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BS & MA Physics, I enjoy electronics, ham radio, scanning, building antennas & circuits, repairing things mostly electronic but toys for the kids, bikes, cars, whatever, playing guitar as well as oil painting when I can find even more time, ha!

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  • Illuminate Lightbulbs Wirelessly: DIY Slayer Exciter

    I love these wireless ideas and experiments, nice job!However, when we do things wirelessly we pay a price. In general it costs more in power, and thus money, to do things wirelessly than it does with wires. This is mostly because of the inverse square law of power/signal transmission but also because the power goes everywhere and not just to the device that is using it.From the photo the power supply is running at 18.41 Volts and supplying 3.35 amps for a power of 61.67 Watts and a 60W equivalent CFL bulb generally takes about 15 Watts so for this one build we're back to using over 60W of power. This is assuming that the power supply pictured is in fact running your power transmitter. Now, if this device can power five or more 15W CFL bulbs we'll be saving energy, using less power than...see more »I love these wireless ideas and experiments, nice job!However, when we do things wirelessly we pay a price. In general it costs more in power, and thus money, to do things wirelessly than it does with wires. This is mostly because of the inverse square law of power/signal transmission but also because the power goes everywhere and not just to the device that is using it.From the photo the power supply is running at 18.41 Volts and supplying 3.35 amps for a power of 61.67 Watts and a 60W equivalent CFL bulb generally takes about 15 Watts so for this one build we're back to using over 60W of power. This is assuming that the power supply pictured is in fact running your power transmitter. Now, if this device can power five or more 15W CFL bulbs we'll be saving energy, using less power than plugging in five 15W CFL bulbs. Again assuming we'd only need the 61.67 Watt power transmitter.So first, how much power are you using to get that one bulb to light?What power rating is the CFL bulb you're using?Is the light produced at the same level as with a direct electrical connection? If not, is it brighter or dimmer and by what amount?Have you experimented to see how many bulbs and at what distance this works?Again, very nice I love it!

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  • PhilKE3FL commented on JunezRiyaz's instructable How to make a LED Flashlight1 month ago
    How to make a LED Flashlight

    A 12V, 10W LED means it needs ~833mA. A 9V battery is usually only used for ~ 100mA or less and at this discharge rate is rated at about 310mAH or it would last about 3 hours. See:http://www.powerstream.com/9V-Alkaline-tests.htmNow, at a 1A discharge, or power of 9W, close enough to run the 10W 12V LED. The above tests show a good alkaline 9V battery lasting about 0.09 hrs (90mAH/1000mA = 0.09 H) or about 5.4 minutes. The best would last 0.3 hrs (300mAH) or about 18 minutes.However, this is running the battery down to 0.1 Volts and most 9V applications run the battery down to about 5 or 6 Volts and a 12 V LED would probably turn off at about 6 Volts (this is just a guess I'd have to test one to be sure) and so in all probability the flashlight would last perhaps only seconds before runn...see more »A 12V, 10W LED means it needs ~833mA. A 9V battery is usually only used for ~ 100mA or less and at this discharge rate is rated at about 310mAH or it would last about 3 hours. See:http://www.powerstream.com/9V-Alkaline-tests.htmNow, at a 1A discharge, or power of 9W, close enough to run the 10W 12V LED. The above tests show a good alkaline 9V battery lasting about 0.09 hrs (90mAH/1000mA = 0.09 H) or about 5.4 minutes. The best would last 0.3 hrs (300mAH) or about 18 minutes.However, this is running the battery down to 0.1 Volts and most 9V applications run the battery down to about 5 or 6 Volts and a 12 V LED would probably turn off at about 6 Volts (this is just a guess I'd have to test one to be sure) and so in all probability the flashlight would last perhaps only seconds before running out of enough power to run the LED.Now, if you limit yourself to a 3V ultrabright white LED you can use "dead" 9V batteries ~ 4V without a resistor and get hours of use out of it. Been there, done that. If the 9V battery is at about 6V I use two 3V LEDs in series until it gets down to about 4V when I can use the same battery with one 3V LED.So how long does your 10W, 12V LED last on a small 9V battery?

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  • Practical Guide to LEDs 1 - Pick your LED!

    Sorry about that, "flit" should be flip, flip the LED & plug it in the other way to test it again to be sure it is not dead & you only had it in the wrong way for the first test.

    Thank-you LaurJ for the helpful physics information! I didn't know that and I've worked in both ElectroOptics & optics fields! I never even bothered to wonder why - my bad!

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  • ESP8266 EcoPlug Wifi Smart Outlet MQTT Mod for less than $15

    I don't know about others, but I for one would like to see EVERYONE who writes a HACK piece put right up front WHY they are doing this. What is it we will gain by doing this hack? I think that will save everyone time since those not interested can skip it and those who would be interested can find out up front that they are interested. Also, saying things like, "put jumpers: Ecoplug VCC to 3.3V on FT232..." as you've done above assumes that everyone doing this hack knows what you are talking about. I suspect that this is NOT the case and some photos and schematics with circles and arrows would come in very helpful for those not as familiar with the chips and board as you are.

