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novelty led blinker, how is it done?

Discussion in 'LEDs and Optoelectronics' started by CABBAGE, Mar 28, 2019.

  1. CABBAGE

    CABBAGE

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    Nov 17, 2018
    Hello novice hobbyist here looking for the right component(s) or circuit to control a few led's with button batteries and have them blink randomly, can anybody help? for instance a four leaf clover pin with led's in the petals. I would like to make it motion activated and can't figure out the right configuration, do I need an accelerometer? a piezoelectric accelerometer? second is the random flashing can that be controlled with a 4017 IC perhaps? If anyone can point me to a simple circuit, it would be greatly appreciated. Or is there a simpler way? accelerometers are not cheap. I would like to find a simple less expensive way so I might make many and set them in epoxy. any and all help is appreciated, thanks in advance. C
     
  2. hevans1944

    hevans1944 Hop - AC8NS

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    Jun 21, 2012
    You need to visit this website and learn about PIR motion sensors. Then add a small microprocessor, such as a PIC made and sold by Microchip, with a program you write that creates pseudo-random activation of your shamrock LEDs after motion is detected by the PIR sensor. Easy peasy. You should be up an running in about a month or so. Be sure to purchase PICs in DIP packages for easy bread-boarding. You can convert to surface mount devices (SMDs) to miniaturize your project to a lapel button size later.
     
  3. Audioguru

    Audioguru

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    Sep 24, 2016
    Button batteries have a very small amount of chemicals so they light LEDs for only a few minutes, dimming all the short time.
     
  4. hevans1944

    hevans1944 Hop - AC8NS

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    That's why you need a PIC microcontroller... the LEDs are only briefly "flashed" to minimize their energy consumption. A few years ago at a Dayton Hamvention an antenna tower vendor was giving away stickers with a red LED mounted at the top of the image of a tower printed on the sticker. The LED flashed briefly every few seconds. They were powered by what appeared to be a "hearing aid battery" but there was no on/off switch. The user pulled a slip of paper from under the battery, allowing the battery to make contact with the cell holder and activate the circuitry. I grabbed a handful of them and took them home for further investigation. After activation, they would flash for about a week before the battery was depleted. I think @CABBAGE could implement a similar functionality with a PIC and a little programming effort. This would be a good introduction to circuit designs based around one or more PIC microcontrollers.
     
  5. Audioguru

    Audioguru

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    Sep 24, 2016
    Years ago, I made some LED chasers. I used high current Cmos 4017 ICs called 74HC4017 and a Cmos inverters IC making the oscillator and the mono-stable momentary blink from each LED. Two AA battery cells last for 3 months blinking day and night.
    10 LEDs blink around the circle in about 4 seconds and each blink lasts 30ms so that our vision does not see dimming.
    The current in each LED is about 20mA.
     
    hevans1944 likes this.
  6. hevans1944

    hevans1944 Hop - AC8NS

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    See what you can do to extend battery life by limiting the on time (short duty cycle) and the forward LED current? Having two AA cells helped a lot, but that's not cheating. The OP needs to learn about project power requirements and energy capacities of various storage devices before stepping off into the deep end of the pool. Only then can a realistic and practical design ensue.

    I was wrong in my recollection of how the "tower flasher" handout worked. I found one of them, with two dead batteries installed. They operate from two PR41/p312 1.4 V zinc-air hearing aid cells, of which I "inherited" a boatload after my brother died June 11, 2016. I didn't even know my brother wore a hearing aid, but I guess the VA supplied him with a whole lot of power cells on a regular basis. I wonder if Medicare would do the same for me if I had a hearing aid?

    Anyhoo, the device does have a tactile on/off dome-type switch, some sort of microprocessor in a chip-on-board (COB) design with an epoxy blob on top, several itsy bitsy teeny weeny SMD passive components, and a verrry small but relatively bright red LED, all surface-mounted on a round PCB about an inch in diameter with copper on only one side. There are four through-holes drilled to accommodate the prongs on the two cell holders and one hole to allow the LED to peek through, but the prongs and the LED are soldered on the surface-mount side of the PCB.

    This looks to be a pretty expensive freebie for a typical trade-show handout, which tend to be cheap ball-point pens and key chains and such with logos printed thereon... but maybe not. It was obviously designed to be stuck to a shirt or hat to advertise and attract attention to the vendor's booth. Since it costs several thousand dollars to erect a Ham radio tower, a few bucks spent to get such a sale could be a worthwhile investment, especially in the huge venue of potential buyers (20,000+) that Hamvention presents every year.

