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  1. 3 points
    repairman2be

    0-30V 0-3A Latest Data

    Hi all, Finally after some months have gone by, my build of the Power Supply is done. I have used liquibyte schematic Rev. 8 and had made the cirquit board according to the Gerber.zip file he posted here: 0-30V Stabilized Power Supply Page 88 posted October 6, 2014 "http://electronics-lab.com/community/index.php?/topic/29563-0-30v-stabilized-power-supply/&page=88" I left out D10 and R15 as per his description. I have plenty of boards leftover if someone has a need for it. There was only one mistake liquibyte made which have outlined in one of the pictures uploaded here. I was fortunate enough to get a big case with a Toroidal transformer from the scrapyard. Also many parts are recycled from various sources. Regards, William
  2. 2 points
    So Finally which version of schematic is correct / flawless to build the PSU ?
  3. 2 points
    Illegal content (ebook/magazines/software) will be deleted without any notice. Thanks
  4. 2 points
    Calm down people. It is not Mixos's fault, if it is against the law he has to remove the content. This site is very good for asking electronic related questions, I have yet to find a better one.
  5. 1 point
    Introduction ---------------- Hi Friends, I am back again with another Arduino based home automation project. This time I am trying to make my partner's life easy by installing a collision avoidance system in the garage to help her park the car safely without hitting the garage wall. So, in this video, I am going to use an ultrasonic sensor to calculate the car's distance from the garage wall and display it using green, yellow and red LEDs. The color of LEDs indicates whether to keep moving, slow down, stop or go back. The total cost of the project is around $20 - $25. Step 1: Logic The project has 3 phases Phase 1: Waiting for the car In this phase the device keeps looking for a moving object within the sensors proximity. If an object enters the proximity then one of the three LEDs turns on based on how far the moving object is. If the object is way too close, then a noise is made to make the moving object aware of the distance. Phase 2: No car in the garage If there is no object in the proximity then turn off all the LEDs. Phase 3: The car has stopped moving (Parked in the right spot) If the object has stopped moving and is still in the proximity wait for 20 CPU cycles and then turn off the LEDs. Step 2: Hardware Requirement For this very simple project we need: - A Perfboard - An Arduino nano/uno (whatever is handy) - A Red, Green and a Yellow LED (Light Emitting Diode) - 3 x 220ohm resistor for the LEDs - One HC-SRO4 Ultrasonic Sensor - A Buzzer shield or A buzzer and a 100 ohm resistor - A 220v AC to 5v DC Buck step-down module - One Female Pin Header Strip - An Ethernet cable - Some connecting cables - A USB cable to upload the code to the Arduino - and general soldering equipments Step 3: Assembly Let start by connecting the LEDs to the board. Connect the Red LED to pin D2, Yellow LED to D3 and the Green LED to D4 of the Arduino by putting in a 220ohm resistor between the Arduino board and the LEDs. Now lets connect the Buzzer to analogue pin A0. Next, connect the Trig pin of the Ultrasonic Sensor to D5 and the Echo pin to D6 of the Arduino. Once all the modules are connected to the Arduino board, its time for us to connect all the positive and negative pins together. Connect all the positive pins of the modules to the +5v supplied by the Buck Step-Down Module and the negative pins to the -ve terminal of the Module. That's it, we can now upload our sketch to the board. In this assembly I am using 3 LEDs to display the distance, however you can replace the 3 LEDs with a RGB LED, or you can also use an array of LEDs like an audio level indicator to display the movement of the car. Step 4: My Setup OK now lets see what I have made. I have installed the Arduino, buzzer, the ultrasonic sensor and the three 220 ohms resistors on one Perfboard. The 3 LEDs and the power module is installed on a second Perfboard. I will be covering the LEDs with a translucent cover to give it a nice look. The 220v power supply will be connected to the screw terminal block. The base unit will then be connected to the LEDs and the power supply with an Ethernet cable. Step 5: The Code int trigPin = PD5; // Sensor Trip pin connected to Arduino pin D5 int echoPin = PD6; // Sensor Echo pin connected to Arduino pin D6 int redLED = PD2; // Red LED