    No argument there Raphango! Thanks to billm950 for doing it!

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  • Practical Guide to LEDs 1 - Pick your LED!

    Or, you can build a joule thief circuit with an open place for the LED. Mark it so you know which is + and which - then plug the unknown LED in & push the test button. If you have it correctly installed it will light up, if not it won't light, or it is dead so flit it around & try again to be sure. See my LED tester on my web site.http://cs.yrex.com/ke3fl/htm/LEDTester.htm

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  • PhilKE3FL commented on Srpska Nauka's instructable How to make a Joule Thief3 months ago
    How to make a Joule Thief

    Very nice, more info than most. I'm interested in the one that uses a 9V battery. What I have found is that no circuit is needed if the 9V battery is ~ 5V or less simply put the diode across it. Most ultra bright white LEDs are designed to work with 3V and will turn on ~ 2.5 or a bit less.You can see my experiments on my web site & I also explain how to pass the "simple" joule thief and make a more efficient version that uses less current so even you dead battery will last longer.My site is: http://cs.yrex.com/ke3fl and just click on the "Feature Article" link on that page. Then look for the, "Joule Thief Experiments" link.

    The Joule thief circuit in various forms is used to power things that require more voltage than you have available. Thus a "dead" 1.5 Volt battery at ~ 1 Volt can run an Ultra bright LED for days making a very nice little flash light. Been there done it. It can also be used to run other devices that require ~ 3V from a 1V battery adding a few more parts to filter the voltage and make it more DC. Look up my web page for additional links to such articles by others.

    There are many site to explain how this works but you can look at the experiments I've done on my site and how to make a simple Joule Thief more efficient, uses less current and from batteries even below 0.5Voltshttp://cs.yrex.com/ke3fl/htm/JouleThief/JouleThief...I have many links & the first one is to a Wiki article explaining the joule thief circuit.Enjoy!

    Oops, my web site is at: http://cs.yrex.com/ke3fl

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  • A Guide for Buying LED's on E Bay ---- Part TWO

    Been there done that too. Both using the bridge rectifier and building my own. I'm using two 1 Watt bulbs I build to sufficiently light up the basement hallway, two watts replaced 120 watts! Not quite as bright but very acceptable for this task.

    All of this is true and I added another diode, reverse direction, and a resistor but the original design worked for almost a year with only a small capacitor and the LED as either a night light, with an ultra bright LED, or using a lower level LED as an indicator light. At least two of the four original design indicator lights, to indicate that the outside lights were on, died in less than a year just from turning the light switch on and off. With the added reversed diode and the resistor none of the indicators have yet died now going on three+ years.

    No arguments from me on any of these points. My movement to LEDs was because of considering all of these points especially the safety issues with small active grandchildren about the house. I have also done measurements with a light meter to see what size bulb will do the job and found at times a 5 - 7 Watt LED bulb could replace a 23W CFL bulb. This is especially true when the light is needed in one basic direction instead of 360 degrees and the particular LED light is better for that than the CFL is.

    Quick note, normally LEDs are less efficient than this because of the circuitry added to drive the LEDs. That has also been one of my goals, to find the most efficient LED bulbs. The lower the Watts used to produce the light the better the efficiency. I've seen LED 60W equivalent bulbs using anything from 9.9W down to 7 Watts. You do NOT want to buy LED bulbs that use the same number of watts to produce the same number of Lumens as a CFL bulb otherwise you're not saving any money buying an LED bulb vs a CFL bulb.

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  • PhilKE3FL commented on Nematic!'s instructable DIY Power Bank ?5 months ago
    DIY Power Bank ?

    Very nice, might also want a step down converter and remember, some 18650 cells have built in current limiting and any up/down converter also has a current limit which may, or may not, limit the useful current even more.Oh, just a friendly word hint, the English language is a real "pain" we have many words that sound alike and are spelled differently and mean different things. A real good example is, to, too, and two for one. :) The word "Patient" is a person under a doctor's care. The word you wanted to use was "Patience" meaning a person is tolerant, able to handle disappointment and continue.Thanks again for posting your instructable! Also, your use of English is far better than mine would be of your language, please continue to post & expand you kno...see more »Very nice, might also want a step down converter and remember, some 18650 cells have built in current limiting and any up/down converter also has a current limit which may, or may not, limit the useful current even more.Oh, just a friendly word hint, the English language is a real "pain" we have many words that sound alike and are spelled differently and mean different things. A real good example is, to, too, and two for one. :) The word "Patient" is a person under a doctor's care. The word you wanted to use was "Patience" meaning a person is tolerant, able to handle disappointment and continue.Thanks again for posting your instructable! Also, your use of English is far better than mine would be of your language, please continue to post & expand you knowledge both of electronics and the painful English language. (Which most of us who speak English as a first language still mess up as well!)

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