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With the way a dimmer works (switching off the power at the beginning of the cycle) does that signifigantly reducethe life of heating elements? Namely UTH and CHE?

Thanks,

Joe Conklin

>>With the way a dimmer works (switching off the power at the beginning of the cycle) does that signifigantly reducethe life of heating elements? Namely UTH and CHE?

Yes that is how a "modern" dimmer switch works and this question would be easy if the dimmers from yester-years were still being used.

I have no define answer for you only the manufacture can give you that.

The modern dimmer works exactly like a rheostat or amazingly enough an On/Off thermostat. But suprsingly less complicated. So if you would use on of those items on a UTH or CHE then yes I suppose it wouldn't be a question.

What product does the manufacture recommend if its their own rheostat or on/off thermostat like a Ranco. You would be safe and the manufacture doesn't see a problem with it. But if they recommend a proportional than I suppose a dimmer is out of the question.

You have to remember that the products you mentioned don't have elements like a light bulb that wear out when turned on and off repeatedly. So are more resilient to change. I probally didn't answer any questions. But if you can use a light bulb with a dimmer and not significantly shorten the bulbs life then I doubt it will hurt a UTH or CHE.

I could be totally wrong on the other hand.
Jeremy
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True. But what hurts a lightbulb is complete on/off cycles (cooling completey and then reheating completely). That creates a lot of thermal stress. I guess if UTH and CHE are less prone to on/off wear they should be ok. That was my real question if it effects these items more of less than a normal light.

Joe Conklin

The on off cycle of a bulb causes it to burn out due to the amps it draws while the element is cool. If you measure a 100 watt bulb, apply ohms laws it comes close to 10 amps!. But as the bulb heats (quickly) the filaments ohm value changes to about 1/10th the value. Well actually 10 times the value as higher resistance equals less wattage in this application. A light bulb on a dimmer ran at 90% power would probably last 3-4 times it's normal length. And bulbs have a estimated on off life cycle as well as hours life span. This only applies if a dimmer is shutting off at the dim end of it's dimming ability. Some dimmers do have an added push button to turn on the light and off, instead of dimming to the off position. Obviously not as good.

As far as UTH's I've never ripped apart the stick on type, I just have old metal pads, that use to be rabbit heaters. Like human heating pads, they just use resistor wire. NOT near as delicate as a light filament in a light.

I use lamp dimmers from lowes or home depot, they work up to 300 watts. at $15 the can quickly pay for themselves.

If resistor wire was to burn out then incubators would burn out, as that's all they basically are. An above the egg heater. And it goes on and off all day to keep the temperature steady. Well, that's the way I see it. Dimmers add to life span, especially in bulbs, IF, you have to go to the off position by dimming, and more importantly turning it on through the dim process. This stops that big shock to the filament.
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1.3 Bearded Dragons
2.4 Ball Pythons,
6 baby female Western hognose, 3.5 adults some friend some mine,,,building breeding stock)
1 Corn snake (bloodred) MIA
Rats, Degus,
2.0 Dogs,
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tom

www.herpzilla.com

Thanks for the answer, exactly what i was looking for. I knew about the resistance of lights and i knew why they burned out due to on/off cycles not sure what i was talkin about last time Oh well atleat the correct info is out there now.

Thank again,

Joe Conklin

Years ago, when I had big snakes and made big cages out of plywood, I use to use regular lights to heat them. Through my train hobby and a nieghbor that was an electrician that loved to tinker, I learned to place 2 regular sockets in series, hence each running at 60 volts. So we bought 150w-200watts to compensate for that. Bulbs lasted many many years. Glad I could help. Some day I hope to be able to get my work shop up and tinker again myself.

Take care
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1.3 Bearded Dragons
2.4 Ball Pythons,
6 baby female Western hognose, 3.5 adults some friend some mine,,,building breeding stock)
1 Corn snake (bloodred) MIA
Rats, Degus,
2.0 Dogs,
0.2 Cats,,
0.1 Wives,
1.1 Kids (Paininthearsius takamemonii) J/K great kids
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tom

www.herpzilla.com

I madea reostat and figured that the dimmer wouldn't hurt it, but i wasn't exactly sure what was inside an UTH. I figured it was just a resistor of sorts that heats up (like a human heat pad) but wasn't sure as i've never disassembled one.

Oh ifi can find some good free webspace i might post links on how to makea reostat box (dimmer/outlet in one plasticelectrical enclosure,total cost was about15 dollars) if any one is interested (real real easy).

Joe Conklin

OK, stores sell a "lamp dimmer" UL approved. Rated at 300 watts.
cost was $15.

I do know how to make my own as some do. I personally have an issue with posting "how to's" on such an item. I know my skill levels, and if I make something from my own abilities it's my fault if something goes wrong. But posting a plan for an electrical setup scares me. Beyond the idea of being sued, I would feel horrible if someone made an error, or worse I had errored. There is more to electricity than most realize. 120 volt AC use in just a resistance setup has basically SOME of the same properties as DC. 120 volt AC is the heat equivalent of 120 volt DC, as 120volt AC is the MRS value. Things change in a big way when a coil of capacitor is involved creating inductance and capacitance, making up impedance through total reactance. Something along those lines.