connected to pin D2 int yellowLED = PD3; // Yellow LED connected to pin D3 int greenLED = PD4; // Green LED connected to pin D4 int buzzer = A0; // Buzzer connected to Analogue pin A0 long TempDistance = 0; // A variable to store the temporary distance int counter = 0; // Counter value to check if the object has stopped moving void setup() { Serial.begin(9600); pinMode(trigPin, OUTPUT); pinMode(echoPin, INPUT); pinMode(redLED, OUTPUT); pinMode(greenLED, OUTPUT); pinMode(yellowLED, OUTPUT); pinMode(buzzer, OUTPUT); } void loop() { long duration, Distance; digitalWrite(trigPin, LOW); delayMicroseconds(2); digitalWrite(trigPin, HIGH); delayMicroseconds(10); digitalWrite(trigPin, LOW); duration = pulseIn(echoPin, HIGH); Distance = (duration/2) / 74; // Distance in Inches if(counter < 20){ // Do the rest if the car is still moving if (Distance > 200) { // Nothing in the garrage turnThemAllOff(); } if ((Distance > 55) && (Distance <= 200)) { // Turn on Green LED digitalWrite(greenLED, HIGH); digitalWrite(yellowLED, LOW); digitalWrite(redLED, LOW); noTone(buzzer); } if ((Distance > 15) && (Distance <= 55)) { // Turn on Yellow LED digitalWrite(yellowLED, HIGH); digitalWrite(redLED, LOW); digitalWrite(greenLED,LOW); noTone(buzzer); } if (Distance <= 15) { // Turn on Red LED digitalWrite(redLED, HIGH); digitalWrite(greenLED,LOW); digitalWrite(yellowLED, LOW); noTone(buzzer); } if (Distance < 8) { // Item is way to close - start the buzzer tone(buzzer, 500); } } if ((Distance == TempDistance) || ((Distance+1) == TempDistance) || ((Distance-1) == TempDistance)){ if(counter >= 20){ // Turn off the lights if the object hasn't moved for 20 cycles (no change in distance) Serial.println("No movement detected, turning off the lights"); turnThemAllOff(); } else { counter++; } } else { counter = 0; // Reset counter if there is a movement } TempDistance = Distance; Serial.print(Distance); Serial.println(" inches"); Serial.print("Counter : "); Serial.println(counter); delay(500); } // Function to turn the LEDs off void turnThemAllOff(){ digitalWrite(redLED, LOW); digitalWrite(greenLED,LOW); digitalWrite(yellowLED, LOW); noTone(buzzer); } Start the code by defining the constants and the global variables that will be used throughout the code. Then define the pin modes in the setup section of the code. Then create a function to turn off all the LEDs and the buzzer. Now, calculate the "Distance" in inches by reading the values received from the Ultrasonic Sensor. Then by checking the value of the "Distance" we will turn on and off the LEDs based on how far the object is. If the distance is greater than 200 then turn off all the LEDs and the buzzer as the object is out of range. Else if it is between 55 and 200 then turn on the green LED. If the object is between 15 and 55 then turn on the yellow LED, and if the object goes closer than 15 inches then turn on the red LED until it reaches 8 inches. When the distance becomes less than 8 start the buzzer along with the red LED. Next bit of the code is to set the value of the counter based on the cars movement which then decides when to turn off the LEDs. It compares the value of "Distance" with the "TempDistance" and if the values are same (object hasn't moved) then increments the counter. If the object moves any-time during this process the counter is reset to 0. Finally the "TempDistance" is set to the value of "Distance". Just before comparing the Distances we also need to check if the counter value has exceed 20. I am doing this to stop the below code from executing if the car is in a steady position. Lastly we just need to add a small delay to our sketch to pause the code for a while. Step 6: Quick Demo So this is how I have installed the unit in my garage. As I walk close to the sensor the light changes from green to yellow to red and ultimately the buzzer goes on when I am too close to the sensor. In my case I have installed the buzzer next to the Arduino however I will recommend you to install the buzzer along with the LEDs. If you want you can also flash the red LED when the buzzer goes on. So now, my partner can park the car easily without making any assumptions. Doesn't matter how many times she fail her driving test she is not going to break my wall (even when she is drunk). Not that I am asking her to drive when she is drunk (just kidding). Thanks again for watching this video! I hope it helps you. If you want to support me, you can subscribe to my channel and watch my other videos. Thanks, ca again in my next video.
  6. 1 point
    crazybuoy

