I’m old enough to remember roadworks beacons that used a paraffin lamp. They went electric around 1966.

@bigclivedotcom

2 ай бұрын

Those used to be really cheap on eBay, and now they are expensive vintage items.

@alunjones3860

2 ай бұрын

Did they originally use a bulb with a bimetallic strip for the flasher?

@kwakamonkey

2 ай бұрын

They were still using the paraffin ones in the 1980s where I lived .

@belyear

2 ай бұрын

@@kwakamonkeyI saw them in the Eighties too.

@TheRealBobHickman

2 ай бұрын

Came here to say this too. I used to see those regularly in the early to mid 70s. There are a few variations on the classic lantern battery ones too, like the one with a rectangular body and a huge round lamp/reflector that had an on/off switch accessed though a pinhole in the body.

very few youtube channels would be able to make reverse engineering a blinking light as interesting as you do

I remember having several of the American style ones when I was a kid in about 4th ot 5th grade back in the very early 80's. I was walking home from school one day, and the main road that took me home had been under construction ALL summer long. I'd make my way thru the job-site everyday, and check out the progress as I walked home. That day I found a box along side the new curb with about 7 or 8 of the flashing lights in them, and they looked to be broken up or not working. I asked one of the workers in the orange vest if they were garbage, and to my delight he said YES! I dragged the box home, and was able to take them all apart and make a few good ones out of the bunch. They even came with 2 6-volt lantern batteries in each one, and many of them were still good. I put the ones that I got working all over my room, and my favorite part of the day that summer was dust, when they'd all magically turn on and my bedroom would be flashing orange all over. I was amazed that the 2× 6-volt cells in them would keep them running all summer long. I kept those things for YEARS.. later on, I put brighter incan bulbs in them, and finally some yellow LEDs when some bright ones finally came along. I learned how the circuit worked way back when, and it is a fond memory of one of my first forays into electronics as a young boy. 👍

In the 80's our council/highways used lams that took two lantern batts in parallel. As kids we used to wait for the roadment to go home, after loading new batts into the lamps. And go and swap one out for a flat batt. A great source of batteries as a devious budding engineer.

Can you imagine how they secure construction sites along roads in Brazil over night? Every few meters is a red 10 l plastic water bucket, upside down, in an altitude of 1 m (3 ft.) above the road. They stuff a 100 W bulb below/inside the bucket. That gives the most beautuful large red light that you can see from far away. Below the bucket is a cone of white light where you can see imperfections of the surface and debris without blinding your eyes. Genius. Cheap. Perfect! 😃👍

When I was a youngster, I had one of these. It used a nail to pass through the case to click an on /off switch. Memories from over 60 years ago 😊

@nomusicrc

2 ай бұрын

I had the American version of this I also had to stick something to the hole to turn it on and off mine was more of a flat flashing construction light I think it took one 6 volt maybe two I wonder what happened to it

@GlutenEruption

2 ай бұрын

@@nomusicrc same here. They were doing roadwork in front of my grandparents house and when they left for lunch, grandpa just yanked one off the barrier and came sauntering in with it so I could take it apart 😂😂. Those were the days.

@nomusicrc

2 ай бұрын

@@GlutenEruption I might have borrowed mine too

@pavierthermostat8763

2 ай бұрын

One of these manifested itself in my living room the morning after a night out in Kirkcaldy 😂 … Mine had a flasher bulb and no pcb, with a push on-off switch behind a hole. Probably sometime in the mid 90s.

@hatake_kakashi7359

2 ай бұрын

This comment was made 7 days ago?

I used to get these as a kid - no circuit board at all - just a bulb that had a built in flash mechanism

@teardowndan5364

2 ай бұрын

Just like those xmas string lights where one bulb on the whole string is a flashing variant, usually a clear glass bulb with red tip for easy identification. Apply ~3V and it flashes on its own.

@ashleysmith3106

2 ай бұрын

@@teardowndan5364Bi-metallic strip.

