Basic and brief video talking about LED lighting and demonstrations, including the basic use of fibre optic cable, basic LED light electronic circuits using 3V and 9V batteries, plus incorporating resistors into circuits where appropriate.
If you enjoyed this video, please like and share. :)
If you would like to receive notifications of the latest Dramamask Evolution videos, don't forget to hit the notification bell. :)
An idea for a computer speaker for modular office furniture. The sound quality for this prototype was not great, but it is convenient and clears the desk of other speakers. Please note that the 4 ohm speakers might lead to the amplifier getting quite warm. I'd recommend either a lower voltage or 8 ohm speakers.
PLEASE SUBSCRIBE to my channel to be kept up to date with my latest FPV / Aerial Video & Flying Videos, plus much more!... DONT FORGET to give this video a 'thumbs up', as this will help the video to come up on searches for other people like you and me who are into this type of stuff...
Thanks for watching, all comments are welcome & strongly encouraged (but please be nice) :)
A 2-Way transmission line speaker to be used with the Linkwitz-Riley active crossover and amplifier circuits shown in previous videos. For the design, I used results from an on-line transmission line speaker calculator and folded it a bit to fit in a shorter box and have the opening facing forward. I don't think the bass comes through in the video. It actually sounds pretty good.
A closer look at the active crossover circuit. This board is available at OSH Park as a shared project (search: Active Crossover). The intent is for a common interface board between a signal source and powered 2-way speakers. This is not a heavily engineered circuit. It is just what I used in a project and I wanted to share it. I apologize for the poor audio quality.
An overview and test of the Linkwitz-Riley crossover for the pair of speakers I'm working on. The actual crossover frequency appears to be just under 2400 Hz, or about 6% higher than the design frequency of 2250 Hz.
A look at a few different types of active crossover circuits for an upcoming speaker project. A first order RC filter with 6 dB/octave, a Sallen-Key second order filter with 12 dB/octave, a cascaded Sallen-Key and a Linkwitz-Riley fourth order filters with 24 dB/octave roll off are simulated using LTSpice.
A circuit for "remotely" controlling a pair of powered speakers. The control box allows one to turn on power and adjust the volume of each speaker from a centralized location instead of doing the same at each speaker. Power is controlled using a p-channel mosfet and one pin of an XLR3 cable.
This is an MP3 player made from components I got off eBay. A panel mount MP3 player sends the audio signal to a 2x10W amplifier based on a PAM8610 chip. The speakers are HiWave BMR12 full range drivers.
My son also wanted an MP3 player. I couldn't distinguish stereo sound on my daughter's MP3 player because the speakers were somewhat close together. So this time I made a mono speaker with an active crossover, a 4" woofer and 1" tweeter. This video is mainly for documentation; a few audio clips and an overview of the circuit and speaker components.
A small addition to an audio amplifier to reduce pop when turning on the power. I'm using a TPA3118D2 based amplifier that I bought on eBay. I ended up using a 10uF capacitor and an SB130 diode because that is what I had in my spare parts box
I decided to borrow most of the components from the bi-amped active crossover speakers and use a tweeter instead of a full range driver. The crossover itself is a board that was made for an MP3 player for my son. I got three from OSH Park, so one for the MP3 player and two for these speakers. Overall, I am quite happy with these, but the bass is a bit strong. It may be good to stuff the box and dampen things out.
I had a couple of Peerless 5-1/4" subwoofers and decided to make some two-way speakers. The subwoofers were paired with Tang Band 3" full range drivers that had a similar sensitivity rating. Each speaker is powered by a 20 watt stereo class D amplifier from Adafruit (10 watts per channel with a 12 volt supply and an 8 ohm load). The left channel is used for the full range driver and the right for the subwoofer. The crossover consists of LM833 audio op-amps in Sallen-Key high pass and low pass filter topologies. The filtered signals are then sent to the appropriate driver amplifiers. Note: in the crossover simulations I used 15k ohm resistors, but in the actual circuit I used 16.2k ohm resistors. I like how the speakers sound; although, they don't sound as good in the video. I don't have a microphone (yet) to measure their true performance. Volume can be set for each speaker using a potentiometer on class D amplifiers. But it would be good for the source to have its own master volume control. Some sample music is provided at the end to show how it sounds with different music styles.
I added a simple bass boost circuit to the shelf speakers I made earlier. It is based on an LM833 audio op-amp. The intent was to increase the gain on frequencies below 100 Hz where the output of the speaker rolls off in hopes of extending the range a bit.
A speaker designed around the Tang Band W3-881SJF 3" full range driver. I plan on playing classical music with these speakers in my office. So the emphasis was on small size without a ton of bass. I am very pleased with the way these speakers turned out.
