I just got one of those neat Miller Engineering animated billboards.
I didn't opt for the track power unit or adapter to replace the 3AAA battery pack, because I have a drawer full of similar adapters.....I think.
However, it pays to ask.....Miller Engineering's replacement adapter is 4.5. VAC
My adapter is 4.5 VAC 600mA. It is just a simple unregulated Class II so it tests out as having 7.4 VAC available....just like Miller's I'm sure.
So,..... good to go?
(I have emailed them, but thought I'd ask the clever fellows in this forum for an early word).
Thanks
Not even close. Your power supply is AC, and Miller's power supplies are all regulated DC output. Miller Engineering electro-luminescent signs all require 4.5 Volts DC, not AC.
If you go to the Miller Engineering web site they say very specifically that their power supplies are AC/DC adapters, meaning that the input is AC but the output is DC @ 4.5 Volts, and they are all regulated outputs..
If you were to connect your AC power supply to the Miller sign, it may glow very brightly for a short period of time, but will undoubtedly begin to smoke and maybe even burst into flame and emit lots of toxic, burning plastic smoke.
Thanks Mr. Cacole.
I was typing too fast. I know what you mean.
My adapter is DC 4.5 V..or I would not have even written the post.
However, I am almost certain that the Miller Engineering adapter is not regulated and puts out the exact 4.5 Volts.....not for the price of $7.95. (and I see these listed elsewhere for only $3.95 and others at 1000mA for the same application. ) Most regulated adapters I have seen are a few dollars more. But I don't think the unregulated adapter with some dirty DC and a little ripple AC voltage is going to be an issue.
I've got nine of the Miller Engineering signs running off a Radio Shack 4.5v dc 700ma wall wart and they all work just fine. I did just check the specs on the unit itself, and it does say that it's regulated.
Regulated means that it will supply the proper 4.5 volts regardless of the load up to the rated 700ma. An unregulated wall wart will only supply the rated voltage when the rated load is applied. If a lower rated load is applied, the voltage will be higher exponentially to the lesser required load on it. That's why when you buy a cordless phone, drill, etc. - you must use only the wall wart that comes with it.
Either make sure your wall wart is regulated or run down to Radio Shack and get one that is, otherwise you run the chance of overdriving your circuit and burning it out or severely shortening its life.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Thanks all for taking time to respond.
I just got a return email from Miller Engineering....even at 8:30 pm Pacific Time. Nice that they are on the job and answering emails at all hours.
For anyone interested here is the email text from the manufacturer re: adapters...
So I am ok as I thought.
Regulated adapters are rarely necessary and I haven't seen many sold in consumer electronics at all.
Something Chris didn't elaborate on with you is the fact that while these signs WILL operate at a higher than rated voltage - it will cause them to deteriorate at a faster rate.
These sign don't have a near infinite life span like an LED. When I spoke with Chris about this some time ago, I was actually surprised that their life span was so limited .... something like 1000 hours at the rated 4.5 volts. Running at peak voltage of around 6 volts, their life expectancy diminished to around 700 hours if I recall correctly - you might want to verify this with Chris as it's been a while since we went over this.
Simply put, a very high voltage / low current is applied to the laminate which causes the phosphores between to glow and these phosphores lose that ability to react over time .... the higher the voltage, the quicker they break down.
My local hobby shop had one on their display layout which was on whenever the store was open .... it lasted about a year and a half, then just kept getting dimmer and dimmer until it finally quit working. If you plan of running your sign a lot, I'd really recommend getting the properly rated power supply to get the most life out of it you can.
Mine run on the Radio Shack wall wart with no problem. I also only use them when company is over to extend the life of the unit. We do the same at the Club.
Springfield PA
Mark R. Something Chris didn't elaborate on with you is the fact that while these signs WILL operate at a higher than rated voltage - it will cause them to deteriorate at a faster rate. These sign don't have a near infinite life span like an LED. When I spoke with Chris about this some time ago, I was actually surprised that their life span was so limited .... something like 1000 hours at the rated 4.5 volts. Running at peak voltage of around 6 volts, their life expectancy diminished to around 700 hours Mark.
These sign don't have a near infinite life span like an LED. When I spoke with Chris about this some time ago, I was actually surprised that their life span was so limited .... something like 1000 hours at the rated 4.5 volts. Running at peak voltage of around 6 volts, their life expectancy diminished to around 700 hours
Thanks, Mark
As often, what seem like simple little topics end up teaching me more and more about the weird and wonderful world of electronics.
I understand what you say. In my limited knowledge, isn't it the case that although there is excess voltage available from the unregulated adapter, the sign will only draw what it requires. So maybe no difference in hours because of that? But I did read in an article about regulated vs unregulated adapters that "unregulated DC power adapters have a fairly significant AC "ripple voltage" component (known as noise)" that can cause various erratic problems of some components. Maybe this shortens the life.