    High volt power supply

    solved, thanks
  7. 1 point
    Tintin

    0-30 Vdc Stabilized Power Supply

    Hi, as promised I made an English translation of my working. Maybe there is few mistakes and I am sorry for that ! Good reading. ExplicationEN.pdf
  8. 1 point
    Hi Everyone, In this tutorial I am going to show you how to charge a Lithium 18650 Cell using TP4056 chip utilizing the solar energy or simply the SUN. Wouldn’t it be really cool if you can charge your mobile phones battery using the sun instead of a USB charger. You can also use this project as a DIY portable power bank. The total cost of this project excluding the battery is just under $5. The battery will addup another $4 to $5 bucks. So the total cost of the project is some what around $10. All components are available on my website for sale for really good price, the link is in the description below. Step 1: Hardware Requirement For this project we need: - A 5v Solar Cell (make sure it is 5v and not anything less than that) - A general purpose circuit board - A 1N4007 High Voltage, High Current Rated Diode (for reverse voltage protection). This diode is rated at forward current of 1A with peak reverse voltage rating of 1000V. - Copper Wire - 2x PCB Screw Terminal Blocks - A 18650 Battery Holder - A 3.7V 18650 Battery - A TP4056 battery protection board (with or without the protection IC) - A 5 V power booster - Some connecting cables - and general soldering equipments Step 2: How the TP4056 Work Looking at this board we can see that it has the TP4056 chip along with few other components of our interest. There are two LEDs on board one red and one blue. The red one comes on when it is charging and the blue one comes on when the charging is done. Then there is this mini USB connector to charge the battery from an external USB charger. There are also these two points where you can solder your own charging unit. These points are marked as IN- and IN+ We will be utilizing these two point to power this board. The battery will be connected to these two point marked as BAT+ and BAT- (pretty mush self explanatory) The board requires an input voltage of 4.5 to 5.5v to charge the battery There are two versions of this board available in the market. One with battery discharge protection module and one without it. Both boards offer 1A charging current and then cut off when finished. Furthermore, the one with protection switches the load off when the battery voltage drops below 2.4V to protect the cell from running at too low (such as on a cloudy day) - and also protects against over-voltage and reverse polarity connection (it will usually destroy itself instead of the battery) however please check you have it connected correctly the first time. Step 3: Copper Legs These boards gets really hot so I will be soldering them a bit above the circuit board. To achieve this I am going to use a hard copper wire to make legs of the circuit board. I will then be sliding the unit on the legs and will solder them all together. I will put 4 copper wires to make 4 legs of this circuit board. You can also use - Male Breakable Pin Headers instead of the copper wire to achieve this. Step 4: Assembly The assembly is very simple. The solar cell is connected to the TP4056 battery charging board's IN+ and IN- respectively. A diode is inserted at the positive end for the reverse voltage protection. Then the BAT+ and BAT- of the board is connected to the +ve and -ve ends of the battery. (That all we need for charging the battery). Now to power an Arduino board we need to boost up the output to 5v. So, we are adding a 5v voltage booster to this circuit. Connect the -ve end of the battery to the IN- of the booster and +ve to IN+ by adding a switch in between. OK, now lets have a look at what I have made. - I have connected the booster board straight to the charger however I will recommend putting a SPDT switch there. So when the device is charging the battery its only charging and not getting used Solar cells are connected to the input of the lithium battery charger (TP4056), whose output is connected to the 18560 lithium battery. A 5V step-up voltage booster is also connected to the battery and is used to convert from 3.7V dc to 5V dc. Charging voltage is typically around 4.2V. Voltage booster's input ranges from 0.9 to 5.0V. So it will see around 3.7V at it's input when the battery is discharging, and 4.2V when it's recharging. The output of the booster to the rest of the circuit will keep it's 5V value. Step 5: Testing This project will be very helpful to power a remote data logger. As we know, the power supply is always a problem for a remote logger and most of the times there is no power outlet available. A situation like that forces you to use some batteries to power your circuit. But eventually, the battery will die. Question is do you want to go there and charge the battery? Our inexpensive solar charger project will be an excellent solution for a situation like this to power an Arduino board. This project can also solve the efficiency issue of Arduino when in sleep. Sleep saves battery, however, the sensors and power regulators (7805) will still consume battery in idle mode draining the battery. By charging the battery as we use it, we can solve our problem. Thanks again for watching this video! I hope it helps you. If you want to support me, you can subscribe to my channel and watch my other videos. Thanks, ca again in my next video. TP4056.pdf
  9. 1 point
    Impressive. It is not easy to charge the 150ah battery with solar panel directly. For proper charging using solar panel you just need to use a solar charge controller. You must also place the batteries in parallel connection for fast charge. Using solar charge controller avoid reverse current flow from Battery to a solar panel and unharmed pannels from burning. For proper charging your solar panel must create power more than 150w 150w is the threshold point for your charging. More the power added ……charging rate improve.
  10. 1 point
    audioguru

