Hi, I sell old money from my country, I'm looking for a collector who is interested in old money.
Topic by ninatief | last reply
Hey guys, I was just wondering if anyone here collected coins. My brother, and my dad, and I all collect coins as a side hobby. What coins do you collect? What types do you have, and the oldest ones? I have many books for nickels, dimes, and pennies. I just love the feeling when I can open up the book and find it full! My brother and I just bought some old Indian Head pennies, as well as some Steel Pennies from 1943. (During WWII) I have many foregin coins, as well as about 20 Susan B. Anthony's. I have about 10 Sacajawea coins, and a few Kennedy Half-Dollars. I just love the feeling of the profit that will be made in the future. Today I collected about 6 brand new 2007 Pennies, and took them out of circulation. Share your tips, tricks, and cool places to find your coins! As well as your coin collections!
Topic by Brennn10 | last reply
Does anyone know of some instructions to make a leather type cap with magnification glass or strange levers protruding out of it? I'd like to make something "weird-scientist"-like for my entomologist friend, Thanks! edited to spell "bug guy" correctly
Topic by Oakherder | last reply
I have salvaged 2 car radiators that are old yet not leaky. I want to use them for active closed loop solar collectors. Any advice?
Question | last reply
Oneida and other companies make a dust separator that uses cyclone action to separate the chips and dust from the airstream before it gets to the dust collector and clogs the filter. Has anyone done an instrucable showing how to build something like this?
Question by rmelchiori | last reply
This has been an ongoing saga for the last six months or so, but with a lot of help from many of you here the Sunflower prototype is finished. And it works! It still needs perfecting, but the principle is sound.This unit cost me less than $20, is almost entirely recycled and salvaged materials, was ridiculously easy to make (tho since I've thought of a way to make it much simpler) and seems to work fairly well. With a larger collector and light pipe in place this unit alone could collect up to a kilowatt of power, maybe more. Now I need to start working on the Mk II perfected design, and some applications for electricity generation and water purification.This will be an ongoing open source project. Once I've got a design which is nice I'll get a website up and be traveling round working with local community groups, inventors and NGOs.If you have any desire whatsoever to take a crack at making this yourself please please do so. The video is a little light on the finer details, so if there are any questions just ask.And thanks again for all those who helped out.
Topic by SolarFlower_org | last reply
I'm a wildlife biologist currently between jobs, so my budget for new cool gear like the iRobot Create is pretty much nil. But I have an idea for using the Create as a prototype platform for a field-usable device. Previous work has established the utility of robotics in obtaining data concerning wildlife behavior (e.g., Patricelli, G. L., J. A. C. Uy, et al. (2006). "Interactive signaling during mate choice in the Satin Bowerbird: an experimental test using robotic females." Journal of Ornithology 147(5): 12-12.) My background has included electrical engineering, computer programming, and bioacoustics. What I would be interested in trying my hand at is using the iRobot Create to set up an autonomous robot to localize sound, orient toward it, approach, and obtain sound recordings. I believe that this an achievable project in the contest timeframe. I already have microphones and amplifiers suitable for the project. I can either use three or more in a planar array to use time-of-arrival for sound localization, or use material to make each sensor directional and calculate heading from amplitude differences. In any case, the sound sensors would be used to obtain heading information for the robot. Acoustics boils down to a simple dictum: get a good microphone close to your subject. In this case, a robotic platform stands a much better chance of approaching wildlife without causing the sort of disturbance the presence of a human observer usually makes. While the Create platform itself may not be suitable for field deployment, I think that it would make a good prototype for lab testing of the concept. In that light, I will probably use a voice recorder as a lightweight recording system that will only require two actuators to have the robot operate it. There are some additional considerations that I will need to explore, such as figuring out how to determine closeness of approach. This would eventually need to be based upon calculations of whether the robot is at the boundary of far and near-fields of an acoustic source at the highest frequency of interest. That would maximize the sound amplitude at the recorder without the interference that is the defining characteristic of the near-field regime. If the prototype works well, there are further ideas that could go into a field robot system. One would be to have the robot localize a source and conduct a survey, carrying a GPS mapping system while taking sound recordings with a calibrated sound recording system. This would be useful to characterize sound propagation properties of the animal's emitted sound. As in Patricelli's work, the field system could be disguised as a conspecific, or at least a species that is likely to be considered "harmless" by the subject.