OK, it's an odd post, the reason is electricity is something not to play with, unless you "really" understanding the dynamics of the setup.

I just do not want some one to hurt themselves or others, especially when there are store bought options available.

be safe
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1.3 Bearded Dragons
6 baby female Western hognose, 3.5 adults some friend some mine,,,building breeding stock)
1 Corn snake (bloodred) 0.1 MIA
1 baby creamcycle 0.1
Degus
2.0 Dogs,
0.2 Cats,,
0.1 Wives,
1.1 Kids (Paininthearsius takamemonii) J/K great kids
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tom

www.herpzilla.com

At 120v a 100 watt bulb will only pull 1.2 amps using OHM's law.
Wil

>>At 120v a 100 watt bulb will only pull 1.2 amps using OHM's law.
>>Wil

P = I x V
100w = I x 120v
I = .833... you forgot a step.

BUT

V = I x R
120w = 833... x R
R = 144ohms RIGHT?

now measure a bulbs ohm value OFF. It's the only way to really measure resistance, if it is "on" you calculate it. I have not measured ohm values on bulbs for 25 years, but as my old mind recalls it's about 1/10th the value, lower ohms cause higher current draw. The bulbs filament heats up and the ohm value drops, very FAST. To that oprating value above. This is why bulbs rarely burn out just running, but usually as you turn them on.

Heck maybe I'm completely wrong. But thats thats the way I recall the numbers.

I use to tinker A LOT. And not with light bulbs, crazy stuff like using a 1964 t-bird starter motor for a mini bike. That stater has a long shaft like a reg motor. But I had to make huge wire resistors to carry the loads, yet drop the voltages for verious speeds. As those wires got hot, my motor slowed, this lead me to my nieghbor who again was way beyond my young mind and taught me some basic DC.

If I'm wrong I really want to know, ld people have limited brain space,, if this inf is wrong I can do a memry dump of that portion and you it for something else.

Old brain cells never die! They just,, er ,,, ah,, I forget?
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1.3 Bearded Dragons
6 baby female Western hognose, 3.5 adults some friend some mine,,,building breeding stock)
1 Corn snake (bloodred) 0.1 MIA
1 baby creamcycle 0.1
Degus
2.0 Dogs,
0.2 Cats,,
0.1 Wives,
1.1 Kids (Paininthearsius takamemonii) J/K great kids
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tom

www.herpzilla.com

Sorry, I put the numbers backwards on the calculator last night.
My point is that a 100w light bulb will only pull .833 amps and not 10 amps. I see nothing wrong with any of your other statements. You have a really good grasp on electricity. Especially that it hurts when it bites.

Thanks, I read your posts a lot. You offer many people a lot of more specific knowledge. I'm glad you did not take that post the wrong way, after I posted it, I read it and it could have been taken a bit rough. I was just trying to be a bit facetious.

I got back into herps about 2 years ago. I'm unlearning a lot of bad stuff. And learning a lot more. I just wanted to be sure you did not take that post as I was ripping on you. Backwards placing numbers I was expert at, especially in Calc!. lol..

I lurk a lot here. Post once in a while if something really catches my eye. The herp market seems to prey on newbies. Not you people the big companies. I have done a lot of research on lighting. I just had a customer ask me about a UVB bulb. "5% of what?" I (and if you really knew me, this is rare), did not have an answer. I can spout ranges of UVB UBA and UVC, and lots of other info. Like many people in here we love to gather info. All I could do is say; I'll have to get back to you, as I do not BS our customers.

OK, I'm rambling,, back to lights. RIP OFF, Thomas Edison’s lights are still working!! And we cannot get bulbs to last a few years? That's BS. I'm probably older than most here, bulbs lasted years when I was a kid. Again my friend and I debated this topic for many nights,(lots of spare time). One, is a planned obsolescence? Or older houses had 14 gauges wiring, and with newer higher load devices, it could lower home voltages a bit, causing longer life. I say planned obsolescence. Companies get us use to inferior or smaller products, just to offer the older now bigger or better products. Toilet paper is a well-documented item. They make it more fluffy (air) to make rolls the same size with less paper, and then offer new bigger rolls.

OK, I'll cut this post short. lol

Take care
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1.3 Bearded Dragons
6 baby female Western hognose, 3.5 adults some friend some mine,,,building breeding stock)
1 Corn snake (bloodred) 0.1 MIA
1 baby creamcycle 0.1
Degus
2.0 Dogs,
0.2 Cats,,
0.1 Wives,
1.1 Kids (Paininthearsius takamemonii) J/K great kids
-----
tom

www.herpzilla.com

Tom,
No, I didn't take your post the wrong way. I know it is hard to convey any tone in posting. That is why I would prefer to talk to someone directly, either in person or on the phone. I also agree with you 100% that new persons coming into this hobby are targeted by many people. There is a lot of information out there that is either completely wrong or only given in bits and pieces and the people giving it don't excactly know how to apply it themselves. Now I will be the first to admitt that I don't know everything, but I am happy to share some of the things I do know. I work on units that are big enough to walk into all the way to window units on occasion. There is a couple of things that will never ever change. The laws of electricity i.e. OHM's law and the dynamics of heat and heat transfer i.e. refrigeration theory. I have been keeping herps longer than I have been working in HVAC, but I am fortunate that the two can complement one another. Hopefully this didn't bore you too bad,lol. And if you ever need anything don't hesitate to email me or give me a call.
Thanks,
Wil Combs
Captive Bred Creations

