| Author | Message | |||
     Anonymous |
How do you make a battery | |||
| Simon Quellen Field (Sfield) |
Batteries are actually quite simple to build. What you need are two metals of different types, such as steel and aluminum, copper and zinc, and a liquid that conducts electricity well, such as vinegar, lemon juice, or salt water. Towards the bottom of my "Three Penny Radio" project at "http://scitoys.com/scitoys/scitoys/radio/three_penny/three_penny.html", I show how to make a battery out of stainless steel bowls and aliminum foil, using vinegar and salt as the liquid. Some web sites to visit: "http://members.aol.com/dswart/index.html" "http://tastesalike.com/ksf/projects/project1001.html" "http://www.hunkinsexperiments.com/pages/batteries.htm" (note that the battery made there out of coins uses two types of coin, each made from a different metal). "http://www.energyquest.ca.gov/projects/lemon.html" "http://www2s.biglobe.ne.jp/~syuLove/potato.htm" "http://tastesalike.com/ksf/projects/project1001.html" | |||
| Joshan |
hi.i have been trying to build up an fm radio, but i have not found any circuit diagram including list of components and i wanted to build one with an extended frequency response, that is, it can pick up signals more than 108MHz.i would very much appreciate if you could,provide me with a circuit diagram and list of components. what would happen if you connect 1 more variable capacitor to the a.m radio circiut(increase the capacitance)?? you ought to know that i am in my GCSE year and that i have limited knowledge of electronics. thank you very much for your help+the website is great!!! | |||
| Simon Quellen Field (Sfield) |
You need this book. On the web try here, or here. There are dozens of web sites with this information. Do a Google search on "fm radio circuits". | |||
| Simon Quellen Field (Sfield) |
As for your second question, adding another capacitor will lower the frequencies the radio is able to tune into. | |||
| Anonymous |
I am building a treehouse and I want to have electricity in it. I want to have electricity generated by a solar cell, wind turbine, hand crank etc. I know I will not have steady voltage coming in and I want to store energy in a battery. how can I set this up so I will have a little electric power to my tree house. | |||
| Simon Quellen Field (Sfield) |
You might like my treehouse. There are many 12 volt solar battery chargers on the market, such as this one. There are also many solar battery charger circuits available on the Web. Deep-discharge marine batteries are ideal, but a used car battery should do fine, even if it won't hold enough charge to start a car anymore. There are lots of neat gadgets that run on 12 volts, made for cars and recreational vehicles. My treehouse has lights that plug into cigarette lighter sockets, which you can get at auto parts stores, or at Radio Shack. | |||
| Anonymous |
I have two questions, well I have more but I'll stick with just 2. I got SIKED by the AM radio transmiter and I was wondering... 1 How could I increase the range of the transmitter. Should I use a bigger battery or bigger antenna. 2 How can I turn the AM transmitter into an FM transmitter. Thank You and this is an AWESOME site. (I checked if Radio Shack had overnight shipping) | |||
| Simon Quellen Field (Sfield) |
I'm glad you were psyched -- that's the goal ;-) The transmitter is deliberately low power, to stay within the rules set by the FCC in Part 15 of the FCC regulations. However, it is really easy to get a license to transmit at power levels that routinely and easily circle the globe. Some people use these licenses to bounce signals off the moon and back to earth, and to talk to space shuttle astronauts. The details on how to get a license are here. I have such a license -- my call letters are AB6NY. There are many FM transmitter circuits on the web. Do a Google search for "FM transmitter circuit". Some use only a single transistor. They are not as easy as the AM transmitter, but not much harder. To increase the range of your AM transmitter legally, you can run a wire around your house (perhaps tacked to the eaves just under the roof. Your transmitter should then be able to reach every room in the house, and yet still not bother the neighbors. A battery with a higher voltage would just damage the oscillator. A battery with more ampere-hours would last longer, but would not extend the range. | |||
| Anonymous |
Is it possible to connect the antenna to a running electric fence without damaging the transmitter? What about is it hard to get a license with the FCC to transmit AM signals as a radio station? If so, How? I would like to have a radio station, and I was wondering how to make it legal! | |||