Topic by Diane Blackwood | last reply
I am installing a cyclone dust collector in my workshop, and I want to make a sensor that will determine when my dust bin is full so that the chips and dust won't overflow into the filters. I'm thinking garage door sensors could be blocked by sawdust rising into the transparent flex hose between the cyclone and bin, but I'm not sure how they work. I would use them to turn on a warning light and turn off the dust collector. Any ideas? I'm good with tinkering and basic electricity, but am stuck trying to figure this out.
Question by woodwringer | last reply
I have seen solar collectors with a black pipe inside a vacuum tube like these Ebay Tube I want to know if this needs a complete vacuum or will a semi-vacuum work just as well, or at least help. Will even the smallest amount of air eliminate any benefit.
Question by jj.inc | last reply
I have salvaged 2 car radiators, they aren't leaky. I want to use them for active closed loop solar collectors. Any advice? My current plan is to put them on the roof (in a hot box), then plumb them into an old water heater in the attic. My hope is they can recirculate glycol in a closed loop, convection only, but I may need to install a thermostat and pump. Anyone have experience in this? I want to dump the heat to my 2 water heaters in the basement (they are plumbed in tandem, so I can use the 1st tank for solar boost and 2nd tank for final temperature control). Heat exchangers: either the Butler Solar Wand, or Brazed Plate Heat Exchanger (single or parallel). Differential Temperature Controller from www.jc-solarhomes.com. Any advice or suggestions hugely welcome. thanks in advance, Chris
Question | last reply
Hey instructables community, I have 3 vintage cameras for sale and you can view them at the following links. http://austin.craigslist.org/pho/2631541962.html. http://austin.craigslist.org/pho/2631541693.html. http://austin.craigslist.org/pho/2631541304.html. I am willing to ship across the country (United States) and to the U.K. (you must pay for shipping separately). I am also willing to accept any reasonable offers. Please P.M. me if you have any questions, or if you are interested. Thanks AcidBass
Topic by acidbass
What makes collector current to be beeta(current amplification factor) times base current? Is it because of shape of the transistor or doping? or Why it is acting as constant current source? or Why the collector current is independent on collector resistor and Vcc(voltage across collector and emitter)?
Question by deepakmurali | last reply
What simple tools can i use to build solar collector?
Question by bernardshalom | last reply
The bottom of the pool is the coldest water so why not heat it from there. what would be a good black material that would sink, absorb energy from the sun and transmit it as heat to the surrounding area. would this not create a method of convection current heating?
Question | last reply
A normal oscillator will provide 360degree phase shift. of this 180degree is by the transistor amplifier and the remaining 180 is by the feedback circuit or tank circuit. but in the case of a pierce crystal oscillator ,it is the crystal which connected across the collector(output) and base provides 180degree phase shift the crystal provide 180degree phase ?
Question by mishal.abe
Can the minimum collector emiter sustaining voltage of a transistor be more than the power supply voltage or is that somthing else? For example can I run a transistor with a minimum collector emmiter sustaining voltage of 100 with a 12 volt power supply ? Thanks
Question by build a BOOM | last reply
Http://www.nintendo.com/games/detail/7y8SXfbq4nlR_ZO15BY3yHdKL7erLAnkI would really like to know bacause I am getting it.
Question by nerd7473 | last reply
Looking at this data sheet: http://www.datasheetcatalog.org/datasheet/stmicroelectronics/4136.pdf How much voltage has to be applied across the base and emitter to switch on a "TIP 3055" transistor? The V-be row is the only thing that looks like it is telling about that, but I don't think that's what I'm looking for (mabey it is?).
Question by Jaycub | last reply
The best i can figure, the current coming through toroid turns on the transistor, then the collector drains the current to the negative, while pulling it from the emiter back through the diode to the collector? if i am correct, how would this boost the voltage?
