't find anything else by Tim Tanner, so it seems it was his one tiny moment in the sun. The competition he won was quite a clever one. ETI gave away a free PCB on the cover which had space for one 16 pin IC and various other components. The competition was to design a circuit using the board. So you could either enter the competition or wait for the winning circuits to use somebody else's idea. That issue of ETI has so much in it.

I'd love to see your circuit for a curlew alarm. This one sounds like a kitten becoming increasingly anxious that it hasn't got a bowl of milk.

 

I'd love to see your circuit for a curlew alarm. This one sounds like a kitten becoming increasingly anxious that it hasn't got a bowl of milk.

Um... it was so long ago, and I'm not sure if I ever wrote it up, although the parts are still in the loft. The clock never reached production, as it were. Although that was 50 years ago – I'm now working on another clock, using PICaxe and Adafruit parts. But no curlew
From memory the 'curlew' alarm used at least a VCO and a ramp generator, both implemented using op amps. But there must have been more, as a curlew's call has at least three characteristics – the rising tone, the intermittent calls and the change in call rate: '[slow rising tone] wheeep wheep [fast] wheeep wheep wheeep wheep'. But today you could just download an analog track and burn it into an EEPROM or something. There's a good examle here:

 

(Dangerous mains voltages this is posted for interest only please note it is for incandescent lamps ONLY)

I used to have a clock that slowly turned a sidelamp on to simulate dawn. I had two of them in the end. This is the manual for it:

https://www.manualslib.com/products/Sunrise-System-Srs-100-10886901.html

When the second one died I discovered they weren't made any more and had been generically superseded by clocks with built in lights, which I didn't really want. And anyway, I didn't want a third one because the infernal thing buzzed at 50Hz something awful.

So I made one using a cheap USB-powered digital clock and a load of old CMOS components. I'm sure you could do all of this much better with a microcontroller, but that's what the SRS-100 did, and it meant everything was in the same box and buzzed. By having a USB-powered clock, 50Hz mains was only connected after the alarm went off. It buzzes a bit, but by then it's dawn.

I used a PWM circuit by Ton Giesberg from an old Elektor and an even older audible alarm circuit which won Tim Tanner an Electronics Today International competition in 1983 - I'd been wanting use that circuit for nearly forty years. Page 71 of https://www.worldradiohistory.com/UK/Electronics-Today-UK/80s/Electronics-Today-1983-02.pdf

I'm sure this appears to have numerous unnecessary diodes and overcomplications but it was all breadboarded over several months and it works for me. The alarm starts to increase the luminosity of an incandescent lamp over thirty minutes and then it gradually dims away. The audible alarm starts after ten minutes or so, or after nearly twenty minutes using the 'weekend' switch. The lamp is never massively bright but that suits my morning state very well. There are two push buttons, one to stop the audible alarm, and one which massively increases the rate of change of luminosity (effectively an off switch).

I've been using this for a couple of years now. The original green LED clock failed and I have a white LED one now, but the circuit still works.
View attachment 361371View attachment 361373

Very interesting, so it works, good, did you have a question?

 

Very interesting, so it works, good, did you have a question?

Thank you for your reply. No. The forum I have contributed this post to is General Electronics Chat. If I was at a real life forum for electronics I would be interested to hear what other people were up to, in case it might be something I wanted to do or adapt myself, and for general interest with like minded people. That was my impression about what forums were for.

 

Um... it was so long ago, and I'm not sure if I ever wrote it up, although the parts are still in the loft. The clock never reached production, as it were. Although that was 50 years ago – I'm now working on another clock, using PICaxe and Adafruit parts. But no curlew
From memory the 'curlew' alarm used at least a VCO and a ramp generator, both implemented using op amps. But there must have been more, as a curlew's call has at least three characteristics – the rising tone, the intermittent calls and the change in call rate: '[slow rising tone] wheeep wheep [fast] wheeep wheep wheeep wheep'. But today you could just download an analog track and burn it into an EEPROM or something. There's a good examle here:

Thank you. It's interesting that a sound that could very reasonably be used as an alarm is also arrestingly relaxing! I've now tracked down and purchased the album that those sounds are available on.

 

It's interesting that a sound that could very reasonably be used as an alarm is also arrestingly relaxing!

I think that's why I chose it. It was going to be a gift for my wife, who had a thing about curlews.

She's now my ex-wife – enough said.

 

Very interesting, so it works, good, did you have a question?

The slow speed brightener/dimmer that I suggested to the TS is a whole lot safer, and also simpler and easier. In addition it would pass the safety standards that prevail here.