This is a powered speaker that is intended to look a bit utilitarian. It is powered by a 9 volt wall wart and accepts an audio signal through a stereo 3.5mm jack. The stereo signal is converted to a mono signal through a resistor network before being fed into an audio opamp and finally a small power amplifier. There is both gain adjustment and volume adjustment. The speaker is a HiWave BMR12 full range square speaker. The stereo to mono is just two 4.7k resistors (one for each channel) feeding a 47k resistor. If you Google "line in stereo to mono circuit" the image will probably show up near the top.
A guitar amplifier with more of a flat format. This uses a small class D amplifier along with a Dayton Audio exciter to turn a 1/4 inch thick White Birch plywood panel into a speaker. I like this amplifier because it is light, folds up for easy storage and transport, does not have a paper cone that needs protection, and has a warm tone. On the down side, it is not as loud as a typical speaker of the same wattage I think this would be best used with an acoustic guitar.
A small 5 Watt amplifier based on an LM4950 chip amp. The speaker is a GF1004 from DigiKey, the op-amp is an LM833 and the MOSFET is a 2N7000. Some details of the box construction are given. Overall, I'm pleased with the way it turned out. There is a slight crackling noise which I haven't tracked down the cause of yet. It produces enough sound for a small room. The circuit board and parts list can be found at OSH Park.
Nicer to look at Hygienic & clean No unappealing extra tissues wasting in-between Cut down time till climax So quick it couldn't hurt Go on Switch off Repeat it Your dogma might work
Atrocity You couldn't see Too hideous for you but it's quite okay for me A mutilated infancy When will you grasp hypocrisy?
Atrocity Dismissed, condoned A matter of some humour Can't compare with sharpened stones Can't compare with dirty blades Can't compare with filthy men And the screaming's not the same And the bleeding's not as red 20 minutes ripped from life And local anesthetic fades And cortisol is wildly rising Outside forces own your pain Far inside a feeling that it just won't go away So you’re lucky that it's not at all the same
Atrocity You couldn't see Too hideous for you but it's quite okay for me A mutilated infancy When will you grasp hypocrisy?
Atrocity You will not see Too hideous for you but it's quite okay for me A mutilated infancy When will you drop your fallacy?
This is the completed line array speaker with 12 full range drivers. Each driver has a 1-Watt amplifier mounted on the back of the speaker. Details of the enclosure construction are presented. The electronics are described in a previous video. The input circuitry will be cleaned up a bit and mounted one the back as well after a bit of testing.
I'm working on a diy line array speaker. The plan is to have a dozen 1-1/2" diameter full range speakers spaced about 2-7/8" apart in a line. Each speaker will have its own 1-Watt amplifier. The inputs to the amplifiers will be driven by circuitry described in this video. Note: this is my first attempt at a line array speaker and I am not an electrical engineer. So take what is presented here with a grain of salt so to speak.
A circuit intended as an assignment for a class on EagleCAD. It is a one watt audio amplifier based on the STM TS4871 chip. It is powered by a USB cable, and the signal comes in through a 3.5mm jack. The speaker used to demonstrate the circuit is built around a Dayton Audio CE40P-8 speaker. This is a 1-1/2" speaker that is rated for 2 watts.
A circuit for protecting supercapacitors that are wired in series. This circuit is similar to those that can be purchased online except it uses a low power LM4041 for a voltage reference and a single NPN transistor. Shunt current is limited to about 300 mA, so it should only be used in low wattage application.
A buck converter circuit is used as an interface between a small solar panel and a super-capacitor. The input voltage from the solar panel is regulated to keep it operating near its maximum power point. The output voltage is controlled in the usual way to prevent the capacitor from overcharging. An LED driver uses the stored energy to provide light when the sun goes down. This project was inspired by Mad Electron Engineering's Infinity Sun Jar. I was trying to do something similar using "jelly bean" components.
This is a brief test of NVE Corps. AAH002-02E magnetic sensor. This is a high sensitivity, single axis version intended to sense the Earth's magnetic field (among other things). It has an operable range of 0.3 - 3.0 Oersted field strength (the Earth's field strength is around 0.5 Oe). In this test, a small screw driver is magnetized and brought near the sensor to see what sort of output it would provide after going through an amplifier with a gain of approx. 10. The output is sensitive to the orientation of the magnetic field; varying with the cosine of the angle between the sensor and the field. There are other versions of the technology that are more suited to angular measurement, but this one seemed the easiest to handle for initial testing.