Question by revelae | last reply
I am constructing the flyback driver found on the power labs website and cant get a 2N3055 transistor quite yet. I do, however, have a bag of transistors i pulled out of CRT monitors. I was wondering if one would be a good substitute for the 2N3055 for driving a new flyback, the number is C4916, the base-collector voltage is 1500 V and the Collector current is 7 Amp
Question by budhaztm | last reply
Hi I need help to write a program for an Arduino to allow it to function as a Solar Differential Controller (SDC). An SDC simultaneously reads the temperature of two different elements,1) the water inside the thermal storage tank and 2) the inside of the solar collector. When the sun rises in the morning it begins to heat up the inside of the collector. When the SDC senses that the collector is a few degrees warmer than the storage tank it signals a circulation pump to turn on to circulate water from the tank, through the collectors and back to the tank. When the sun starts to set in the evening and the collector cools to within a few degrees of the storage tank, it signals the pump to shut off. So basicly I need the Arduino mega 2560 to read the temperature from two DS18B20 digital temperature probes. When one of the probes shows a reading 5oC higher than the other, the Arduino changes an output to high. When the higher probe's reading drops to within 5oC of the lower one, the Arduino changes the output back to low. I don't even know where to start really, this programming is way over my head. Any help would be appreciated. This program is for a large project I'm working on for this site and any help you give me will be credited to you. Thanks.
Question by EcoMotive | last reply
Hello EveryoneWhile iam connecting a motor of ratings 3v ,300milli amps in the emitter side it is drawing around 200 amps ,whereas when iam connecting it in emitter leg it is drawing 200ma,but in collector leg it is taking 300mamps,1kohm resistor is connected to base and 10ohm resistor to collector and supply voltage is 5v but as per bjt emitter leg is the one which will draw more amps,then why this behaviour??
Question by Freak07 | last reply
I have a dust collector in the form of a Playstation 1. Anyone have any ideas for something cool to do with it?
Question by brandegor | last reply
Hello .I'm having some some problems with my current project .Can you guys help me please ! This is the schematic of MXR headphone amp for guitar .I don't have 2n4401 and 2n4403 , so i replace them with 2n3904 and 2n3906.The result is output is too low .2n4401 and 2n4403 (collector current = 600mA) ,2n3904 and 2n3906 (collector current = 200mA).If i replace the transistor with higher Ic i will have louder output ??? http://i247.photobucket.com/albums/gg132/chipmapple/mxrheadphoneampschematic.gif Thanks for advance! Sorry for my bad English!
Question by login721 | last reply
Just in case you guys don't hang out in Green.If you're lazy:https://www.instructables.com/community/Finally-finished-my-solar-collector-prototype/
Topic by SolarFlower_org
Hi everyone, I'm new, from the UK, I will shortly be moving into a static caravan/mobile home on family land for a few years to save up, so with money saving being the aim, I'd like to run this little project by you all. I'm thinking about making a solar collector and placing it on the roof of the home, as large as I can afford (caravan is 12 wide) and feeding that into a heat exchanger inside an old 47kg LPG gas cylinder (I have access to several old cylinders and believe it can hold around 110 litres, so could even use 2?) and having the mains inlet at the bottom and outlet to the boiler at the top. For the heat exchanger, I'm thinking cut both ends off and drop a coil through from top to bottom and weld back up but i'm open to suggestions. I want to a heat exchanger instead of having the mains water go round the solar collector, as it can get cold in the UK at night, even in the summer and I dont want it freezing in the winter (i'll have enough worry of water pipes freezing anyway), so will use some form of copper friendly anti-freeze. I'll need a pump for this, as the collector will be on the roof, above the cylinder, so thinking to run it on a light sensor, but how complicated would a thermal switch be, so when the temp in the collector ir warmer then the cylinder be to make? If anyone knows of a place for the circuits (or of the shelf product), I can see if it's something i'm competent enough to take on. One last thing, Would having the cylinder painter black and left in sunlight be a good idea. Would it get hot enough to cause problems with the water mains pressure? Look forward to your feedback and advise. Tuns
Question by tuns | last reply
Check out this graphic of concentrated solar collectors on Saul's new skateboard. My first skateboard had a dragon sitting on top of a pile of human skulls. We've come along way, I guess.