| Simon Quellen Field (Sfield) |
It is really easy to get an FCC license to transmit on a radio. See the link in the previous message. If the transmitter is battery powered, you should be able to connect the antenna to the hot fence without trouble. Just make sure that nothing in the transmitter ever touches anything connected to the ground. You also don't want to touch the transmitter while the fence is hot, as the resulting jolt will surprise you, and most likely fry the transmitter completely. Getting a license to broadcast a radio show is not as easy as getting an amateur license to talk to other amateurs in the short wave bands. The main impediment is money. In the amateur bands, the license costs less than the transmitter, and the fee is basically just there to pay for the paperwork. But the big advantage of using the amateur bands is that you can send your signal anywhere on the globe, and even talk to astronauts (most of whom have amateur radio licenses themselves). A list of astronauts with amateur radio licenses is here. Some other amateur radio operators you might know are Marlon Brando, Juan Carlos (the King of Spain), Priscilla Presley, Kevin Mitnick, Dick Rutan, Jeana Yeager, Joe Walsh, Patty Loveless, Ronnie Milsap, Chet Atkins, George Pataki, Walter Cronkite, and many others. If some of those names are not familiar, do a Google search on them. | |||
| Anonymous |
Thanks | |||
| Pat |
Hi I am looking for a middle school project is the 3 penny radio a good project for my dfaghter who is 13 | |||
| Simon Quellen Field (Sfield) |
I think 13 is old enough for soldering. My daughter loved to solder at about age 8. Watching the solder melt into a puddle was fascinating for her. The project itself (building a radio) is certainly something a 13 year old can understand and get to work. | |||
| Anonymous |
I have two questions. Maybe you can help. How much current can a serial port supply at 5 volts? If you draw too much current from the port can you burn it out? Thanks. | |||
| Simon Quellen Field (Sfield) |
You can short out a serial port without damaging it. The serial port puts out more than 5 volts (over 20 on one pin and -20 on the other, for more than 40 if the two are used together, but the levels are allowed to go as low as 3 volts and - 3 volts). How much current you can draw will depend on how much current the port can source. This is not much (otherwise you couldn't short it out without damaging something). The best source of information on serial ports I have found is Jan Axelson's "Serial Port Complete". | |||
| aad |
I would like to built a FM radio and use a potato or two cans of coca cola as the energy scource to run the radio. The potato as an energy scource is well known and I also realize the potato will not give more than 1.2 volts, while I need 6 volts for the radio. How can I solve this? Aad | |||
| Simon Quellen Field (Sfield) |
The main problem with the potato battery is the number of watts you can get, not the voltage (since you can add batteries in series to get more voltage). A watt is a volt times an ampere. The voltage of a potato battery will depend on the metals you use (such as iron and copper, or zinc and copper) and the number of cells you have in series. The amperage will depend on the surface area of the metal electrodes, and the number of batteries you have in parallel. Most of the devices that run on a potato are things like digital clocks, which have very modest current requirements (microamperes). Radios need power to move the air in your ear canal. The homemade batteries I show in the Three Penny Radio project use stainless steel and aluminum for electrodes, and the surface area is considerable, since the entire bowl is the electrode. It would take a lot of potatoes to match that. | |||
| Anonymous |
What is the easiest way to build an FM transmiter? I would also like to know if I can broadcast using it without a licence. If I do need a licence, where do I get one in Ireland? | |||
| Simon Quellen Field (Sfield) |
In the U.S., it is allowed to transmit in any band if you keep the power low and the antenna small. In Ireland, things may be different -- check with your local Amateur Radio club. If you do a Google search for "FM Transmitter Circuit" you will find lots and lots of simple transmitters. | |||
| hatem elborai |
I am trying to find a circuit layout, with component detail for electric fence | |||
| Simon Quellen Field (Sfield) |
You can try here. | |||
| Anonymous |