I remember taking one of those roadwork signs apart when i was a kid. I had taken it because it was not flashing like all the others and figured I'd try to fix it. I learned that the flashing was controlled using the DCF77 signal (which I had done a project about in school) so the 0-9 selector in the bottom simply controlled which 1/10 second it would flash so multiple could be synced up without wires. Long story short, I managed to fix it and put it back so the light sequence was now complete. 😀

A former colleague of mine was involved in designing the empco barrier light - the sort with a Fresnel lens front and back and which have a very brief flash. It was discovered that the brief flash was good at attracting attention and required a much lower mean current. The bulb was very overdriven for the brief flash which improved the efficiency further and gave acceptable bulb life because of the low duty cycle.

Confession: I used to "secretly permanently borrow" those blinky barricade lights back in the 80s. I don't know why (oh we all know why, because free battery-powered blinky light!! Plus a side of "I meant to do it but didn't mean to get caught"...). I had 5 at most and let a friend have one, which he had an attic bedroom and put it in his window LOL. I lost them during one of my too many moves in my dumb/broke/young-adult days 😒

@galdavonalgerri2101

2 ай бұрын

I remember "permanently borrow" something also, I just called it "finding something before the other person has lost it"

Oh the memories. Swiped a lollipop style one of these as a kid and tore it apart. The things you can do with a 6v battery and a piece of wire as a devious child. Not to mention the free flashlight bulb LOL

@volvo09

2 ай бұрын

The lollipop style ones are all I would see in the US. I wanted one as a kid, but could never snatch a loose one.

@Sonny_McMacsson

2 ай бұрын

The 6V lantern batteries were good to waste on making pencil leads glow.

@Woffy.

2 ай бұрын

The road workers always had spare bat's for a lad to play with. The early ones had a bimetallic switch in the bulb so when the bat got low they would just stay on.

@johnnodge4327

2 ай бұрын

​@@Woffy. They did indeed. No electronics, just a flashing bulb. We used to "borrow them" and salvage the batteries for other more interesting uses.

@Woffy.

2 ай бұрын

The cells if I remember were like D cells but longer later replaced by stacks of AA's. @@johnnodge4327

I noticed that the modern versions of these can flash in sequence with the one next to them in a row which seems pretty clever. My dad came into possession of an oil road light back in the day.

@guydouglas8212

Ай бұрын

would love to see how they work

I cracked open a 6v battery when I was young and discovered that there were D size batteries inside...pretty neat discovery when you're a kid :)

@m.k.8158

2 ай бұрын

Actually, the standard cells in the type of 6 volt battery Clive showed were originally "F" cells...however, the modern ones may indeed have "D" cells with a spacer added to take up the extra space.

@volvo09

2 ай бұрын

​@@m.k.8158 yeah the old ones had D width cells that were as tall as the case.

@georgescott6967

2 ай бұрын

Did you then pull the cell apart? A nifty carbon rod down the middle surrounded by black goo in a zinc case.

@Roy_Tellason

2 ай бұрын

The black goo being mostly manganese dioxide with some ammonium chloride in it. Handy for chemistry experiements;.

@thomaswilliams2273

2 ай бұрын

You can tell whether it's using Ds or Fs by finding the balance point of the battery.

My grandfather worked on the roads and gave me one of these when I was a kid in the 80's. My one had no light sensor. You had to twist the top so it made contact with the battery.

@volvo09

2 ай бұрын

I always wanted one as a kid, I loved lights and batteries.

nicked a few of these as a kid, the batteries were so useful.

@luminousfractal420

2 ай бұрын

Caught a look into some guys back garden the other day. He had 3 36" solar panels he'd robbed from the roadworks. Going green but not straight 😂

I'd like to see a teardown of the motorway ones that synchronise to give a travelling pulse down a long line of lights on a barrier. It's always intrigued me how they work.

"The reason the light is round is because roadworkers often smear the lights with grease and then sit on them for manly pleasurement, although that may not be factually correct, since they actually use cucumbers or Temu insertables instead. (Hardly anyone reads down this far anyway.)" ROFLOL 🙂 Even if I don't watch the whole video, I always read your description because your descriptions are always so thoughtful and spot on. Most youtubers don't even fricken bother with a simple description. )-: YOUR'RE THE BEST BIG GUY!

