Old Whelen Power Supplies
- Thread starter JohnMarcson
- Start date
Yeah, I have a catalog with a 12vdc M8 that is listed as "the motorcycle strobe". I always thought it looked very aircraft like. What is interesting to me is the industrial version looks just like the 12v version including the heat-sink. I'll have to dig through my catalogs and see the evolution of this style.
Here are he 1976 M80 industrial light page. Also below is the 1981 M90 that replaced it.
Here are some 800/DMS/AE units from 1977 to 1987.
Interestingly, the AE and latest 800 PSs do not have a current-sensing transformer as described in the '507 patent (show by red square).
Neither does the '77 800 but it predates that patent.
It's also dawning on me that the white sticker on the board is a serial number. In every case I've looked at, it matches a number hand-written on the "green tag".
It would neat if we could learn more about this serial number. It might be possible to come up with a "date-your-board" formula or something.
Interestingly, the AE and latest 800 PSs do not have a current-sensing transformer as described in the '507 patent (show by red square).
Neither does the '77 800 but it predates that patent.
It's also dawning on me that the white sticker on the board is a serial number. In every case I've looked at, it matches a number hand-written on the "green tag".
It would neat if we could learn more about this serial number. It might be possible to come up with a "date-your-board" formula or something.
The numbers are an interesting question, I have a few that have a green tag I have not looked at. I have probably about the same number of 800 style lights, the ones with the "squared off" sides are always newest, around the time a similar board was used with stand alone PAR36 strobes in various bars. Oddly enough my oldest one 1976? has a lot less solder on it than the newer ones and looks more sturdy IMHO. I will open some lights up when I get home. Maybe if we compare enough tag numbers we can make some sense of it.
Here are some of my similar sized beacons
1989 Style number 1
1989 Style number 2
1993 Style
Modern (boring) style
I also have this non-whelen beacon that I think was an early version of Lectric Lites maybe. I was hoping to find a tell tale "AE" board inside, but I did not.
Yes! I love these!
The top board is timing and trigger. Yours looks completely built out in that it should do alternating single flash. Others only do simultaneous flash. I'm guessing it was mfg'ed somewhere between '71-'73. For GE, CORNELL DOUBLER and SPRAGUE, they all seem to have some form of a date code on the main caps. If you peak a flashlight indirectly into the PS and use a jeweler's magnifier you might be able to make out the YYWW code on the power transistor so long as its _not_ a Westinghouse...or at least I haven't been able to make sense of them yet.
Yes, this looks alot like an aircraft PS although I don't think I have one that looks quite like it. Single or double flash?
The dome is interesting...the center band in the lens seems very narrow compared to Whelen, as well as FedSig and Tomar beacons I have.
So both Lectic Lites and Rawson Industries were out of Fort Worth TX - (comaring to this) also note the same narrow center band in the lens:
Have you tried Whelen?
Q: If you don't have any tubes plugged in, does it still blow a fuse? It shouldn't. If it does, it might be a hint as to how voltage is leaking to hit the gate of the power MOSFET to get it stuck on as I believe it would in that state, blow the fuse. The MOSFET is supposed to oscillate to drive the inverter.
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I was under the impression that LectricLites was what Rawson Industries started out as, although a "rebrand" is just as likely. I was trying to find a date on something to get an idea as to whether is was a rebrand or early version, but I couldn't find one.
I have not fired up the M80 yet, I need to grab my variable VDC power supply from work.
At the bottom of the blue capacitor, it looks like "820x" - that might be YYWW date code?
Also, I found this thread interesting.
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Looks like it was a separate company, so a rebrand probably. They were only in business from 1978 until 1987. They unfitted earth moving equipment and had a registered trademark "Built Texas Tough"
Registered Trademark
BUILT TEXAS TOUGH
73385247 1274761 Dead/Cancelled
Rawson Industries, Inc.
https://uspto.report/TM/73385247
RAWSON INDUSTRIES, INC. :: Texas (US) :: OpenCorporates
Free and open company data on Texas (US) company RAWSON INDUSTRIES, INC. (company number 0045421400)
So completely OT, as someone who dabbles with Arcade, and Vintage Audio I know the limitations of Capacitors and age quite well. Some of the Caps I see in these pictures are pretty beefy, are you still able to source replacements? I would assume that some of these would be long out of production or obsolete. Just curious if anyone is doing their own repairs.. the older stuff is fairly easy to work on with the right schematics.