    0-30 Vdc Stabilized Power Supply

    I use copper wire, not rice wire. They put rice in everything they make, especially batteries.
  11. 1 point
    audioguru

    acid_circuit

    Why are you using an old fashioned vented lead-acid battery? Most circuits today are powered by rechargeable Ni-MH or Lithium batteries that have no acid.
  12. 1 point
    Thanks for sharing this project. I just edited it a bit, so code would look better.
  13. 1 point
    Thanks for the resources!!! I am currently working on the project "Electronic circuits of information collection and processing systems". The topic is very interesting, since I need to investigate the development of the linearizer of the first sensor with smooth and piecewise-linear approximation. It is also necessary to determine the value of the DC component extraction device from the signal of the second sensor. In addition to your recommended resources, I also used the writingcheap.com service, which helped me with the theoretical part of my work of developing an analog-to-digital converter. Using the information of this site http://www.analog.com/en/products/analog-to-digital-converters.html I was able to summarize the results of my research. You have an extremely helpful channel for students on YouTube. You have an extremely helpful channel for students on YouTube.
  14. 1 point
    audioguru

    0-30 Vdc Stabilized Power Supply

    Since it was years ago I do not remember which page of which thread has version 6 or 7. I have the schematic and parts list of version 6 here:
  15. 1 point
    Fliptron