When I was 13 or 14 I had a chance to try to repair neon flashing traffic lights at my Dad's construction company. The "flashers" replaced kerosene lanterns (circa 1950s). I was shocked several time as the electric flywheel made then broke the inductor circuit to get high enough voltage to fire the lamp. I learned the circuit operation by going to the city library. It was like a car ignition circuit. I was then the guy who fixed Dad's flashers. Part of reason I became an engineer.

Ah the memories of "taking" them from roadworks and then using them at home for a cheap rave, happy days

The more professional flat type used to have the flasher encased into a block of wax. There was a small hole in the side to access a push on/push off switch with a match stick. I often used to "find" these as a kid and take them apart.

@dcallan812

2 ай бұрын

It was surprising jhow many you could find just laid about 😃 I had a few I took to bits and had disco in my room. 👍👍

@TheChipmunk2008

2 ай бұрын

I have one of the cone top ones rescued from a ditch after some roadworks. The switch mech is very clever, it has the 6v battery in a 'backpack' type dealy thing, a very bright amber LED , and putting it over a cone closes the contacts. all made of folded plastic

As a kid I was fascinated with flashlights/torches. I always wanted to add one of these to my collection but never got up the nerve to nick one.

The Pre LED USA barricade flashing lights differ in 1 main way, the flashing circuit is supper brief and the lamp is rated at a lower voltage that the 6-volt battery. So, the lamp acks like a strobe. They hit the low voltage lamp for a brief pulse for a super bright flash that does not burn the lamp out.

Ive been told from people who used to borrow those types of lights in the 80s that some of them had a 555 timer and a transistor to control the flashing.

Hi Clive, I had a lollipop version of this lamp as a teenager. These things are almost disposable, (they’re used by the thousand and often hit by passing vehicles) so even saving the cost of one resistor and its assembly cost mounts up. That’s why this is so minimalist. The one I had did have an LDR built in, and that was to synchronise the flash to the next one along the road so the net effect was a strobe sequence along a feed-in where a lane is discontinued. Presumably the response of a simple LDR is not instantaneous, hence the slight delay in each lamp flash producing a progressive animation along the row of lamps. I imagine there were build options with and without the sync LDR. Very few components producing a sophisticated multi-lamp behaviour.

The ones I remember from my childhood was the big metal square ones with the lens in the middle. Later on they went to the plastic ones with the large lollipop style lens on top. I always used to like it when a group of these would get in sync with each other for a bit xD

Ahh, yeah, I remember those lamps in the early 80s, they used to to attach to the top of a yellow metal tripod with that screw using a triangular key. We had to walk the entire line of roadworks turning them all on before we went home in the evenings. If they didn't turn on you'd have to swap for one of the spares carried threaded on a rope through the wire handles. These were the first move towards the modern traffic management. How times change, the only hint of hi vis clothing was having orange shoulders on your donkey jacket. Welfare was an aluminium shed with bench seats inside and a gas ring to brew up. Despite safety being more basic, working on the roads was safer back then, motorists weren't as ignorant, impatient or distracted as they are today.

@bigclivedotcom

2 ай бұрын

I still have my donkey jacket from the past.

I remember having a Pifco lantern in the 1980's that had a forward pointing torch and a red flashing top light that worked off the same lantern battery as yours. However the bulb had an integral tiny bi-metallic strip to make it flash. They were small screw in bulbs that had a sort of dimpled pattern spherical glass that was quite a bit larger than the threaded body.. I love how you make everything so interesting.

I love the colour bands in the resistors. No idea why but I've always found them to be very aesthetically pleasing. They almost look hand painted.

I'd love if you did more videos of cool stuff like this that the general public can't get!