can anyone help, i need to make a battery charger that charges of a 12vdc power source(small motor) to charge a 6-12v battery but i cant find any circuits | |||
| Simon Quellen Field (sfield) New member Username: sfield Post Number: 14 Registered: 12-2004 |
Just connect the positive lead of the motor to the positive terminal of the battery, and the negative lead to the negative terminal. Current will flow from the side that has the higher voltage to the side that has the lower voltage. | |||
| Anonymous |
now lets say ive done this part would you be able to tell me how to connet some sort of indicator to tell me if its charging cause i pulled a display off an electric razor and i was wondering would that work, if its too complicated to explain dont worry about it, and thanks for the other help | |||
| Simon Quellen Field (sfield) New member Username: sfield Post Number: 19 Registered: 12-2004 |
Place a voltmeter across the terminals of the battery. When the battery is charged to 12 volts, the meter will read 12 volts. | |||
| Anonymous |
now i need to draw a circuit and i can do so now with the info you gave me but can you tell me what type of battery to put in my circuit and thanks again for saving my skin | |||
| Simon Quellen Field (sfield) New member Username: sfield Post Number: 21 Registered: 12-2004 |
You can just use a block labeled "12 volts", with one positive and one negative terminal. That will do for either a battery or a power supply. | |||
| Adam Ryan Unregistered guest |
I am looking to build a variable power supply. I have a 10 amp 24V (from 240V) transformer gathering dust and I have made a variable power supply in the past based around a Motorola LM317K three terminal regulator. I want to use a pass transistor such as a 2N3055 or MP2955(?)in a TO3 package so as to be able to realize a voltage of between 1.2 to 20 volts or so, and 8A or more. Is there a circuit for such a device ? | |||
| kameshwar roa Unregistered guest |
i want some motor to play it. | |||
| Simon Quellen Field (sfield) New member Username: sfield Post Number: 193 Registered: 12-2004 |
I don't know what that means. Please describe your problem in much more detail. | |||
| Anonymous |
how do you make a battery using vinegar. | |||
| Simon Quellen Field (sfield) New member Username: sfield Post Number: 229 Registered: 12-2004 |
See the Three Penny Radio project. | |||
| John P Becich (johnpeter) New member Username: johnpeter Post Number: 1 Registered: 4-2005 |
My son has purchased about three kits for making wirless an AM transmitter, receiver, etc. The wireless AM transmitter depends upon modulation of 9VDC, which is supplied as Vcc at the HKT-14F 1.000 MHz xtal oscillator. I like the design, but I'm skeptical because I suspect that 9V exceeds the absolute maximum voltage allowed at the power pin of this oscillator. I Googled HKT and got a Korean link, but I can't seem to e-mail them for a specification sheet. Can you supply a spec sheet? Can you at least inform me of the maximum Vcc permissible? I have other power supplies, so I'd really like to know just how much voltage is permissible at this device. Thanks! | |||
| Simon Quellen Field (sfield) Senior Member Username: sfield Post Number: 344 Registered: 12-2004 |
It's a CMOS oscillator, and can handle about 10 volts before it turns off and stops oscillating. The overvoltage doesn't seem to do any damage, so there may be an overvoltage protection in the circuit, by design or by accident. After putting 12 volts in and getting no oscillation and no heating, I went back to 9 and it worked fine again. The spec sheet will tell you the limit is 5 volts. We aren't using it for its intended purpose. Our use is out of spec, like oveclocking a processor. | |||
| John P Becich (johnpeter) New member Username: johnpeter Post Number: 2 Registered: 4-2005 |
Thanks for your timely reply. It's nice to know we are not entirely "on our own" with these kits. Your experience speaks volumes. I have cannibalized an old Dell computer for its "ATX" power supply. I found a pinout diagram and got the thing to work. BTW, Dell uses the ATX form factor for this p/s, but imposes a proprietary wiring standard at the motherboard connector. Therefore, my son will have abundant and filtered +5VDC, as well as +/- 12VDC for his projects. Do you suppose this wireless AM transmitter will work at +5VDC, instead of +9VDC? I cannot imagine why not. If you feel your other readers would benefit by using a power supply in this fashion, I can post more details. Let me know at your convenience. | |||
| Simon Quellen Field (sfield) Senior Member Username: sfield Post Number: 345 Registered: 12-2004 |