My previous controller was based on an MC34063 which is rated at 1.5 Amps which is too low and the controller failed. This controller uses an LM2596 buck converter controller which is rated at 3 Amps which should be adequate for my small wind turbine. The previous controller also operated in a burst mode; that is the controller was turned on and off at a relatively low frequency and a duty cycle that was adjusted based on the average input current. The problem with this type of control is that the MC34063 was always running up to its peak current capabilities while it was on. I believe that sort of harsh treatment led to its failure. This controller limits the current to a low level on a cycle-by-cycle basis so the switch is not so heavily stressed. Other benefits to this circuit are input over-voltage/turbine over-speed protection that does not depend on the micro-controller, battery over-voltage protection, and a MOSFET switch on the output to the battery to prevent drainage when there is no wind.
I'm considering designing a VAWT controller around an LM2596, so I thought I could just use one of those inexpensive boards that cost about as much as the chip itself (quantity one). But it appears that they will not do an adequate job. First, it seems the LM2596 chips do not run at the advertised speed. Unless I am missing something, the boards I sampled were running at just over 50 kHz; much like an LM2576. The second problem is I'm not certain these boards will run in continuous conduction mode when charging a 12 volt battery with a relatively high voltage input. I'm thinking they would need a higher valued inductor. It might work fine with lower voltages, but a wind turbine would need the higher current at a higher input voltage. (11/8/14)
I bought an inexpensive LM2596 CC/CV buck converter in order to see how they were handling constant current control. This video is the result of the teardown. I believe this board is intended for battery charging applications. It can be found at eBay and other places for around two to three dollars; about than the price of the LM2596 chip itself in single quantities. My other objective was to see if this board would be suitable to be used as part of a VAWT controller.
The ATTiny10 is a small 6 pin micro-controller with an 8 bit processor, 1k programming memory, 8 bit ADC, and one timer for PWM outputs. Three pins are for power, ground, and RESET which leaves three useful pins (RESET can be used as a i/o pin but re-programming is more involved). However, three pins can do a lot; simple control, signal conditioning, basic timing, switching . . . This is a demonstration of programming an ATTiny10 using Atmel Studio to generate a hex file and an Arduino to upload the file into the ATTiny10; a method described at junkplusarduino.blogspot.com. (10/12/14)
This is a small bass amplifier I built to have something portable but still capable of hitting low notes. The speaker is a Tang Band 6-1/2" Woofer and the amp is based on a TPA3125D2 Class D amplifier chip.
A project to provide wind speed data to the internet. An Arduino is used to measure the wind speed. It communicates via USB cable with a Raspberry Pi to provide the current data on demand. The Raspberry Pi inserts the data into a web page. This may not be the most elegant solution, but for the moment it is what I could get working. The Raspberry Pi is running Apache to serve the web pages which are written in HTML and Php. Python is used to communicate with the Arduino. The web page can be seen at winddata.noip.me provided it is up and running. It is still a work in progress. My hope is to interface the Arduino with a current controller for the VAWT 035 wind turbine to provide data on its performance as well. Note: this video is from April of 2014. The web server is no longer in use.
A way to measure RPM by simulating an LM2907 is demonstrated using an Arduino and Adafruit 16x2 LCD display. This technique uses one digital pin and one timer. The timer generates an interrupt every 4 ms. The interrupt routine checks for a change on the input pin. If there is a change, a constant value is added to an accumulator or "bucket." In either case, pin change or not, the accumulator is multiplied by a value less than one. The value in the accumulator represents the RPM of the rotor generating the signals. The advantages of this technique include: regularly spaced interrupts, no division operations that could result in a divide by zero error, no timing problems with RPMs near zero, provides a cap on the maximum RPM, and no subtraction operation that could result in a negative value. It appears to be a robust way to measure RPM. It is best to use signals with approximately 50% duty cycle. Variations in the duty cycle might cause problems if used to measure frequencies near the theoretical maximum.
Documentation of a couple modifications made to the PCB board. The modifications include an improved circuit for turning on the 12 volt regulator and replacement of the frequency to voltage converter with a more conventional transistor circuit. All the diodes have been installed, modifications have been made to the software, and a test run was made with a VAWT PMA.
This video describes a work-around solution for a start-up issue I am having with the MOSFET driver. Under certain conditions, the driver will fail to turn on the MOSFET even though the TL494 is sending a signal to turn on. However, if that input signal is removed momentarily and then reapplied, the driver operates as intended. This work-around uses a 2N3904 npn transistor in parallel with the TL494 output transistors that is controlled by the ATTiny85 micro-controller to remove the input signal during start-up conditions.