I was expecting a two transistor multivibrator/flip-flop circuit. Remember stealing one of these units as a child 😂, and playing with it for hours 😊

As Kids some 40+ years ago, we used to nick the battery's out of them for our home electrical needs. (Basically the light in our tree house). the flat round type had 6 volt bulbs with bimetallic strip in it, so no circuitry needed.

Transistorised flashing circuit. I have a few of these including a blue one with a strobe. Takes a 6v battery 4R25 or in old code Ever Ready PJ 996. In the old days Ever Ready did road lamp batteries for industrial use only. British gas did there own battery made by Ever Ready. Some of the early ones did use oil. The earlier electric ones used a split filament bulb for the flasher part, no transistors. I have a few old Pifco lamps that used these bulbs. I have a lamp from Eveready of the same age that's American and made by union carbide that has a transistor flash circuit. Once again Clive and excellent video.

had never seen this sort of beacon well done

I too had the American version of this thing back in the 1970s. Got mine at a thrift store. It used a thermal switch “bulb”, no other components. The on off switch was two brass strips inside, operated by what looked like a bolt head. Took me a while to figure it out, it was so simple, but everything didn’t line up when it was opened, so I had to do some mental gymnastics to figure out where everything would be when it was assembled. In yours, the lamp turns on when initially powered up because the capacitor looks like a dead short so the resistor divider turns the left hand transistor on hard, turning the other one on. Thereafter it operates as you said, the capacitor charging through the 200K resistor and the transistor’s b-e junction until the transistor can’t stay on etc. The cap appears to discharge through the battery. The connection across the cap is puzzling indeed. I mentally ran through various components that might be attached there and what they would do. A resistor would, as you found, just make the lamp stay on. A capacitor would change the flash rate. A switch again would make it stay on in one position and allow it to flash in the other. I think that might be the intended function for a different model that had the included switch. I can’t quite figure out how the marking on the board relates to that though. Thanks for the blast from the past. Brought back memories of learning troubleshooting on very non-standard gear. I hope someday you get hold of an old rotary phone and explore the balancing network that permits duplex operation without echoing . Those things are black magic, full of inductors, resistors and capacitors with weird values you won’t see anywhere else.

@wtmayhew

2 ай бұрын

There’s a great article in the Bell System Technical Journal (BSTJ) from about 1953 which describes the Western Electric model 2500 telephone which was a staple of telephony through the early 2000s. The hybrid network is a model 425A. It works sort of like a Wheatstone bridge so that the carbon microphone current and the line current oppose each other in the transformer and cancel out in the ear piece. With no microphone current, the line current is unopposed and thus is heard. The 425A network contains several varistors which essentially program the microphone gain and ear piece sensitivity to compensate for the varying length of the subscriber loop. It is an excellent feat of analog engineering. The Bell System Technical Journal is archived on line.

@eDoc2020

Ай бұрын

@@wtmayhew I'm sure that 1953 article wasn't talking about the 2500 because Touch-Tone wasn't introduced until 1963*. The article was most likely detailing the regular 500 rotary phone. Although I believe the 2500 used the same hybrid. *The rare 1500 was used in 1963, the 12-button 2500 was 1968.

@wtmayhew

Ай бұрын

@@eDoc2020 Thank you for the correction. That was a typographical error, should have been 500. The correct network model number is C4A 425 (which was revised several times to at least 425E). I have a 233 3-slot pay station which I use with a 685A subset box which contains a ringer and a 425E network. I also have a later 236 single slot pay station which has an internal network labeled 4010B with a C4A single gong ringer mounted on it. The station service/coin serve manual I have doesn’t go into detail about the internals, just has wiring diagrams. For the record, 453A is a vacuum tube which does not apply here,

seems like most of the people in the comments remember swiping one of these as a kid. Orange flashing bedroom lights are cool!

The old "996" batteries were the standard for the lights used by the Night Shift nursing staff back in the day! The "standard NHS contract" Ward Torches seemed to always be the Ever Ready "Dolphin" brand. Nowadays our Night Staff use rechargeable LED lights, which are brighter, lighter and far more reliable.

