What do you think this circuit does?

[nomadradio]

PWM. With the drive waveform shown, it should run the lights at about half intensity more or less, without resistive losses you would see doing it the old way with dropping resistors.

Then again, in the simplicity department, wiring the two light fixtures in series would seem to achieve the same result.

Just wouldn't have the convenient low-energy on/off switch feature. And if one filament goes bad, they would both go dark.

73

 

[kopcicle]

And if one filament goes bad, they would all go dark.

FIFY
remember old school Christmas light strings ?

 

[Tallman]

PWM. With the drive waveform shown, it should run the lights at about half intensity more or less, without resistive losses you would see doing it the old way with dropping resistors.

Then again, in the simplicity department, wiring the two light fixtures in series would seem to achieve the same result.

Just wouldn't have the convenient low-energy on/off switch feature. And if one filament goes bad, they would both go dark.

73

Nope, that is not correct. The frequency of the square wave and duty cycle do not change so it is not PWM.

 

[Tallman]

FIFY
remember old school Christmas light strings ?

Yup, I remember those accursed things.
Not correct as far as the circuit functions.

 

[Handy Andy]

Considering the premise of his first post...

I won't explain how this works at least for a few days and if you are a member of a certain brain trust site please do not tell any body the how or why for this circuit.

then This post doesn't make any sense...

This is my personal invention and it was not done for any of the complicated processes you listed. I am amused that everybody just wants to over complicate the uses.

Complicated?

You mention a circuit, then have to re-post with a tiny version of the circuit we can even see...

And when I, or anyone else sees this - I answered the question from my own experiences...

We trying to answer your question with our own input...

Pretty much everyone that has responded has applied their knowledge - and now you want to call all these "suggestions" overcomplicated?

Then re-state your question - for any circuit being described here, - you should ask more of an open question about the "Purposeful application" of the circuit - not just what it does...the question IMPLIES an answer as to HOW it WORKS - not it's function for what it does...

Once you get past that...

Then you can open up for even more fun answers from - say, a handicapped successful function completed horn onto a visual aid in waking up the Newscaster when he forgets to move his head to read the proper teleprompter onto - just ignore the thread and move on...

 

[Tallman]

You are welcome to do just that. It does have an actual function, I just wanted to see how people would apply their knowledge, or over apply it as it were.

 

[543_Dallas]

Nope, that is not correct. The frequency of the square wave and duty cycle do not change so it is not PWM.

Does that 40 khz come from a photocell? Does the circuit dim or shut off the lights when they are not needed?

 

[Tallman]

Does that 40 khz come from a photocell? Does the circuit dim or shut off the lights when they are not needed?

The 40 KHz comes from a 555 timer set up as a square wave generator. Both lights function at full intensity. At 40 KHz The filaments have a thermal mass and at 40 KHz will not cool down enough to lose intensity of light out put.

 

[TM86]

The 40 KHz comes from a 555 timer set up as a square wave generator. Both lights function at full intensity. At 40 KHz The filaments have a thermal mass and at 40 KHz will not cool down enough to lose intensity of light out put.

So more or less you're taking advantage of that thermal mass to get the full light intensity at a reduced level of power consumption compared to wiring the lights directly to the 12 volt source. Which should be obvious from the fact that the drawing is labeled "power saver".

Or am I misinterpreting something?

 

[Tallman]

We have a winner! I am impressed that some body actually read the text on the schematic! Thank you! I will post the true function later today.

 

[Tallman]

The actual purpose for this design was to reduce the power draw of solid state refrigeration devices. These thermo-electric devices draw a huge amount of power until they get to their stabilized operating parameters. The power draw for the devices I was using would pull about 16 amperes per device on start up. One thermo-electric would not cause any significant amount of heat to be removed. They will be referred to as TEC from here on.
First we need to know what these devices do, they are true refrigeration devices.
Refrigeration is more than just making cool, it is the process in the way it makes cool.
Refrigeration means that coolness is made transporting heat from one location to another, swamp coolers are not refrigeration. They are using the evaporation of water to cause a drop in temperature. It is not transporting the heat so it is not a refrigeration system.
https://en.wikipedia.org/wiki/Refrigeration
When power is applied, one side of a TEC gets hot and the other get cool. Without a heatsink the device gets too hot and quits functioning all together. But when connected to a massive heatsink the cold side will quickly be covered in ice.

Now for industrial applications you need more capacity is needed than just one TEC can provide. In the time frame when we were making and selling these Switch mode power supplies did not have the power capabilities to operate the completed units.
Our first design was for a small cabinet containing a standard Windows based PC. The environment was hostile to electronics with high humidity and Corrosive Gasses.
A small four TEC has worked in this location just fine for the last 24 years needing only one fan replacement and one power supply.
The power requirements for a small 4 TEC unit was 64 amps and large linear power supplies of that power range were costing about $350.00 each and were unregulated.

Now for the mystery circuit. What it did was generate phases from DC input power.
One FET was on while the other FET off. Get the picture? The portion of the drawing has the description "Power Saver" is it's true design function. 50% power reduction.

There was a temperature control circuit that monitored the cold side temperature and would shut the power off when it was sated. The 40 KHz signal was generated by a simple 555 timer setup as a oscillator.
With the thermal mass involved the switching did not impact the performance in any way except when power up for the first time. The speed in which temperature stabilization was slightly longer, but when you can save about $150.00 per power supply it is obvious benefit is immediate.

We were able to run 8 TEC's on a power supply that use to support only 4 TEC's.
That gave us about 2400 BTU's with the same power supply.
.

 

[TheRealPorkchop]

Ok so I can see how this could relate to my refrigerated 955 but what’s my flux capacitor have to do with it?

At no point did you mention 1.21 jiggawatts, plutonium or terrorist, yet you stated not too far from the design purpose. I fail to see the correlation between your jump-starter and my time travel device. We’re all dumber for having read this very post and I award you (and me) no points.

 

[Tallman]

Instead of using 1.21 jigawatts you could use 0.605 jigawats. Also your flux capacitor has three leads power a, power b, and space neutral(Ground here on earth)
I award you 100,000.6 heckler points.
I know your flux capacitor, I sold it to you remember? I snatched it from an illegally parked UFO before they were called to tow it off. For some reason it caught fire right before the truck got there.

 

[TheRealPorkchop]

You con artist. Selling me junk.

Ok on a serious note here, the ideas listed by others, do any of those apply as uses for this circuit you’ve shown or is it only useful for what you’ve said it was designed for?

 

[543_Dallas]

My idea with the photocell may have been bas ackwards. The lights would brighten as the ambient light got brighter.

Now that the cat's out if the bag what does the writing in the schematic say? Power saver is the only thing I could make out without a 65 inch monitor.