    Help Under standing Schematic PSU

    Hi Islam, I'm a new user here (just signed up to answer your question), so I hope this helps. There seems to be several things that need to be understood about the overall topology of this PSU to get to answering your questions The power supply has two main parts: 1) The control section with the GHI outputs from the transformer, generates +12, -6, and -15. The ground of the control section (center point, more or less) is connected to the Positive side of the output. See ground below C4, and on the far right of the page (has the number 15 near by). (I think these numbers scattered through the schematic are test point numbers). So all of the control circuitry (anything using +12, -6 and -15) Is referenced to this ground. What is a little surprising, is that means that as the power supply output goes up/down, the control ground is doing the same. Also on this signal, is one end of the each of the six Load-Balance/Current-Sense resistors (6 x 0.36 Ohms). 2) The second part is the power section, which includes the lower half of the transformer (ABCDEF), the relays that select between the 4 voltages you listed (15-20-30-50), the bridge rectifier D7..10. The Negative side of the bridge is directly connected to the negative side of the output. (the line at the bottom of the page with label 14.) The Positive side of this bridge rectifier goes to the 6 collectors of the 2N3055s, then the 6 resistors mentioned above, then to the Positive side of the output, which as described above is also the ground of the control electronics. Since the maximum current is 3 Amps, and it will be shared evenly between the 6 resistors (with very minor differences depending on the exact characteristics of the six 2N3055s), the maximum current for each resistor is 0.5 Amp. So the max voltage across these resistors is 0.18 Volts , which gives about 90 mW , so these resistors are grossly over-sized at 5W, and will run cold (unless they are mounted on the heatsink). This also means the voltage on the 6 emitters is 0.00 to 0.18, which is averaged by the six 100 Ohm resistors and then sensed by U2 which implements the current limit circuit. U3 implements voltage control, follow pin 2 to the right which goes to the ground symbol, which we have established is power supply's positive output, and pin 3 which is connected to a voltage divider (including the front panel control) which connects to the negative side of the power supply, marked with the label 14. So now to get to your question. Regardless of what the output voltage is, the six emitters are no more than 0.18 volts above the ground of the control circuits, which tracks the positive output of the supply. The bases of these transistors will be 0.6 to maybe 0.75 volts above that. So the base voltage is always in range of the control circuit driving it. For the same reason, the 2.5V reference is an offset from the control section ground, and the power section's positive output. Yes, the six resistors also carry the base current, but this is minimal, compared to the collector current, due to the gain of the transistors. At DC, 25 deg C, and collector current of 0.5 Amps, the gain is over 100. I just did a Science (see picture below) to make sure I wasn't lying: With 15 volts on the collector, I got the following results: Vbe Ib Ic Volts mA mA 0.5 .05 3 0.56 .15 22 0.6 .36 82 0.61 .5 122 0.63 .7 190 0.65 1.0 280 0.67 1.26 370 0.7 2.2 600 (Note, Vbe is using the voltmeter in the PSU, which is not very accurate, and the transistor heated up on the last few measurements, and needed to be cooled) Anyway, the measurements I made show a gain on my test 2N3055 of about 300 when the collector current is around 0.5 amps which is the high end of what is expected in this power supply, and would contribute about 0.3% of the emitter current. Thinking a bit further, it doesn't really matter since it is sensed along with the collector current, and it all goes out through the positive output of the supply. Cheers
  16. 1 point
    I am a regular PCB designer. Check my designs specimens. If you have such inqyiry in future then e-mail me at abid369@gmail.com or call on +923214322695 Sample Designs.zip
  17. 1 point
    This is a question always been asked so I try to make this list to cover as many pcb manufacturers as I can. This is a listing of websites making PCBs and also may including PCBAs. I will try to update the infomation now and then. http://www.pcbway.com/ -$5!!! http://www.pcbgeek.com/ http://www.sfcircuits.com http://expresspcb.com/ http://www.apcircuits.com/ http://www.10pcb.com/ http://www.goldphoenixpcb.com/ http://batchpcb.com/index.php/Products http://www.pad2pad.com/index.html http://www.pcbcart.com./ http://www.4pcb.com/ http://www.pcbfinpo.com/ http://www.sunstone.com/ http://www.pmsnewzealand.com/ http://www.ezpcb.com/ezpcbweb3/index.php http://dorkbotpdx.org/wiki/pcb_order http://pcbconnect.com/index.html http://www.screamingcircuits.com/Order/ http://www.pcborder.com/site_new/default.asp http://www.custompcb.com/ http://www.multi-circuit-boards.eu/?gclid=CK20v5fFga4CFYZN3godg1in6Q http://iteadstudio.com/store/index.php?cPath=19_20 https://www.itead.cc/open-pcb/pcb-prototyping.html http://www.seeedstudio.com/depot/fusion-pcb-service-p-835.html?cPath=185 http://imall.iteadstudio.com/open-pcb/pcb-prototyping.html?p=2&price=-100 - $0.2 !!! https://ecommerce.pcbfabexpress.com/ http://www.goldphoenixpcb.com/ http://oshpark.com https://www.protoexpress.com/ - SierraCircuits http://www.4pcbassembly.com/ http://www.mitchelectronics.co.uk/ http://www.customcircuitboards.com/ http://dirtypcbs.com/ http://www.elecrow.com/special-offer-for-2-layer-1010cm-max-green-pcb-510pcs-p-761.html http://pcbshopper.com/ http://smart-prototyping.com/PCB-Prototyping.html http://www.technotronix.us/ http://www.pcbunlimited.com/ http://store3.sure-electronics.com/ The list is not in any priority. I've never ordered board from any houses. I've just made board with the first two entries. This is a "work in progress". New board houses may be added, along with some comments.
  18. 1 point
    Dmitry