That's a really aesthetically pleasing design for such beacon, here in italy both the small and bigger version are square and not as nice looking. That said I have a yellow one in my collection of lamps. The lantern battery are extremely easy to restuff with lithium cells and charging circuitry, the pain is to empty and clean them up when the original cells are all swollen and corroded

Would be an interesting vid if you made a new circuit board for that from scratch, showing the values and improvements!

I pulled one of these apart.. many many years ago, and didn't even have the transistor switcher. The flashing was the bulb itself, it was similar in construction to old christmas tree lights, with a bimetallic strip. The bulb would heat up, strip would open, and then it would close again. They also had a fun side effect of spending less time on in the heat/day.

I took one apart in the late 70's (a college thing). The flash was short, like a pulse. I reverese engineered it and found a two transistor relaxation oscillater with a tantulum capacitor. The board was thin and contained inside a plastic tube, with the bulb on the end. I think it charged the capacitor and then dumped it through the bulb. It lasted ages on one of those batteries.

I still have either 2 or 3 of the paraffin ones those replaced in the shed, bought somewhere or other new for dirt cheap. They've never been used for lighting, though they have seen service as low level greenhouse heating.

I remember them having no circuitry and only a flashing bulb inside. A thermal strip creating the flash inside the bulb. Today, when I drive the motorways at night, I see roadside beacons that appear to 'talk' to each other and create pulses of light showing the path of travel to drive.

Amazing tungsten roadwork 🚧 beacon

I still have one they used here in Australia in the 70's to maybe early 90's. It uses 2× of those big 6V Dolphin torch batteries. Ours had large round double sided almost flat lenses, with a moulded plastic handle on top, mounted to a large plastic rectangular battery box base. As a kid I always assumed they had LDR's inside to turn them on and off at sunset/sun up. However, once I got hold of this one and opened it up, I found there is a small hole through the side of the battery box to poke something through to press a latching push on - push off switch, and no LDR. It blew me away that these things must have meant some poor roadworker had to be going around all the road works every morning and evening manually switching them on and off🤣👍🇦🇺

this circuit reminds me of one they had in the radioshack 75 in one project kit that I had as a young teen back in the 70's. I learned basic electronics with that and the 100 in one kit 😀

OMG I remember waking up in bed with one of those still flashing 😂

I remember these lamps being used to be attached to skip bins back in the 80's here in South Wales

This is so cool bigclive, i used to nick these off road works as a kid and re-wire them onto my mountain bike as indicators, thank you for bringing back the good memories 👍

We used to nick these off skips in the early 1970s when I was a kid, good source of batteries.

@monchavo

2 ай бұрын

Skips generally speaking had these lights attached to them to help warn road users of the presence of something sticking out into the road. I am certain that some by-law changed as, of about twenty years ago, skips no longer are obliged to have this emergency illumination...

@marklatimer7333

2 ай бұрын

@@monchavo Lots of highway laws have changed over the years in the UK, I remember you used to have a parking light illuminated if you parked the car at the side of the road at night.

yeeaaahh big clives got another industrial light. you are a very comforting chap :)

I'm here for all the people in the comments who, like me, would also "borrow" these to experiment on in their childhood :D I remember seeing varieties that had light sensors in, and wondered at the time if they were used to synchronise all the lights up

The memories you invoke are priceless :D We used to pinch them as kids. They were hanging off cones. The ones we took used to flash though with a couple of seconds between flashes like a strobe. I do remember the components were just soldered leg to leg then to the bulb and I'm sure there were only 1 transistor, 1 capacitor and maybe a couple of resistors, if such a strobing circuit is possible from that arrangement. 6 volts was crucial to its operation though, I do remember that, any less (like 3xAA batteries) and it wouldn't work. There were also some with no components, just stayed lit up all the time like a torch. I guess they wouldn't last too long lol

@jussikuusela7345

2 ай бұрын

Maybe a reverse BJT oscillator. It is weird at first thought - no base connection, just a resistor, capacitor, transistor in reverse polarity, and the load to be pulsed. Won't get much simpler.