    No, I haven't purchased a tower for use here in Florida yet... but I am definitely looking for one that I can afford... perhaps a used one purchased from the estate of a recently deceased (Silent Key) Ham who had lived nearby. It seems a lot of people come to Florida to die in their favorite happy place, so turnover is high, but I haven't found anything yet.

    If @CABBAGE wants to give it a go with a PIC microcontroller, I am willing to help. I've got a bunch of PICs left over from the defunct Flashlight Project, so the only major expense is making a PCB. Well, there is also the time "expense" of climbing the learning curve, but that's what a hobby is all about, isn't it?

    Below is a rather poor cell-phone photo of the "tower flasher." The black blob on the left covers the microprocessor. The white circle on the right is the tactile dome switch. The LED (unlit in this photo) is centered at the top, with several SMD passive components around it. The two cell holders, covered with a paper sticker warning not to place them against skin, are located at the bottom. The series battery voltage, 2.8 V, is a bit on the low side to power most PICs, so a careful selection of design components is a must... maybe use additional cells or one or two lithium ion cells instead of zinc-air chemistry. You could add a boost converter to run the PIC from just one zinc-air cell or one lithium ion 3 V cell. There are lots of design options available, but I would start with learning how to use the PIC first and build from there. There are a lot of people in this forum who can help you.
    IMG_6801[1].jpg
     
  7. Audioguru

    Audioguru

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    Sep 24, 2016
    The warranty for my hearing aids ran out about 1 year ago so I recently bought a pack of zinc-air cells from Costco. They last 10 days (turned off each night) so the cost is less than $9.00Can for each one per year. They do not have LEDs.

    Hevans, I am sorry to hear that your brother passed away. I am 1 year younger than you (I am 73), I feel like I am only 53 and I have many things to accomplish in the next 20 or 30 years.
     
  8. hevans1944

    hevans1944 Hop - AC8NS

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    Jun 21, 2012
    I would like to think that I will be around for the next 20 or 30 years, but realistically that probably won't happen. There are too many co-morbidity factors to go along with my failing heart to survive all of them. In the mean time, I will just live one day at a time and try to be grateful for the life I do have. Trying to help people here may also help me to maintain my own cognitive abilities, so it isn't entirely altruistic. Plus, this is a fun and friendly place to hang out.

    Like you, I don't "feel" my age, at least not yet. In appearance, I could probably pass for sixty-something. But I do get shortness of breath when I bend over to tie my shoe laces or perform physical exertion. This isn't bad yet because I was able to dig post holes, mix bags of quick-setting concrete in a wheelbarrow with water and a hoe to set the posts, and build a wooden board-on-board privacy fence around my back yard earlier this year... about 150 lineal feet with two gates and mostly ten feet tall. A neighbor and my son-in-law helped.

    I do need oxygen to prevent feeling like I am suffocating when I try to sleep. And there is a chronic pain in my left shoulder that my primary care physician (PCP) has so far ignored, except to order some x-rays. Still waiting for him to tell me the results of that.

    I suffer diabetic neuropathy in both feet and probably poor blood circulation in my legs because the four stents implanted in arteries of my abdomen and in both legs may now be clogged. My PCP has ordered a lower abdominal CT scan with contrast, but because of my failing heart function, wife has suggested that I not do this test. The only possible diagnostic result would be a recommendation of another angioplasty to restore circulation to my legs, which is performed while I am conscious, but sedated, using fluoroscopic x-rays with contrast to guide the catheters. It is the contrast media she is worried about, but I have had both fluoroscopic as well as CT x-rays with contrast many times before without side effects. A second opinion (or more) from my interventional cardiologist may be in order. Meanwhile, we have cancelled the CT scan for now.

    Has anyone besides me noticed that @CABBAGE doesn't engage in a conversation here? He posts one question and is not heard from again until he posts another question. If this continues I will have to place him on the "ignore" list. Drive-by posters add almost nothing to Electronics Point. And it looks like I've hijacked another thread again... sorry 'bout that!
     