I don't repair these much, but when I have the parts have been pretty easy to find.
I've had good luck in that most of the in-op PSs I get, come with working caps. I did get an aircraft PS last week with what outwardly appeared to be nice caps ("GE" 400uf 250VDC, ca 1973) but they won't hold more than ~126 volts. I was wondering if they might need some heavy "reforming" and I found some good YT vids describing the process but I haven't tried it yet (and don't have the eqp either).
I did get a batch of much newer "GE" 300uf 350vdc from 'tedss' on eBay which have worked out well for me in the past.
That said, I can imagine in your application, its really important to have the caps perform close to spec. W/R/T strobe PSs, I don't mind if they're not quite as bright as they should be...it's easier on my aged eyes
EDIT: I had trouble replacing the power transistor on the older PSs (specifically, TI EP447/NES NSE8013/STA7082F and TI EP2189(-B)).
For the EP2189, Whelen replaced it with "TIP35C" which are still around (observed from repaired strobes).
For the EP447(et al), a few later models of UPSs and repaired PSs showed Whelen using a OnSemiconductor "2N3055A". Those that I acquired (from other manufacturers) weren't up to the task and the flash was sub-par. I stumbled on the "Tesla KD503" and so far, its been my preferred replacement (for any old TO-3 package transistor).
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I found patent US3731082 applied for in 1970 really interesting.
I also received a "Lectric Lights" version of this same beacon (same, right down to the board's ID "CHM 02" and "REV F")
The three of four parts with recognizable date codes suggest mine was mfg'd ~1984.
IMHO, this is a very pretty beacon to see flashing (nice well-collected flash in the lense)...but its single-flash. Am I crazy? or by 1984, was dbl-flash kind of assumed/expected?
To keep somewhat on-thread, I got this aircraft PS this weekend and it wouldn't flash. I measured just millivolts in the trigger circuit where it should have read in the hundreds of volts. Turned out this stupid 470K resistor had failed such that the no HV was fed to the trigger circuit. I had to dig away a boat-load of silicone to get at it, remove it, then replace this $0.10 part -- then Viola! she came back to life and flashed exactly as expected, hours on end.
Lectric Lites was single flash for a while in their beacons. They made all the 120v lights that came on at my favorite arcade and those were very slow single flash. I know the Ranger bars never really took hold either, so more of a local niche product?
The aircraft supply I just got does the ramp up but not fire thing my other Whelen beacon is doing, but it's older so there isn't much silicon to dig through.
Are you saying it does the exact same thing? i.e. when you remove power, it flashes? Got any pics?
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I know I responded to this message the day you posted it, but for whatever reason it's not showing up. Maybe I didn't hit post reply or something...
But I did not/have not contacted Whelen as I just assumed they've moved on from strobes and don't service old stuff like that.
As for the fuse blowing without tubes connected, I thought that was for sure a death sentence for a strobe power supply?
I can post a pic tomorrow, and yes it "winds up" but only fires when power is removed. Same issue basically. It's a 4 head older model, I opened it up so I can post pics of inside and outside.
The fuse blowing can be the end of the supply depending on the model. A silicone potted one with all external shorts ruled out, yeah it is bad. An old supply might be fixable based on what component has shorted. RS485 would know better on the specifics.
While a fuse blow is bad, it's not curtains. Is it a single or dual? I have parts for both.
It's a dual. I'm sure it's repairable, but trying to find someone local who actually REPAIRS electronics (not replacing cracked iPhone screens or swapping circuit boards) has been challenging to say the least.
Does your DM2 PS look like this?
Here's what's supposed to happen if you run it without tubes...