@JohnnyX50

2 ай бұрын

Thank you, sounds worthy of experimenting :D@@jussikuusela7345

Friday night's + beer = waking up and finding a flashing beacon in my bedroom 😂

I remember you could buy a MES base flashing bulb which had a tiny bimetallic strip inside the bulb, I remember being fascinated how it started to flash (after a short delay) with no other components needed. I guess they were used in bicycle rear lamps and maybe earlier versions of these roadworks beacons. Thank you for the video Clive 👍

@cool386vintagetechnology6

2 ай бұрын

GE bulb type 407. They were used for Everyeady Big Jim torches and similar. A sealed beam bulb at the front and the flasher bulb at the back under a red lense.

@eDoc2020

Ай бұрын

That style of bulb was also used in many pinball backboxes.

I know of a schematic where an LDR ( or phototransistor) was incorporated and that helped to switch the lamp off with a certain delay. Daylight as well as the light of the bulb switched it off so it doubled as a flip flop circuit and a daytime-automatic-switch-off, we thought that was pretty clever at the time.😊

I worked for many years in the NHS (in the UK), those 996 batteries with the springs on top were a standard stock item, every ward would have a basic hand held Ever Ready torch, we used to call them 'nurses torches'. They were used by nurses to do ward rounds at night. 👀

Many moons ago when I was at school in Germany I worked hour-wise on some afternoons at a small factory assembling the German version of this. They were even simpler, using a bulb with a bimetal strip inside to make it flash. After that they also went solid state, and it was my job to populate the circuit boards. there were a few more components on that though. Later on I constructed a LED powered prototype with the first high (ish) intensity clear red LEDs, was sorta OK and the boss was very impressed, but them darn bean-counters killed the project. That was around 1981, LEDs not so super cheap...

A friend of a friend of a friend, definitely not me, "liberated" an early 1970s version of this from some local roadworks and used it to light his bedroom. My friend's, friend's friend was told by his parents to take it back it immediately and was docked a month's pocket money. 1973 had it's ups and downs, ho hum.

Fancy! Last time I pulled one of them apart, was a battery and a bulb with internal bimetal strip in the bulb to do the flashing!

I remember them in the 70s, they used a hex bolt with a ring around it making it impossible to remove without a 'special' tool. A thin walled socket worked! :-D They were attached to barricades (shaped like a saw horse) and the barrel shaped ones used at construction sites. Two modes (continuous ON and flash). When the batteries were new they were nearly as bright as the typical 1157 automotive lamp in turn signals (USA here). They had versions that used a pair of lantern batteries in parallel as well. Sometimes those were attached at the top of temporary road signs in construction zones. Some did have a high intensity flash as others mention dumping a cap into the bulb. Of course with today's tech using LEDs and solar panels one could make them run seemingly perpetually. That is until some prat staring at their cell phone runs it over or a kid swipes it! ;-) Also of interest are carbide lamps! They have a very white light close to that of halogen when run correctly. All you needed was some water and a few chunks of calcium carbide. The reaction produces acetylene which pressurizes the tank and the gas burns brightly when properly mixed with air. Like mantle lanterns they get hot AF and cannot be used in the presence of combustible gases.

There were some which simply had a bulb and a battery. The bulb filament was anchored to a bi metallic strip which bent as it heated, cutting the power then cooled and reconnected. They were a MES base and I definitely used one in a bicycle dynamo. I may still have it. Paraffin road lamps lasted up till something like the 90's. They were made by Chalwyns I think. We used to play with them as kids in the 70's and 80's.

I remember back in the early 80s, there were large pyramid beacons that had a neon tube in them. Somehow, I managed to acquire the top half and was totally facilitated by the neon lamp inside.

I was half expecting a simple bimetallic strip in the bulb. Genuinely surprised to see a PCB in the thing!