In any case it seems prudent to use a regulated adapter, so I will. Thanks.
There is no "excess" voltage - whatever voltage a supply provides is what the circuit gets (try running a 4.5 volt bulb on 7 volts - the bulb gets the full 7 volts, not just the 4.5 it requires). Current works as you describe - if a circuit requires 100ma and you're using a 700ma supply, the circuit will only draw the 100ma it requires.
As for the AC ripple in unregulated / unfiltered supplies, electronic circuitry can be very fussy about this - especially integrated circuits (IC's). It can cause a number of problems anywhere from something as simple as a flasher IC either flashing eratically to the entire circuit just plain not working.
Regarding the functionality of these electro-illuminescence signs, the AC ripple in an unregulated supply is not a concern as the board circuitry and step-up transformer will quelch it. The problem in this case scenario is the supplied voltage being on the high side. Your unregulated wall wart would be fine if it had a lower base voltage rating.
Ultimately, I'm not so much cautioning you about the supply you have just plain not working (it will), but rather a concern regarding the higher voltage shortening the life of your sign.
Thanks, Mark.
I understand your comments and I appreciate responses just so I can learn a little more each time.
And the final word from Miller Engineering. When asked about the hours a sign would last Chris from Miller Engineering responded that they will replace any sign for free that stops working.
Can't ask for more, eh?
Cisco Kid And the final word from Miller Engineering. When asked about the hours a sign would last Chris from Miller Engineering responded that they will replace any sign for free that stops working.
That sounds like a truly outstanding warranty -- just about the best anywhere.
Catch 22: What if the one you have has been discontinued ?
Really ? - That's like Sylvania or GE saying they'll replace for free any light bulb that burns out ! .... they'd be giving away a LOT of free light bulbs.
There has to be a time limit as EVERY sign will wear down and quit working eventually.
........ I mentioned this to someone and they wrote of contacting you in the past to learn about the life span of the little signs. What he wrote leaves me satisfied that the sign, even on a shortened life, will be very useful to me...... ..is the following comment from a fellow on a forum accurate?
I find MIller Engineering's statement that their power adapter is unregulated rather strange, since I have one of their type 4804 Converter Modules and it has an LM 2940 Voltage Regulator on the board.
Are they saying that the regulator is there but isn't doing anything ?
Their wall-wart power supply may be unregulated, but the 4804 definitely is. If you look at their picture of the 4804 on their web site, you can even see the regulator (if you know what to look for).
Yes, the 4804 unit that is intended to power the signs from your track or power/throttle pack may well be regulated, but I had asked about the simple wall adapters.....my litlle signs are over top a wall outlet and easiest to use one adapter for several signs from there. I also have my wall outlets switched so I can have one kill switch to turn off all elements in the layout room.
I have over 18 of the Miller Engineering signs and use a 5 Volt regulator with a 330 Mf capacitor in each of my buildings which allows me to run a 12 Volt AC or DC bus line around the layout. I use only 12 Volt DC but figured when the itme comes to sell the building(s) on EBAY a buyer could use the building on AC or DC power up t0 18 Volts from a supply.
The problem with the wall warts is they wiill only supply a limited amout of power (milli amps) so if you intend to add more signs you will need more and more wall warts. I even upgraded to laptop power supplies at 5 amps each but finally purchased 2 12A regulated computer supplies from Al lElectronics for about $12 each.
So, 5 VDC works great with Miller Engineering signs.
Thom
Cisco,
I forgot to mention there is also a bridge rectifier in the circuilt beofre the regulator and the entire circuit fits easily on a 1.5" x 1.5" board. If you need a wiring diagram please email me cadman1@dslextreme.com
Hamltnblue Mine run on the Radio Shack wall wart with no problem. I also only use them when company is over to extend the life of the unit. We do the same at the Club.
I am with you on that. I only turn it on to show it off when people are over. As long as Murphy doesn't show up like he always does when you show your guests the layout.
Truck.
We have several signs on our club modular layout, not sure what they are powering them with, but I'm pretty sure it's the same 12V accessory bus that powers everythign else, since there aren't extra wall-warts to plug in when we set up. Like everythign else, they are powered on just prior to the time a particular venue opens to the public and stay on until close. That should be accumulating run hours very quickly. Since I can;t get to every show, a dimming of the animated signs should be more apparent to me - I'm going to keep an eye on these.
I did have some night lights that used the same sort of EL technology that after 3 years of 24/7 operation were getting dim - however they are set up as cheap as possible and probably didn;t even full wave rectify the 120VAC - I never took one apart to see though. I did take apart a newer LED one that failed - and it's little wonder it failed - the LEDs are actually still good, but the only rectification is a single diode inserted between the two LEDs to block excessive reverse voltage. Voltage is reduced by feeding one side of the AC line through a resistor before the rest of the circuit, which is a simple 1 transistor switch with a CdS cell.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.