This is a PCB version of the input current controller. It is a buck converter using Average Current Mode Control to control the current being drawn from the turbine (output current from the turbine / input current to the controller). The idea is to measure the RPM of the turbine using one leg of the PMA just before the rectifier and then program the controller to draw a current that is proportional to the square of the RPM. This is not Maximum Power Point Tracking, but it should load the wind turbine in a way that keeps it near its peak power production. This is an implementation of Lloyd Dixon's paper on Average Current Mode Control. The pulse width modulation is generated using a TL494 running at approx. 100 kHz. Calculations are made using an ATTiny85. The turbine speed is sensed using an LM2907 frequency to voltage converter. The n-channel MOSFET is driven using a high side driver, and the current is sensed using a 0.01 ohm series resistor and a high side current monitor with a gain of 20.
Some details regarding the input current controller circuit and design calculations. This is my interpretation of a paper entitled "Average Current Mode Control" by Lloyd Dixon. The intent is to be able to control the current drawn from a wind turbine in order to optimize its operation. If too much current is drawn, a VAWT will stall, and if too little is drawn, power will be wasted in aerodynamic drag.
A quick video of a circuit I'm using as an input to the prototype current control. It is simply an ATTiny85 that is reading a potentiometer, scaling the ADC reading and sending that value as a PWM signal out one of the pins. The PWM signal is then filtered by an RC circuit. This video looks at the characteristics of the analog output. The analogWrite function creates a PWM signal of 500Hz. The final filter uses a 4.7uF capacitor with a 13kOhm resistor. It has a corner frequency of about 2.6Hz and a ripple voltage of about 40mV. With a little bit of code, the PWM frequency could be upped to say 5kHz and the ripple would drop considerably.
I'm working on a circuit to control the current coming from a wind turbine to help it run at its optimum speed. One task for this controller is to measure input current. It could be done with a series resistor and a high side current monitor or a hall effect device, but I wanted to try it with a current transformer since I hadn't used one before and I wanted to see how it worked. This video shows the signal coming from a current transformer and some modifications to the basic circuit to get the desired waveform. Please note that according to the literature I read if your current is always positive as in this case the current must periodically go to zero to let the core "reset." (the term the author of the paper I referenced used) I added a diode that was not present in the literature because it seemed to be a good addition for circuit protection. (Note: I am not experienced in working with these transformers)
I'm working on a circuit to control the current being drawn from a VAWT to help the wind turbine run at a near optimal speed. This buck circuit uses a TL494 to implement an Average Current Mode Control scheme where the current to the switch (input current) is monitored and controlled. An ATTiny85 is used to generate a PWM signal to set the desired current. In the final design, the ATTiny85 (or similar ucontroller) would measure the wind turbine RPM and set the desired current that the turbine should be producing at that speed. If too little current is drawn, the turbine would lose energy to drag by spinning too fast. If too much current is drawn, the turbine would stall and produce little energy. This is different from my earlier controller in that the input current is being controlled directly as opposed to guessing what the input current is based on the output current setting and knowing the input and output voltages. (Note: this was one of my earlier prototypes (Nov 2013) but I'm posting this because I thought the TL494 circuit was interesting)
A quick demonstration of the prototype input current controller. This is a buck type SMPS which uses a TL494 controller. The purpose of the circuit is to control the current coming into the SMPS in order to regulate the power being taken from a vertical axis wind turbine. If too much power is extracted, the turbine will stall, and if too little power is taken, power will be lost to drag. This video just shows the controller going through its paces using a stepped reference input. I am quite happy with the results and will be making a PCB soon. An ATTiny85 is used to generate the stepped reference signal and to provide a PWM signal to a charge pump used to bootstrap the MOSFET driver. A video detailing the design of the TL494 compensation circuit is in the works.
A detailed look at an RPM sensor for a wind turbine using an LM2907 and one of the phases from the alternator. The output is a voltage that when sampled by a 10 bit A/D converter will yield 1 ADC count per RPM. The frequency response is low (about 1/2 second time constant), but the turbine RPM should not be changing too rapidly anyway. Calculations are shown at the end of the video.
A microcontroller based boost circuit. The hope was to pair it with a wind turbine and match the load to the turbine with the wind conditions. I later just decided to go with a buck configuration for efficiency.
The objective of this project is to develop an Autonomous self driving car rover using Arduino, Raspberry pi machine learning and deep learning resources in Firstly creating PID controllers to maintain Desired Target outputs Before trying to apply machine learning and deep learning Principles.
My homemade desoldering head and pump unit, made to fit my existing Antex 100 watt iron, here I made a huge saving over the retail paradigm, the soldering iron is made in the UK and has its own temp control. All the brass parts came from out of my brass bittzer box, the vacuum pump was new as was the glass filter tube.