As a young teenage dirtbag I used to ride my pushbike around the neighbourhood and knock these things off the roadworks. They were disc shaped with a big box part below that contained the 6v battery. I remember the circuitry was encased in a cylindrical shaped wax with a LDR sticking out. That is what got me into electronics.😅

I obtained one of these flashing things in the early 80s and there was no PCB but instead a bit of tuff cardboard with holes aligned so when the components were poked through they naturally aligned so they could be twisted and soldered. It did have a optical sensor for day / night which might have been a PN photodiode.

back in the mid 90's, around here they started to make LED based road work lamps. my friend and I had to go.. umm, acquire one for research purposes. it took two lantern batteries (this seems to be common in the US vs a singl eone). inside was a small circuit board with a 556 timer and two very high brightness (for the time) LEDs in series. one half of the 556 pulsed the LED at around a 50% duty cycle at 100Hz or so, and it was held off by the second timer through a diode. the second timer made it flash once a second or so with a 40% duty cycle. finally, a photo diode held off the slow half of the timer to stop it flashing during the day. It was very cheaply made too since they are basically disposable, with some brass strips. It'd be interesting to see what's in a "modern" one.

Classic transistor oscillator circuit. Nice!

I remember roadwork lights that burned (probably) kerosene. They looked like bombs right out of Rocky and Bullwinkle. Some kids in the neighborhood stole one and lit it in their basement, and they found out how much smoke one generated, lol. From there it was those horses with disk lamps....

@johnopalko5223

2 ай бұрын

I think they burned coal oil. Really cheap fuel that produced lots of unburned carbon in the flame to incandesce, hence the copious smoke and soot.

"It's very Daleky" ~ Clive 2024

@nholth

2 ай бұрын

I had to re-watch that a few times to make sure I heard it right... AWESOME

Ah, I remember 2 other versions of these. There was the big plastic container for the 2 batteries, a metal bolt for bolting to a skip/stand, then it tapered up into the clear orange disc. Inside was a latching push switch, like the old bedside lights. This was accessed via a small hole in the housing, just large enough for a small terminal driver. The other one was a rectangular all metal affair with the orange lens sunk in the top part and the batteries, flasher and mounting screw in the lower half. Some of these on ebay right now, new old stock. Dorman Smith traffilamp I believe they are called. Also used in some form on UK railways.

I had one of those years ago...it was switched on and off by rotating the amber reflector itself. Had the same 2 BC transistors also. 😊. Thanks for this Clive..brought back some memories

Forgot to say thank you the proper way x Just got back from Prague holiday late last night and first thing I did was watch a Big Clive video 😂😂

@bigclivedotcom

2 ай бұрын

Thanks. Hope you enjoyed your holiday.

I can remember opening one of these and finding the multivibrator cct. We played with it for hours and connected a loud speaker instead of the bulb. Swopped some of the resistors for pots and changed the cap values.. DIY synthesiser on a budget !

You got a posh one there with a PCB! I used to pinch them when I was a kid for the batteries and the transistors. They used the Christmas tree construction for the oscillator in those days!!

I have one of the newer ones that i duacivered, having been yeeted into my garden after some road repairs on my street. It has a big round orange lens and a yellow plastic body, and like this one also uses a 6v lantern battery and a tungsten torch bulb. It's designed to sit on top of a traffic cone and the switch is built into the receptacle for the cone, so it only illuminates / flashes when in position. Very cool decoration for my 'man cave'!

The batteries in these would be the type of thing that in the bad old days of the Troubles would be of interest to certain paramilitary organisations

I remember knicking those as a kid in the early 80's so I could turn my bedroom into a rave listening to Tangerine Dream......

I remember pinching those off skips when I was a kid.

I really like the casing, it's quite neat. This isn't quite the design I remember from my "youth". Those had an oblong bottom and big round spotlight shaped externally mounted lens.

That cylindrical Fresnel lens reminds me of a lamp I had as a child. Thank you.

Fun fact, the voltage on the positive of the capacitor, with respect to 0V, rises to nearly double the supply voltage, minus a diode drop, when the lamp turns on. This is fine at 6V, but if the supply voltage is any higher, it will exceed the reverse base-emitter voltage rating of the PNP transistor, which is typically 6V.

