I did not expect this thread to blow up like it did. however I appreciate that it did. Lots of circuits and ideas to try. within the coming weeks I will likely have all the parts around to try at least one method. I would like to try them all tbh..

I am not super fond of the resistor idea anymore due to power waste/inefficiency

however I could build that too and see what happens I suppose. This is a separate project but eventually I want to also try and make a slow ramp up circuit for the halogens to prevent such a hard toll on the alternator when all that wattage comes on at once.

I am assuming I can make something utilizing a MOSFET, and a capacitor charging slowly via a resistor. I will have to mess around with that at some point. I don't want to mess with micro controllers if I don't have too mostly because coding is not my strong suite...I suppose better time than any to figure it out. But I do like the idea of simple "Dumb" circuits. It is what I grew up messing with and where my (limited) knowledge actually resides.

UPDATE:

The circuit for that specific function was actually pretty easy to find. Seems this one ramps up at 500 µs which seems quite fast for a halogen. So I probably will need to modify it/ look around more but the idea exists out there in the hobbyist space which is good.

https://www.instructables.com/Soft-Start-and-Soft-Finish-for-P-Channel-MOSFETs/

Common practice for rural intersections here is to use one or two cobraheads at opposing corners and then add a spanwire flashing 4 way beacon if it requires extra attention. It works but I suppose it costs more than a single spanwire light.

Spanwire LED bucket lights, especially in 4000K or 5000K sound terrible. Bucket lights have no optical control and they probably should have used a spanwire gumball instead if they wanted to keep the spanwire.

Some intersections don't quite need a flashy light but may need some other indication of their existence. in my experience the flashers also are blinding at times because most of them lack any form of photo control to dim them down at night. the yellow LED flashers are blinding for no reason. An illuminated box sign would serve nicely. or just a standard FCO street light on a pole. or an FCO spanwire mounted at the correct height to prevent glare through the windshield.

I have seen some of the HPS span-wires in Michigan and YES , they DO suck !  There's even some of the LED versions on the freeway at the entrance/exit to rest areas !

I love HPS and wish I could say they worked well in span wires. but 50 watts is too dim for an orange street light. and 150 watts is a glare bomb. not nearly as bad as the LEDs but they just don't belong in bucket optics in the center of roads mounted at the height they usually are. they at least function OKAYish in dry conditions and they are okay in small towns where they are strung really close together. LED is just JUNK. crappy beam pattern and complete light wall right in the center of the road during rain/snow/fog. it is honestly dangerously terrible. they need to be removed.

bucket style span wire died with Mercury and lower wattage sodium. time to move on to FCO stuff.

So what is your opinion?

Fog lights + Low beams

OR

Fog lights only?


My truck is wired in a way that allows the main headlights to be turned off while the fog lights still operate with the parking lights. When I turn off the low beams and fog and ONLY use the fog lights. Visibility of the road and tree line improves. My friend argues that it is against the law to do such things. however I hear over in Europe in heavy fog, it is common practice to run only the front fogs+parking lights+ rear fog with main beams off.

What is your opinion?

After the fall of communism, during which the basic necessities of life were available for essentially everyone at a very basic level, the economy completely collapsed for about 10 years. People literally had to scavenge for anything sellable to be able to survive. Tons of people went unemployed because the inefficient big industrial kombinats were unable to compete with the much more modern western companies, when suddenly they have to pay market price for their raw materials.
State pensions for elderly people who worked all their life evaporated overnight. People's welfare, income and life style literally dropped from 'Poor but never in fear of going homeless or without a full stomach' to 'the worst 3rd world country you can imagine' in the span of 1 or 2 years. The Soviet Union was bankrupt well before that of course, change or collapse was inevitable.

This was all presented under the guise of 'Economic shock therapy'. Obviously this 'shock therapy' was stupid, Vietnam and China proved that it is perfectly possible to open up the market to private enterprise and foreign capitalist investment in a much more gradual way. Unemployment was also a problem in east germany, but the stripping of materials wasn't nearly as bad.

All of this to paint a picture of the truly unprecedented change in living conditions that the former soviet union went through. I think it took about 10 to 15 years for things to stabilize a bit, but people who are more specialized in that part might be able to tell more about that.

Every single thing that contains valuable metals or is valuable in itself, that was not piled up in radioactive waste dumps, was stripped out of the exclusion zone by scavengers, since the apartment blocks and many streets could not all be guarded by guards to prevent looting and stripping. They were almost all conveniently empty. Elevator motors were stripped from their copper wire right in the lift hoist room. Poverty was so extreme that people were willing to risk contamination and punishment going into the exclusion zone. You cannot easily steal a ferris wheel or some bumper cars (that stuff is quite large and is mostly steel rather than the more valuable copper or brass) but you can rip out power buses from fuse boards and wire from large motors and carry it back home in your backpack. Driving a car into the exclusion zone would stick out like a sore thumb. Perhaps some people would bribe the (equally poor) guards and be able to sneak in that way.