    MS.NET on ARM devices

    Some developers really need MS .NET Framework for some reason on their ARM devices (mainly on Raspberry Pi). So, basing on their requests, I have made a short tutorial on how to setup .NET on Raspberry Pi.
  19. 1 point
    HarryA

    Transformer Watts

    I enlarged the image off the Amazon.com but could not read it https://www.amazon.com/Black-Decker-LCS1620-Lithium-battery/dp/B01M6TQPY2/ref=sr_1_3/141-0275392-4037060?ie=UTF8&qid=1499813460&sr=8-3&keywords=Black+%26+Decker+LCS1620 ...but ebay.com has a readable image http://www.ebay.com/itm/Black-Decker-LCS1620-20v-20-Volt-Lithum-Ion-Battery-Charger-NEW-/272090041874?epid=1640405275&hash=item3f59d48e12:g:mf8AAOSwawpXr3eh 120v @60hz 300ma
  20. 1 point
    Soldertraining

    clipping circuit

    The clipping circuit does not have energy storage elements like capacitors but it includes both resistors and transistors. This circuit is normally used for the selection in the transmission purpose. The ability of diodes to allow the flow of current in only one direction. A diode is best tested by measuring the voltage drop across the diode when it is forward-biased. A forward-biased diode acts as a closed switch, permitting current to flow. No voltage exists at the diode but voltage may be present in the circuit due to charged capacitors.
  21. 1 point
    mars1

    0-30V Stabilized Power Supply

    hi any updates to this project
  22. 1 point
    Howie

    PCB manufacturing sites - work in progress

    WellPCB http://www.wellpcb.com WELLPCB is focusing on online prototypes orders, to meet the requirement of Low cost, Fast delivery, Easy order for customers around the world.
  23. 1 point
    youth

    PCB manufactureres

    I use WellPCB quite a bit. They aren't the cheapest, but the quality is superb, they may offer features and service you might need. http://www.wellpcb.com/ If it's only a single board or two I tend to make them myself.
  24. 1 point
    repairman2be

    0-30 Vdc Stabilized Power Supply

    @Jeremy You may have 2 PCB's for AU$5 plus shipping in an envelope. Two boards weigh about 44grams. Email me if you would like some to: weigenmann@mannix4mail.com Cheere, William PS. Seems your Kit has a problem to start with. Before I found this Forum I ordered two Banggood Kits. It is still not assembled and probably never will be. Anyway, over at this page there is a lengthy description on how to improve the Banggood kit. "www.paulvdiyblogs.net/2015/05/tuning-030v-dc-with-03a-psu-diy-kit.html"
  25. 1 point
    tripped