  9. Audioguru

    Audioguru

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    Sep 24, 2016
    Hevans, I am sorry to her about your medical problems.
    I also thought my end was near during my heart attack 10 years ago and a septic shock blood poisoning last year but the doctors fixed me quickly and I bounced back. The doctors also gave me improved vision (cataracts surgery with synthetic lenses in my eyes) and improved hearing (digital hearing aids).
     
  10. hevans1944

    hevans1944 Hop - AC8NS

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    I just now Googled "septic shock blood poisoning" and discovered there is a sixty percent death rate, probably because of a late diagnosis. You are indeed fortunate to have doctors who recognized your condition and treated it in time. My "medical problems" seem picayune compared to the conditions that you, and other people I have met since moving here, have survived. I am definitely grateful to still be alive and ambulatory, but I am not too sure how much bouncing I have left... recovery from the bypass surgery was slow and difficult. I try to moderately exercise, in an attempt to allow my heart to repair itself, but that may not work anymore. Every cell in the body has a strand of DNA, called a telomere, that controls how that cell reproduces and repairs itself. Problem is, each generation of cells shortens the telomere, and when it becomes too short to function the cell dies. That's my layman's view of it. I am sure the devil is in the details, and a good biology text would bring further enlightenment.

    For some reason, I have never really felt that death was impending, all the way back to 2000 when I had my first heart attack, without the usual symptoms of chest pain. Nor in 2011 when I collapsed on my bathroom floor in Dayton with congestive heart failure. My wife did notice some sort of symptoms prior to my original 2000 attack. She has had extensive Red Cross training, and was using that training to care for elderly, terminally ill, patients in their homes when I first met her. So, she stayed in the parking lot after dropping me off at work, waiting for me to call her if "I felt like crawling on the floor" which, sure enough, I did a few minutes after telling her I "felt fine." The trip to Dayton Heart Hospital was uneventful, but I had a hard time convincing the triage nurse that I had experienced a heart attack... until after they drew some of my blood and saw tell-tale chemical markers of a heart attack. That's also when I was first diagnosed with Type 2 diabetes, a contributing factor for heart disease.

    I have never had the chest pain that most people associate with a heart attack. I did marvel that I was still alive after recovering from one of my defibrillator shocks in the early months of 2017, but have experienced none of the "near death" adventures so widely reported by the media. No bright white lights at the end of a tunnel. No out-of-body, floating above everything, visions that I recall. Maybe I lack sufficient imagination to experience the "good stuff" before actually dying.

    I was diagnosed with a cataract in my left eye late in the previous century. My medical insurance kindly coughed up enough money to have replacement lenses implanted in both eyes. Best surgery I have ever had! Prior to that I suffered from severe myopia (nearsightedness), but now I can see clearly without glasses. I recommend this for anyone who must wear corrective lenses, whether they have cataracts or not. As you know, the procedure is performed with a local anesthetic on an out-patient basis, usually in the doctor's office, although mine was performed in a hospital where he practiced medicine.

    My hearing has been slowly deteriorating for decades now. Some of the loss could be attributed to listening with headphones to music played waaay too loud for many years, but I think it is just a natural consequence of aging for me. Periodically cleaning out the ear wax helps restore "normal" hearing for me, but my Florida Blue Cross Blue Shield PPO supplemental Medicare plan doesn't cover hearing aids, AFAIK. I should look into that again.

    When I applied for VA medical benefits several years ago, The Veterans Administration (VA) said that I was too far down on their priority list of patients with less income and more severe problems than I have, so they would not accept me as a new patient without a service-connected disability (which I don't have). Not that I want or need their services, nor would I voluntarily accept treatment by the VA for anything (they have a reputation of providing sub-standard medical care), but having a VA photo-ID medical card would instantly "qualify" me for a veteran's discount at many commercial establishments. Otherwise, I have to carry around a copy of my DD-214 discharge papers to prove that I served honorably in the U.S. armed forces.

    You mentioned you were prescribed digital hearing aids. I assume this means their audio response spectrum can be adjusted remotely, perhaps using near-field communications like my implanted heart pacemaker/defibrilllator does. If that is so, it would seem legitimate to offer such aids to do-it-yourselfers for self-tuning. Of course, the doctors won't let me "adjust" my implanted pacemaker/defibrillator device, and they will barely admit that I can turn it off with a permanent magnet. I wonder if the hearing aid racket has similar strong protections...
     