Only a handful of buildings were kept in good shape for the people who work at the power plant (which was kept going for quite some time - the power plant wasn't closed after the disaster!) so if you stayed away from that area you could loot what you wanted.

This stripping was not just confined to Pripyat either - it essentially happened in every area where factories closed and people went unemployed. But in Pripyat it's most obvious because it was literally an almost empty reasonably sized city.

The spooky thing is, where did it all go?, Pripyat being so hurriedly evacuated in 1986, doesn’t really explain where the infrastructure went, including the road in the comparison photo?, unless it’s under all that mud🤔, but the traffic signal? What happened to that?
The ferris wheel remains to this day, as you see on so many photos, but other metal structures such as the above traffic signal pole completely disappears?🤔

Driving everything with the comparator outputs directly would mean connecting everything to the same point. With open collector comparators this is definitely a problem, as the intermediate voltage on the dividers etc will appear on the gates of the MOSFETs that shut down signals. To make this work at all, voltages of the dividers would have to be carefully considered vs. the MOSFETs Vgs th.... More design constraints and worse reliability

With push/pull comparators this could work, but i dont see a justification

Small signal MOSFETs are cheap, use them to break up everything to separate lines and invert as necessary, each with its own simple design requirement, resulting in fewer constraints and compromises in the design

Obviously I meant combine that way those that lead to the same response - like overvoltage, undervoltage and thermal shut down.
The extra transistors may be cheap, but it still means extra components to deal with. Plus discrete MOSFETs seems to me rather sensitive devices to handle, way moer than even the complex LSI CMOS IC's use to be. Apparently the desire to maintain the process simple and cheap does not allow any decent ESD protection on the gate. And compare to the power elements, they are lacking the high gate capacitance the power devices inherently have, which allow the large devices to swallow quite some charge without reaching any dangerously high voltages.

 - EOL lamp only prevent the 50% opreation - Full power with the remaining lamp is still allowed. So it shut down the switching generator IC only

Well, the other protections (OV, UV, TSD,...) still need to remain active and effective, even when in this "open lamp" mode.
For that I would make the open load detector to just stop the oscillator when the VDS at switched off transistor remains low. That way it keeps the other side full power, but still allow automatic recovery once the fault is fixed (= the lamp being replaced).
And because it goes via the chip in a normal way, other protections are working the normal way.

@James
Oh okay, so just sharpened graphite rods. I knew tools like this were used in scientific glassblowing and the like but I didn't know they had a name.

Thanks again

I mis-typed the alloy : it is actually Elmedur X.

Graphite pencils, Are basically just thick rods of high density graphite.  Like a pencil but without the wood, and no clay or binder in the graphite.  They are useful in diameters from about 5-10mm.

Okay, the devil is in the details. Skyworks does not appear to to be overly honest on which parts are certified for which purpose in their datasheet. Well, even Chinese friends put it more clearly! For QSOP part the isolation rating is very minuscule (down to 1kV!) so it will not qualify and will be plain dangerous even for basic insulation, which requires a mandatory ground connection anyway.

We of course are using wide-SOIC reinforced 5kV class chips for anything between live and low-voltage circuits, SO8  for functional insulation only.

Still, you are right that digital insulators are at somewhat elevated risk of getting shot-through on a several abuse. TI even has a special application note on this.

That isolator was Si8641, rated as basic insulation (it was in a SSOP package. The same component in a SOIC-W would be rated as reinforced insulation). It was burned internally without visible external damage. Showed some medium resistance on a megger between the sides

(And dead short between VDD and GND on the side that was burned out, but this can be expected)



For your resistor suggestion :

Connect the resistor from the minus side, and route the lamp wires such that they cannot short to each other (so the wires come right up to the lamp holder from 2 sides, and not in one cable). This will reduce significantly the chance of full 12V getting to the resistor

Protect the circuit by a motor overload breaker set to the precise current - like PKZM0-25 or similar

For the resistor construction :

 - As the resistor element use a packaging steel strip. Use the thinnest possible so it have high resistance/unit length. The element will be of large length (about 4m if folded by two in a 2m long duct)

 - The resistor is installed on busbar insulators.

 - Cable duct made of metal with ventilation slots as the outer housing. Install a unit of ~2m length (as much as can fit) under the car

It may be possible to fit 2x or 4x the resistor element running in parallel along the duct. The 4x configuration is the best here, as it allows to fit 2x 4m long resistors (so the resistors for both lamps) in a single 2m long duct

The heat dissipation <100W in a 2m long metal duct is not much, it is not going to get to any high temperatures