Topic by ewilhelm | last reply
Hello All, I have a problem with a circuit i am building, I use a 2N2222 transistor to drive a Common Cathode big 7 Segment with a 595 shift register.. I connected a 12v to Emitter, the collector out a 4.7 volts !! How is this possible ? could some one explain please ? Thanks all
Question by EZELab | last reply
I am making a solar still and I need to recover as much heat as I can from the 130 degree F water (bringing the water temp down to near ambient, 72 degrees F) and then transfer this heat to 140 degree F seawater. I have a limited amount of solar collectors to heat brackish water, send it through an evaporator tower and then a condenser tower to make fresh water. As the fresh water goes through the condenser it gains a great deal of latent heat, thus the 130 degree F water. In order to increase production and regain otherwise lost energy I am trying to recapture a portion of this heat to further warm up the brackish water (currently at 140 degrees after exiting the evaporator tower) before being further heated with the solar collectors. I am operating off grid, so the solution must utilize solar heat or PV panels as the power source. Does anyone know of a heat pump that operates best in this temp range? What about using TEC (aka TEG, TEP or TEHP) to perform this task? Is there a better or more obvious solution that I am oblivious to? Any advice would be much appreciated.
Question by MichaelMichael | last reply
E-waste collectors in countries like Ghana collect cables and then burn them to get rid of the plastic and then sell the copper. This process is not environmental friendly and harms their health. I'm working on a project to find better ways to treat imported e-waste. Is there a better way to strip cables that would not imply burning, and that would respect the worker's health? Thanks!
Question by rf.font | last reply
Is it possible to make a self powered solar/battery usb bluetooth dongle? Would a solar collector from a solar calculator provide enough power to energize the bluetooth dongle? I have a simple flexible usb keyboard that I would like to use with my htc smartphone. How do I add a usb bluetooth dongle to the keyboard.
Question by wscottc60 | last reply
I have for some weeks been researching to find the schematic for a 2 input TTL OR Gate with Totem Pole Output (versus the Open Collector variety). However, I have had little success in finding the schematic. It was suggested that I try the Forum to resolve my problem. Therefore, can someone either provide a reference that shows the schematic or draw one? Thanks.
Question by ElectroZapper | last reply
Home Energy Monitor Reduce Your Impact Earth Day The California Cooler Build a 60 Watt Solar Panel Start a Community Garden Composting Energy Efficient Home Design Ride Your Bike in Style Solar Water Heater Geodesic Dome Greenhouse Energy Saving Vertical Axis Wind Turbine Pallet Compost Bin Rain Water Collector
Topic by randofo
Low-Footprint Lamp DIY Wind Turbine Energy Usage Monitor Build a Solar Tracker Stationary Bike Power Garden Rain Barrels DIY Solar Panel Recycled Window Greenhouse Pringles Wind Turbine Bike Wheel Generator Home Solar Panels Homemade Sun Jar Water Flow Sensor Solar Thermal Collector Energy Saving Tools
Topic by randofo
Ok I have the following Tech Deck boards new in package with all the trimmings. What I want to know is how do you tell when they were produced or made. I have the ones as follows, Baker, Blind Dark Star, Finesse, Flip, Foundation, Plan B, Powell and toymaker. I dont know what to do with them. over 200 packages.
Question by collector | last reply
Bubble Machine Two-Ingredient Ice Cream Laser Cut Wedding Dress Secret Minesweeper Pillows Simple Workbench Sleek iPad Stand Special Effects Makeup USB Game Pad Alcohol Stoves DIY Boom Box Desktop Skee Ball Make Viking Era Paint Altoids Stereo Mixer RFID Car Immobiliser Solar Hot Air Collector
Topic by randofo
Please there is this audio amplifier i have been working on, but have not been successful with it. i did check to make sure all my connections are OK. but what i am confused about is " dose it matter witch direction i connect my resistors" secondly "does it matter if i connect the resistor directly on the transistor collector arm or those it make the same if i use wires to make a longer connection? thanks. can anyone help?
Question by RdNard | last reply
Under saturation condition base current is very large that voltage across Base-emitter junction of silicon based BJT is more than 0.7 volt. In this condition the voltage at collector (Vc) is 0.2 volt. By kirchoff's voltage law Vc=Vce( imagine emitter is directly grounded) Vce =Vcb+Vbe. If Vbe>0.7volt how Vce=0.2volt? As Vce includes Vbe, it must also be more than 0.7 volt. But it is 0.2 volt wich is less that 0.7 volt. How?
Question by deepakmurali | last reply
Hello, i had an idea today. A light powered by a solar panel that powers itself! You would need a small amount of energy to initiate the circuit's current, but i can only see one way why this could not work: Lightbulbs lose some energy as heat and a tiny percentage as sound. How could you counter this? Heat collectors? Any ideas? I think that I may be on to something here!
Question by The Jamalam | last reply