  11. Audioguru

    Audioguru

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    Sep 24, 2016
    All my life I dreamed about floating above everything (flying) not from looming death but instead from feeling freedom to do what I want whenever I want.
    My heart attack and septic shock were very sudden and I am lucky they occurred at home and my wife drove me to the hospital 5 minutes away.

    Can you activate your defibrillator yourself and does it feel like you were hit by a bus?

    My doctors, surgeries and most medications are paid for by my Canadian government health care. A grant is given to help pay for hearing aids and cataracts surgery. I paid extra to correct astigmatism.
    Today I went for a free checkup on the 4th anniversary of my hearing aids and got a hearing test and the audiologist peaked up the highest frequencies and discussed the latest models and tried to sell me them. My hearing aids have a Bluetooth range of only 2 feet so a receiver with booster is worn close for streaming and programming. The Bluetooth range on the latest hearing aids is about 30 feet. The audiologist can tweak the programming on the latest ones over the internet, but I like going their office.
     
  12. hevans1944

    hevans1944 Hop - AC8NS

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    Jun 21, 2012
    I used to have dreams of flying (without using an airplane!), but they have become rare lately. I was referring to so-called "out-of-body" experiences, which AFAIK I have never had, that occur typically while unconscious on an operating table. I can't imagine how that can even occur, given that the subject is under general anesthesia when their out-of-body experience occurs. Of course it is easy to make up a story afterward, and perhaps those telling the story even believe it. Doesn't matter. Belief systems only require faith, not facts.

    My defibrillator works in conjunction with my pacemaker to monitor and respond to atrial fibrillation. When it detects that an a-fib event is in progress, it charges up a high-voltage capacitor with sufficient energy to stop my heart. I suppose I could hear this happening if I paid more attention because it supposedly emits a high-pitched sound like a photo-flash unit charging up. When a sufficient voltage is reached, it discharges the capacitor and stops my heart, which also stops the atrial fibrillation. So far, my heart has re-started itself without further intervention and beats normally until the next a-fib event occurs. This only happened a few times in January, February, and March 2017 before my wife drove me to the hospital.

    As a hands-on electrical engineer, I have experienced electrical shocks on many occasions, although none deliberately. My most severe shock occurred when my forearm managed to bridge the terminals of a 300 V dry-cell battery. We used two of these, housed in a polycarbonate (Lexan) box, to positively bias the target stage of our particle accelerator, causing secondary electrons released when high-energy ions struck the target to return back to the surface from which they were emitted, instead of being counted as part of the incoming ion current. That accident led to a very serious set of burns on my forearm that took weeks to heal.

    My most recent shock occurred a few years before I retired. I somehow managed to get in contact with the output of a 40 kV, 30 mA power supply, used to accelerate positive ions through an Einzel focusing lens into the entrance aperture of an electromagnetic mass analyzer. The mass analyzer selected the ion species that was accelerated to high energies. In most installations, this sort of thing was protected by cages and interlock switches to prevent electrical shock, but our machine did not employ any such protection. Getting zapped with 40 kV is unpleasant but the experience was brief. I did not experience any interruption of my heart beat as near as I can recall.

    Getting shocked with the defibrillator is a similar experience. There is a strong, almost reflex-like reaction, and then it is over almost as soon as it has started. It does not feel like I was hit by a bus or kicked by a mule. And, no, I have no control over it, except to disable it. There have been no further a-fib events since my double cabg procedure. However, I can disable the implanted device with a strong permanent magnet. No doctor has told us when or if that might be a desirable thing to do. I have a DNR (do not resuscitate) order on hand that my wife can use to prevent doctors from artificially prolonging my life if there is no hope for recovery. I do not want to risk open-heart surgery, even to save my life, should that become a viable option in the opinion of some doctor.
     
  13. bigkim100

    bigkim100

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    Apr 17, 2013
    Some of the ICs that are used in Solar Garden Lights have an option to be used as a LED flasher as well. Either disconnecting, or connecting a pin on the IC would enable either flashing, or steady-on.
    I purchased a Fake LED flasher that is meant to mimic a Car alarm warning system, that flashed all nite long, using a small coin-sized rechargeable battery, and a small Solar Cell. This actually flashed for 3 years, and was only taken out of use because the plastic case had warped, and cracked in the heat of the sun.
    https://www.ebay.ca/itm/Simulation-...915077?hash=item1a7ec3dd45:g:5BUAAOSwo6lWOgbg
     
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