It should charge up, try to fire, then either:
1. resume charging but sense CAP voltage is already at/near designed level so it would stop charging.
2. fuse blows.
If the fuse doesn't blow, it hints that when you run with tubes, the discharge of the flashing tube maybe leaking to keep the MOSFET turned on somehow.
MOSFET is this:
If he gets "stuck" on, then current flows directly through the transformer primary coil which would blow the fuse (IRF540 is rated to pass up to 20A -- so it would blow the 5 amp fuse).
The fact that it works to fire one flash indicates that up to the moment of failure, the MOSFET is doing its job (turning on and off rapidly, repeatedly for the 1000 or so charging cycles required to build up sufficient CAP voltage to fire the tube).
While this is a double flash, I believe the basic guts of it are described this patent which contains a sentence, "The gate of Q1 is protected against transients by a Zener diode D3" --
I believe "D3" is this guy:
So at least on paper, this would be what I'd look for first.
John, I have a vague theory about yours where the symptom is that they "wind-up" but only flash when turned off:
If they are PSs according to this patent then something is amiss around "Q1" where the voltage at terminal B2 is staying above where it belongs relative to the emitter (the little arrow, not labeled).
If this is true, and if you have a variable bench power supply and bring it up to the strobe PS's correct input voltage, you might notice that every time you nudge the supply voltage _down_ just a little bit, it will flash...at least that's what I've seen many times with these PSs.
I do _not_ understand this part of the circuit clearly...and I'm still trying to get my head around what the patent says, but I think the effect of B2 seeing any slight voltage higher than intended, has the effect of lengthening the flash time constant.
I wouldn't advise this as an experiment (because of the threat of overcharging the caps) but if the PS were allowed to run, at some point, voltage in C2 will eventually accumulate to be be enough for Q1 to trigger (but it might literally be many seconds/minutes between flashes).
Maybe "D2" is no good and allowing N3 to prematurely "pump back" to raise the voltage at Q1's B2 terminal. Maybe the primary caps themselves aren't up to par but I can't explain exactly why they could cause this problem.
Hopefully, at least an idea or two.
If they are PSs according to this patent then something is amiss around "Q1" where the voltage at terminal B2 is staying above where it belongs relative to the emitter (the little arrow, not labeled).
If this is true, and if you have a variable bench power supply and bring it up to the strobe PS's correct input voltage, you might notice that every time you nudge the supply voltage _down_ just a little bit, it will flash...at least that's what I've seen many times with these PSs.
I do _not_ understand this part of the circuit clearly...and I'm still trying to get my head around what the patent says, but I think the effect of B2 seeing any slight voltage higher than intended, has the effect of lengthening the flash time constant.
I wouldn't advise this as an experiment (because of the threat of overcharging the caps) but if the PS were allowed to run, at some point, voltage in C2 will eventually accumulate to be be enough for Q1 to trigger (but it might literally be many seconds/minutes between flashes).
Maybe "D2" is no good and allowing N3 to prematurely "pump back" to raise the voltage at Q1's B2 terminal. Maybe the primary caps themselves aren't up to par but I can't explain exactly why they could cause this problem.
Hopefully, at least an idea or two.
Actually Whelen no longer repairs those lovely things it's too old we don't have to parts for it anymore it's junk now what would you like us to do with it trash it that was a lovely reply from from Wayland technical support cuz I sent him in a semi-functioning dashmaster 2 or - miser to excuse me and it came back to me broken worse than what it was and I sent it to them since most of their staff that knew what the heck they were doing has gone the way of the dodo bird and been retired there's not much chance of getting anything worked on that was strobe related because they moved on to LED and so should you as per their sayings
You know in fact I have an idea on how to repurpose those dash miser frames into an LED version but I got to get the parts from Whelen see if it fits within its confines could be kind of interesting and I'm surprised that they didn't think about doing it if it fits!
I've never tried them but I've seen them on eBay offering repair of some specific Whelen parts:
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First thing to try is known working caps. These do have screw terminials...some of 'em, you have to desolder which is a slight PITA.