Has anyone made their own electric wire embedder. I know I need a 9-12v transformer, is there a current limit or minimum for this? Can I just connect the DC output to the frame wires directly to heat(short) them? The cost seems high in the beekeepiing supply catalogs. I'm quite electrically adept, seems cheaper/easier to build my own. Ideas? Comments?
Thanks for all info.
Tenderton,
Sounds like an interesting experiment! I use mediums, so I don't wire.
Looking on the current ratings for 26 gauge copper wire, it looks rated for about 2.2 amps, and 0.04 Ohm/foot. Obviously steel is not as good of a conductor as copper, so it will heat up sooner, but my guess would be you'll need around 5amps to get the wire warm.
Technically speaking the heat output from the wire = P = VI = I*I*R. I really have no idea what the resistance of frame wire becomes when it gets hot. That is a big unknown that radically changes the calculations that follow. Let me just guess 1 ohm and see what the numbers say.
To melt wax, you probably need the wire to generate about 20 watts of heat. We now have enough data to run the calculations
P = IV = R*I*I
20watts = 1 Ohm* I*I. Solving for I we get 4.4 amps.
Getting 4+ amps out of a transformer will not usually be your most cost effective approach. When you need more that a couple of amps, the most cost effective power source is an old (or new) computer power supply. They can output a good 30amps at 12VDC is you need it.
If you use a 12volt output from the supply, at 4.4amps, you'll drop 4.4volts over the 1.0 Ohm (?) frame wire which means you would need to drop the remaining 7.6 volts over a current limiting resistor. However 7.6V x 4.4amps = 33watts. You would need a current limiting resistor rated for 33 watts. That is completely impractical.
Computer power supplies also have 5volt and 3.3volt outputs you could try. These are typically good to 20amps. IF the resistance of the wire does go all the way up to 1 Ohm when hot, then a direct short to the 3.3v supply would flow 3.3amps and deliver 10 watts of heat to the wire. That MIGHT work IF the resistance of the embedding wire goes up to 1 Ohm. If the resistance is less than 1 Ohm, this sucker is going to get RED hot without a current limiting solution.
IF a direct short to the 3.3volt supply half works, but doesn't give you enough heat, you might a direct short to 5volts.
Really the BEST solution and the most controlled solution is to PWM your power going into the wire. This allows you to deliver the exact current into the wire you want. You don't have to worry about dropping voltage over a current limiting resistor in this case. I would get a nFET rated at 10 to 20amps and PWM your 5volts thru the FET and into the wire for a nice controlled heating solution.
ALWAYS remember fooling with electricity is DEADLY dangerous. It only requires 50mA to stop your heart. Always follow good electrical safety habits.
I fully Agree :shock:
:-D
http://forum.beemaster.com/index.php/topic,7534.0.html (http://forum.beemaster.com/index.php/topic,7534.0.html)
Do it the old fashion way;
Use a door bell transformer !
Bee-Bop
QuoteHas anyone made their own electric wire embedder.
Is this a back yard operation? Just use a car battery 12V and knock it down with a home made resister. Resistance is dependant on the wire and its length. You can take bailing wire and carefully wind it around a stick to make the resistor (coils can't touch). Use heavy clip leads to connect one end to the battery post and one to the wire you want to embed.
Nothing below 24 volts can affect your heart.
My calculations were all theoretical since I have never embedded wire into foundation. Since Bee Bop has done it with a door transformer; that would definitely be a lower cost solution. Home Depot sells door transformers. It's been a while, but I seem to recall them running about $5.
If you want to play with more current, you can usually find a computer power supply on sale at NewEgg or TigerDirect for about $20.
i just use a car battery charger.
I have use the same door bell transformer (12v) for the last 35 years and I made my own electric wire embedder.
(http://kelleybees.com/Files/Organization3/Images/Products/Thumbs/22047.jpg)
BEE HAPPY Jim 134 :)
an older car battery charger should work fine...a new fangled electronic one probably won't.
also, an older doorbell transformer will probably work (they were built better)...i've blown out a couple of newer ones, they are not as rugged.
i've see some scary setups (wall current and an old electric iron), which i would not recommend.
best bet is the embedding transformer sold by kelley:
http://www.kelleybees.com/CMS/CMSPage.aspx?redirect=n-3-47956a28-1ea0-4680-a3dd-543ed5c765f7 (http://www.kelleybees.com/CMS/CMSPage.aspx?redirect=n-3-47956a28-1ea0-4680-a3dd-543ed5c765f7)
...you can get the transformer only for $20, or $35 mounted in a box with a cord.