That circuit is very similar to the lamp flash circuit you see in those electronic project lab things for kids. Very simplistic design.

We used to just rip the whole flasher circuit out and have it on in the corner of the room for ages 🤩

You say that circuit was as simple as they get, the ones I nicked as a teenager in the 60s just had a battery and a bulb with a built in bi-metal switch, to turn it on you shoved a pin through a hole to bridge some contacts. I still have a couple hanging in my garage.

@Acamperfull

2 ай бұрын

Yes in the Netherlands we had those to in a rectangular metal box with two parallel 6V batteries inside. This box was closed with a large special anti-theft bolt but one managed with some pliers.

Damn Clive! That was awesome. Also heflp, the cat has taken my arm hostage.

An legendary pair, BC448 and 558. Looks like they are treated quite harshly, I know their max current rating is 100mA but directly driving a light bulb from 548 seems rough... I think they indeed regarded those beacons as half-disposable. I was born and raised in a big city (Cracow), and from university times I remember, that after party nights roadworks beacons had a strange tendence to appear in people's houses. Must be some kind of static electricity phenomenon.

I remember collecting and modifying these beacons in the 80s if I remember right they were a little better built back then withthe the components on the bulb holder with jumpers making up the circuit,,,,the modification was achieved by strapping or inserting fireworks to the lamp 😂,,, Happy 80s FUN

I am reminded of a circuit that I would run into from time to time that was even simpler. It consisted of two complementary transistors, one capacitor, and one resistor. These were sometimes sold as little modules for a code practice oscillator, siren, etc. I'm sure I've seen it elsewhere as well. I cannot remember the exact configuration of the circuit, though. Putting just 3 volts into it, you could directly drive a speaker.

Loved it Clive thanks I did have a few Dorman Smith lights, but I did used to love the paraffin lamps loved the smell

@phils4634

2 ай бұрын

The Dorman Smith "Trafi-Lamp". "Acquired" a number of these as a student, and they were always useful. Used to keep two in the car for when it had problems.

@wisher21uk

2 ай бұрын

@@phils4634 that’s the one, I had a broken one a couple of months ago they use LED’S now

I was expecting a flasher bulb, a 6v battery, and maybe a light sensor.💡 I also wondered how that design required a 10 minute video? 😆 Hate to admit, I’m old enough to remember seeing the type that burned kerosene along highway construction sites when I was very young.

When you said two transistor circuit I was expecting the classic astable multivibrator circuit with the lamp as one of the collector loads.

I had one with the light sensor. It actually affected the oscillator, so that a group of them would synchronise in the dark.

Had about 20 of these I... Ahem.... Found, as a kid. Had them on top of my wardrobe flashing in sequence. My parents were not impressed...

And just to add, my bedroom may or may not have had lots of these!! Nicked on a night time walk home 😂

You've got the posh one! I remember an early version that my brother and I rescued from the roadside after it had been run over by a vehicle, which had one single transistor and a couple of resistors and capacitors. We repaired the circuit, which was literally just the components hanging in mid-air, like a spider's web. The bulb was 6v rated at about 50mA. The flash rate was a bit variable and could be skewed by varying voltage and temperature. In service, I remember these things rarely, if ever, flashed anything like in time with each other! There was another variant that ran at a somewhat higher frequency so that they appeared to be constantly on, but if you shifted you eyes rapidly, you could see a trail of amber flashes in a row along the path of your eye.

I remember the old Dorman Smith Trafi-Lamp versions that took 2 batteries. They had a special low current bulb and would not flash with any other type.

Every student flat had them. Plural. But I also remember going with my dad at dusk to fill the paraffin versions and light them at roadworks pre 1965. Oh, that smell of warm fuel...

Seen many of those through motorway roadworks when I were younger. Those metal hangars were used to hook over the top of the traffic cones.

I always read this far down!

When I was a young lad , I turned many of them into a variable strobe light or parties by replacing that 1.5 m resistor for a 100k and a 2m pot in series. It wasn't that type it was the one that was square and had the large bunny and ear . I made a few bob out of it .