    Solar Powered Water Pump

    I have some questions I was hoping someone would help me work through. I am building an outdoor fountain that I want powered by a solar cell. Can I run the solar cell wires directly into the BLDC motor and have it operate only when sun is shining? The brighter the sun the faster the motor turns. Or do I need more circuitry to make it work? If I do hook up a small 3.7 v 2000 mAh Li Ion battery, I need a charge controller? And what? Pump Voltage VDC - 6.0 Nominal Current Draw: 0.27 Amps Power Usage: 7.0 Watts Solar cell Output Voltage: 0.5 volts (Vmax) Output Current: 3.5 Amps (Imax) Average Power: 1.75 Watts Is there any way to turn the motor on for 1 minute every hour on the hour? Miniature controller or driver of some sort? System as compact and concealable as possible. Any help out there For this one? Oh one more thing, is there a micro charge controller out there that would protect the battery when it was full by dumping the load into some LED’s or something of that nature?
  26. 1 point
  27. 1 point
    In PCBWay, the boards are good quality and pricing is great while OSH Park is an aggregator. They collect your board files and panelize them with others to get a good price. And in case of Smart-Prototyping, especially their PCBA services. Their service is very affordable.
  28. 1 point
    The ebay kit that is a copy of the original faulty Greek power supply on this site is also sold by Banggood and Amazon. Banggood is selling it at a clearance price since they probably had many complaints. They have modified it a little and are selling it again as a kit with a 28V/2A rating and an LCD meter for it. The very nice looking 30V/10A power supply is extremely cheap. Its ad has no detailed spec's. It does not even say if the voltage and current are regulated. If something looks to be too good then it probably is not true.
  29. 1 point
    You ask for a lot! Start with Ebay.com for transmitters and receivers: see: http://www.ebay.com/itm/Mini-88-108MHz-FM-Transmitter-Module-Wireless-Microphone-Dictagraph-Interceptor/141659602950?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D40832%26meid%3D5caec1e4bbe74e2fa065b6379434198a%26pid%3D100005%26rk%3D2%26rkt%3D6%26sd%3D111649741072
  30. 1 point
    stuee

    12v lamp Dimmer lamp ideas?

    I have a 12v transformer for interior lights and a few lights for it, but want to make it a dimmer light. the working amps are 250mA. I would like to know how to wire up these three ways, so i can try each one and see if its any good and use the best.... Touch lamp. touch the metal to turn on dimmest. press again for brighter and again for brighter and again for off. Manual pot adjuster. and digital potentimeter. press up to turn up and make brighter and down for darker / off, and a reset button to turn instant off. Any help and sche... will be helpfull. Thanks in advance
  31. 1 point
    monkfinger

    0-30V 0-3A Latest Data

    Hi all Ok, this is my end result. Built and tested and works quite well. I started with the version posted at the start of this thread. However I had a couple of problems with the current limiter. I didn't have much success with the current limiter clamping the input of U2 - sometimes it would not go right down to 0V, sometimes it would go just below. Just below was a big problem for me - U2 would start to oscillate, with bad consequences for anything connected to the output of the Q4... It would then drive the output high just when I wanted the current limit to become active I should add that I did not use TL2141 or MC34071s, this might be the root of my problem. I fixed this issue with a small change to circuit layout rather than going to expensive opamps. My mods (compared to the circuit posted on start of this thread): * current limit - I removed D9. To replace this, I added another BC548 - the base is driven by the current flowing through the current limit LED. The collector of this BC548 clamps the output of U2 (exactly like the existing BC548 driven by the negative rail). This arrangement means we don't care how close to its supply voltage the output of U3 can go. It avoids the possibility of driving the input of U2 out of spec. Clamping the output of U2 is much more like how the integrated voltage regulators work. It seems better to my mind, to keep U2 out of the loop when current limit is active. [Edit: note that U2 will need a small heatsink with this arrangement] * some rearrangement of the opamp power connections, for all three opamps... U1 & U3 are run via 15V zener diodes, to give a supply of approx 30V. That allows almost any cheap opamp to be used for U1 & U3 (741s or TL071 etc). U2 is connected to unregulated 44V and to the output side of the 0R47. * I used a MC33171 opamp for U2. It is high voltage, but much cheaper (they are £0.60 in UK) than TL2141 or MC34071 (both are £5 here). It is a low power IC by comparison. * 0-30V 4A transformer. * 2 x 6800uF smoothing caps.a big thanks to the contributors on this thread for their efforts, my project was greatly speeded up by borrowing a lot of their ideas Edit: * I also changed the 0R47 to 0R2, as the 0R47 generated too much heat at 3A for my liking. This also means R18 changes to 330K. These two values are not shown on the schematic here.
  32. 1 point
    Check this out! Awesome Project!
  33. 1 point
    vin_killah