The range will be about half as far with 5 volts as with a 9 volt battery. And yes!, we encourage everyone to post their projects on the message board so others can benefit. | |||
| John P Becich (johnpeter) New member Username: johnpeter Post Number: 3 Registered: 4-2005 |
We are pleased to say that our AM transmitter worked. We powered it with +5VDC, from a recycled computer power supply. The range of this transmitter was perhaps one foot. We used a transistor radio as receiver. The receiver could be plugged into the wall (117VAC); it also has batteries. Importantly, reception was unchanged when we removed wall power and allowed the receiver to operate on batteries. This eliminated the possibility that transmission was occurring by "conduction" rather than "radiation." I realize this concern would not occur to experimenters who power their transmitters by battery. Importantly, we used an old AM radio antenna as our transmitter's antenna. This antenna is of unknown length, as it is nearly coiled flat to the pressboard back of an long-gone table-top radio. We are tempted to unravel the antenna just to measure its length. However, that is very unlikely. We took a second, identical anteanna, and connected it to the ground of our transmitter, which was already grounded through the "green ground" safety ground of our power supply, to the house wiring. Understanding that green safety grounds have high inductance, and therefore constitute poor high-frequency grounds, I thought that the transmitter might work more powerfully if we installed a second antenna, to the grounding post, so as to construct a dipole antenna of sorts. This turned out to be ineffectual. In case anyone is interested in how my son and I constructed a fine prototyping station out of a discarded computer, I am willing to post pictures. Here is a hint:  I have detailed pictures, with inset text, but feel that they should lie in a dedicated thread, if anyone is interested. I don't know how to start a new thread. | |||
| John P Becich (johnpeter) Junior Member Username: johnpeter Post Number: 4 Registered: 4-2005 |
Oops. Typo. Said "nearly coiled flat" but meant that to read "neatly coiled flat." | |||
| Anonymous |
That power supply looks really cool. I have an old computer lying in my room, and have been wanting a power supply for some time. Please, by all means, please do put up pictures & instructions. Although I think it would be fine for you to put them on this thread, here's how to start a new one: On the page displaying topics, pick the one you think it should go under. Click it. There is a list of threads. At the bottom, there is a link, "Start new thread." Click, and proceed as desired. Looks cool! Please post soon :-)! | |||
| Anonymous |
Simon, it appears that our friend, Mr. Becich, is not responding. Do you know anything about how to make this project? Thnx! | |||
| Simon Quellen Field (sfield) Senior Member Username: sfield Post Number: 379 Registered: 12-2004 |
It's really simple. The computer power supply puts out +12, -12, and +5 volts on the connectors. You plug it in, and connect it to what you want to power. | |||
| Anonymous |
Ok, sweet! Thanks! | |||
| Alessandro Carcione (alessandro) Junior Member Username: alessandro Post Number: 33 Registered: 2-2005 |
Its not thAT simple, computer power supplies stay is standby mode if you just plug it in, in which they output about 3v, you need to short out two wires, a green and gray, they should be on the motherboard connector, this is the same as pressing the on button on your pc, you should then hear the fan power up. The power supply is now on and should be able to draw full voltage from it | |||
| John P Becich (johnpeter) Junior Member Username: johnpeter Post Number: 7 Registered: 4-2005 |
Sorry for the prolonged absence. I was away on business...and then Mother's Day took precedence. I'll attempt to start a new thread, per your instructions. I'll call it something like, "Development platform uses old computer power supply." | |||
| QUISHA (Unregistered Guest) Unregistered guest Posted From: 206.9.80.3 |
do you guys kown what you are DOING FROM? | |||
| M.E.W. (Unregistered Guest) Unregistered guest Posted From: 66.4.125.11 |
Ok I've been wanting to get into radeo for some time now and was wondering what the biggest legal transmitter is without a licence and with that amitures licence mentioned earler in the page. I have an electric fence that I could use as an antena and an old computer power suply and i have acess to a radeo shack. | |||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 787 Registered: 12-2004 |