deknow
Quotebest bet is the embedding transformer sold by kelley:
I designed an automatic pantograph for cutting wing ribs out of Styrofoam using a car battery charger. The safest way for someone not knowledgeable about electricity is battery power. I don't care what charger you have if it is connected to the battery while you are using the current from the battery it will work fine. The only thing you have to do is limit the current in some way so the wire doesn't get too hot. You can use light bulbs in series, wire, commercial resisters or rheostats. The current required will depend on the size of the wire, length of the wire, and material that the wire is made of that you are embedding.
i don't agree. a battery can explode from being shorted out (which is essentially what you are doing when you embed wires).
a battery as part of your embedding setup can leak even if it doesn't explode. i'm not sure what a newer electronic charger will do if attached to a battery and used for embedding at the same time, but i'd be surprised if the charger didn't at least report an error, if not shut down. if you "have to limit the current in some way", all of a sudden things are much more complicated, and no guidelines are offered by you (the person recommending this approach) as to how much to regulate the current, how to know if you have not regulated it enough, or too much. i don't disagree with you in theory, but for someone that isn't used to dealing with electricity this gets overly complicated for no good reason.
$35 gets you a proper transformer mounted in a box with a power cord and 2 leads designed to safely and effectively embed foundation.
a new battery is probably going to set you back at least as much as the kelley transformer mounted i a box...a used battery is likely to leak eventually.
batteries are large, heavy, can damage the area where they are used or stored, and require proper disposal at some point.
deknow
Quote$35 gets you a proper transformer mounted in a box with a power cord and 2 leads designed to safely and effectively embed foundation.
I yi, yi come on. the current is dependant on:
QuoteThe current required will depend on the size of the wire, length of the wire, and material that the wire is made of that you are embedding.
It is not dependant on the transformer, battery or what every assuming the voltage is constant. I said a 12 volt car battery. The wire will fry long before the battery will explode. If you don't get a big enough transformer it will fry plus you are usually dealing with house current 110-120 volts which is deadly!
Now people can do as they wish but the safest method is a car battery not a cell phone or computer or any other battery you might find in your house. You can charge the battery afterwords. The only reason for charging while you are working is so the volts don't drop. If you are working on just a few frames it isn't going to drop that fast.
Hey AceBird,
Can you tell us about your Styrofoam cutter? I have made one too, but mine still doesn't work that great. I of coarse cut Styrofoam for my foam hives.
I've got a reel of old heater wire (Nickel Chrome, 22Ohm/foot, 35 gauge) from the 1980s that I used. I use a piece about 3" long and short it directly across the 12volts from a computer power supply. The 22 Ohm/foot limits the current automatically in this case (probably to about 2 amps). P = VI so 12volts at 2amps = 24 watts of heat from the wire.
My wire glows red and it does cut 2" foam, but it's still slower at cutting than I would like. I would like a setup that can cut 2" foam as fast as a table saw. So how does yours work? What kind of wire are you using?
As for shorting a LEAD ACID battery it might be worth pointing out that you do that every day when you start your car, especially in the winter. Until the motor starts turning, there is no back EMF in the starter motor to limit the flow of current form the battery and you have a direct short through some very thick wires. Even after the motor starts cranking, the starter motor pulls enormous currents from the battery on a cold day when your engine oil has the consistency of molasses.
The real danger comes when it's time to recharge your dying or dead lead acid battery. That's when water in the electrolyte can be split into H2 and O2. That can explode. Of course there is also the danger of acid getting out of the battery or dropping the sucker on your foot.
I agree with deknow that for the cost of a battery + charger + disposal, it would be much wiser to simply buy the thing from Kelley's!! (ACE, I also agree with you that 120VAC is Deadly dangerous)
I was told DC is deadlier to the Human than AC
If that is so ?
Would in not be safer to make a Low amp AC
Tommyt
Tommy T are you trying to restart the "war of the currents"? Edison vs Tesla?
AceBird, I'm not touching this one :)
Isn't it the reason the arc from the solenoid can kill :?
Tommyt
QuoteI was told DC is deadlier to the Human than AC
Dead is dead. It doesn't matter which one stops your heart or actually puts it into fibrillation.
Bluebee, just about everyone has a battery in your car. Make up a long extention cord with clip leads and it will help add some of the resistance you need to drop the current.
QuoteIsn't it the reason the arc from the solenoid can kill
If you are talking about the ignition wires the voltage level is up around 30000 V not 12.
AceBird, you win the quote of the day contest: "Dead is Dead"!
Well said AceBird.
I know this is a little off topic, but since we're talking about AC/DC here (as in current, not group), you might want to check out Green Field Village the next time you're in Metro Detroit. It's a pretty cool place with lots of displays from Edison and Ford. They were buddies. In fact Green Field Village has some of Edison's original building from Menlo Park, NJ. The building is restored to how it was when Edison invented the light bulb. Lots of cool techno gadgets to see in Edison's old shop.