Thank you
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Computers don't make errors. What they do, they do on purpose. (Dale Gribble)

AOL IM Mettzilla
I forgot my password for herpzilla, and gave a bad email,, major OOPS

1.3 Bearded Dragons
6 baby female Western hognose, 3.5 adults some friend some mine,,,building breeding stock)
1 Corn snake (bloodred) 0.1 MIA
1 baby creamcycle 0.1
Degus
2.0 Dogs,
0.2 Cats,,
0.1 Wives,
1.1 Kids (Paininthearsius takamemonii) J/K great kids
-----
tom

www.herpzilla.com

You applied Ohm's law to a fixed resistance value. Thing is, like HerpZilla said, the resistance of a light-bulb filament changes and is much lower when cool compared to when heated up and giving off light. So, the initial current draw is large, like 5-10 times the steady-state current draw. Fortunately, it only lasts a fraction of a second typically.

A 5-10 time amp increase lasting only seconds is called locked rotor amps. That is found in motors, but I can't see that happening to a light bulb. So I tested it myself. First I used my digital amp meter, plugged in the light and it went to .5 amps. Then just to be sure, I used my analog amp meter which can read a potential relay that closes and opens in a blink of an eye. I plugged in the light and no spike, it went to about .5 amps and stayed. Now using OHM's law:
The bulb was 75 watts, voltage 120v, amps when done with ohm's law is about .62amps. Close enough for government work. The point is I tested it and there was no amperage jump.
Wil Combs

Your instruments are way too slow in response time to catch it. Using a digital meter to record current surges that are that fast is like trying to record an instantaneous temperature change with a mercury thermometer. Your analog meter is too slow as well for this application.

Locked rotor in motors is entirely different. That has to do with electro-mechanical stuff, magnetic fields and such.

There is a surge in light bulbs (filament type.) It really doesn't matter for our herp applications in that it doesn't cause any problems, but it does happen.

Stator lock is in a way similar, but not that close.

Just measure the ohm value of a bulb, NOT on. Apply laws school. That HAS to be the initial amp draw, even if for a millisecond.

I'm not up on the hardware to measure such a spike at the beginning of a closed circuit.

Ohms of a cold bulb and running amp draw on a bulb in load
compared do not match up mathematically
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Computers don't make errors. What they do, they do on purpose. (Dale Gribble)

AOL IM Mettzilla
I forgot my password for herpzilla, and gave a bad email,, major OOPS

1.3 Bearded Dragons
6 baby female Western hognose, 3.5 adults some friend some mine,,,building breeding stock)
1 Corn snake (bloodred) 0.1 MIA
1 baby creamcycle 0.1
Degus
2.0 Dogs,
0.2 Cats,,
0.1 Wives, (Long term captive!,, I mean ME!)
1.1 Kids (Paininthearsius takamemonii) J/K great kids
-----
tom

www.herpzilla.com

A dimmer does not reduce heater life. It still switches ON/OFF at 60Hz, no different from regular AC voltage, except that where regular AC is a sine wave, the output of a dimmer is a sine wave interrupted by OFF times to reduce power to the heater.

Heat pads (other than the mylar-coated Flexwatt-type heat pads,) heat rocks and maybe even ceramic bulbs (don't quote me on the ceramic bulb statement) use nichrome resistance wire. There is some degradation of the filament over time if maintained at high temps, but for normal herp-related temps, no worries. Dimmers do not speed up the degradation, and they likely slow it down. Certainly true for ceramics. Dim them all you want.

Hi, you seem to have cracked open a few things to play. COOL. Old hot rocks circa 1974 used a 2200 ohm resistor 10 watts, uses 7.2 watts. Rocks stink thou

My real question, I need HELP finding the wire in the hobubators. SP?

I alwasy find double constant current wires so popular now.

Looking for single wire, insulated. They also use it in rabbit hutch heater. I do have a few pieces but sadly have never done an ohm check. Seems like it would be a realatively cheap item. I have many uses for it, but I can not find it.
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Computers don't make errors. What they do, they do on purpose. (Dale Gribble)

AOL IM Mettzilla
I forgot my password for herpzilla, and gave a bad email,, major OOPS

1.3 Bearded Dragons
6 baby female Western hognose, 3.5 adults some friend some mine,,,building breeding stock)
1 Corn snake (bloodred) 0.1 MIA
1 baby creamcycle 0.1
Degus
2.0 Dogs,
0.2 Cats,,
0.1 Wives, (Long term captive!,, I mean ME!)
1.1 Kids (Paininthearsius takamemonii) J/K great kids
-----
tom

www.herpzilla.com

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