Assuming you live in the U.S., the regulations governing antenna size and transmitted power for unlicensed operators are covered in Part 15 of the FCC regulations. | |||
| apollo (Unregistered Guest) Unregistered guest Posted From: 12.214.202.226 |
I really want sparks bigger than 1 inch for my leydon jar. What do i do? | |||
| James Lee (Necrofear) Member Username: Necrofear Post Number: 19 Registered: 8-2006 |
What sparks are you looking for?? You need to ask more specificly | |||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 1451 Registered: 12-2004 |
The length of the spark is limited by the voltage. Raise the voltage. If the voltage exceeds the abilities of the capacitor (Leiden jar -- please spell it right so people can search for it) then you will need to improve the capacitor by making the glass thicker. This will decrease the capacitance, so you will also need a bigger jar. | |||
| Jacob Chacko (Unregistered Guest) Unregistered guest Posted From: 58.68.87.102 |
Can anyone tell me what is the average range of this AM transmitter. Say i'm using a 1m TX antenna. Also i was unable to get my hands on the HKT-14F 1MHz oscillator. I got another oscillator of the same frequency.(KDS) . Do all these osciallators have the same pin configuration, and will i be able to use it as an AM transmitter? | |||
| Ahshan Contractor (Unregistered Guest) Unregistered guest Posted From: 71.30.181.242 |
Hmm, well im building a computer controlled am transmitter, and i need a 1mhz crystal oscillator, and fast. I was wondering if there is any store close to me that sells them, my zip code is 77083 | |||
| James (Teamsr195) New member Username: Teamsr195 Post Number: 2 Registered: 7-2007 |
I am trying to build a motor that will run on a cable. I need the motor to be able to support about 10 pounds with a variable speed control. I would like to be able to run a max of about 15 mph. Also once the pully reaches the end of the cable I need it to have a switch that will trip and reverse the polarity so it will go forward and reverse. What do I need to make this work? I have a basic idea but have never built anything like this before.
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| Shivam bhatnagar (James) New member Username: James Post Number: 1 Registered: 5-2009 |
To make a gauss gun, can you suggest any other magnet other than neodymium magnets ? | |||
| J N (Newty) Junior Member Username: Newty Post Number: 4 Registered: 5-2009 |
No offense to SQF, but he is only one guy. You can get answers a lot faster by asking them on Instructables Answers. It's like Yahoo answers, only it has some actual scientists, crafters, cooks, and other experts answering your questions, rather than moody teenagers. http://www.instructables.com | |||
| Theresa Simmons (Theresa) Senior Member Username: Theresa Post Number: 128 Registered: 1-2008 |
The strength to mass ratio is very important for the Gauss Rifle. The magnets should be the same mass as the balls, and should be as powerful as you can get for the mass. At the moment, that means neodymium-iron-boron magnets. Magnets that are bigger are more powerful, but then you would have to make the balls bigger to match, and they would not go any faster. So using a magnet that has a lower strength to mass ratio will be disappointing. You really want the strongest magnets you can get. The magnets at scitoys.com are N52 -- currently the strongest available (52 mega-gauss-oersteds). | |||
| Chuck McManis (Cmcmanis) New member Username: Cmcmanis Post Number: 1 Registered: 9-2009 |
I thought I would post a link to my EELB project (http://www.mcmanis.com/chuck/Robotics/projects/eelb.html) which was inspired by Simon's radio, it adds a simply micro-processor and sends morse code. Recently the kids were interested in some Leydon jars. We read the Maker's article and looked at the foil carpet tape they suggested but its not conductive. This turns out to be both good, and bad. If you want to join two pieces conductively you can punch a hole in one, stick it to the other and then tape a conductor across the hole. Aluminum foil works but am a bit worried about oxidation over time. Love the site as usual, --Chuck | |||
| Patrick (Firewire) Senior Member Username: Firewire Post Number: 135 Registered: 12-2007 |
If oxidation is what you're worried about then you could paint the entire jar with an epoxy based paint (usually on spray paints, acrylic based paints would have a powdery texture) so the outside will have a smooth thick coat of paint. Not only will it prevent the foil from oxidizing, but it will also reduce leaks from the foil thus sustain the charge a little bit longer than without the paint. |
diagram