    STK407-070B Datasheet

    Hi, where can I find datasheet of STK407-070B? I just want to make a home made amplifier. thanks :D
  34. 1 point
    eplanet

    2n2222 resistor value

    thanks hero999 is there any formula for this issue? my coil is 57ohm
  35. 1 point
    ptkindt

    Tesla with A811 tube

    I made a Tesla transformer with a A811 tube. I did not force anything, it can run for hours. The making of: http://www.youtube.com/watch?v=H7nivw7zxNM The result: http://www.youtube.com/watch?v=Mp721VgxWQI
  36. 1 point
    hotwaterwizard

    DATASHEET OF SE336 (SMD IC)

    TOYOTA Car indicator flasher part number TOYOTA:81980-50030.
  37. 1 point
    gogo2520

    Electronic suplus stores

    Hello RFamateur and welcome to the form. Here are a few. These have stuff some good lot outdated. http://www.goldmine-elec.com/default.htm http://unicornelectronics.com/prod.htm http://www.mpja.com/category/LEDs/LEDs.asp http://www.futurlec.com/index.shtml http://www.allelectronics.com/ http://www.danssmallpartsandkits.net/ http://www.alltronics.com/assortments.htm These are good suppliers http://www.mouser.com/index.cfm?handler=home http://www.futureelectronics.com/en/Pages/index.aspx http://www.web-tronics.com/ http://www.jameco.com/webapp/wcs/stores/servlet/StoreCatalogDisplay?storeId=10001&catalogId=10001&langId=-1 That should get you going. gogo
  38. 1 point
    Hero999

    Re: high voltage meter problem

    The meter will have an impedance of 10M so to divide by 10, all you need to do is connect a 90M high voltage resistor in series with it. This can be made using nine 10M resistors in series, each resistor needs to be rated to 1/10th of voltage being measured.
  39. 1 point
    audioguru

    Electronic Gun !!!!!!!!!

    Hi Shantanu, Electrolytic capacitors have a vent on top to slowly release gasses that build up when the capacitor is connected with backwards polarity then has a high current. With a very high current, the vent cannot release the gasses slowly so the capacitor explodes. A 9V battery cannot provide a very high current. Maybe a battery made with series-connected AA Ni-Cad or Ni-MH cells would provide enough current for a backwards electrolytic capacitor to explode. Bad-smelling "fluff" comes out.
  40. 1 point
    grsparks

    An excellent electronics manual

    After running across this at the public library in town, I just had to order my own copy: "Practical Electronics for Inventors" by Paul Scherz It covers just about everything from DC to Microcontrollers and is well illustrated.
  41. 1 point
    Here is the book in pdf for you all. You can press the free button and you have to wait about a minute then it gives you the links. Just pick one. http://rapidshare.com/files/3372603/Practical_Electronics_for_Inventors.pdf
  42. 1 point
    You are breaking the hearts of all the hobbysts who can not afford the cost of buying the books from amazon. most of us are ametures using the books for refrences or some other information. i dont think someone is making millions using these ebooks.
  43. 1 point
    What about links to "illegal contents" like, Can we use rapidshare or other sites to upload such illegal contents and then provide links through e-lab?? (As Elektor magazines thread hasn't been deleted)...... Books posted by Ante were really beneficial and one of the best features of e-lab.....Anyway, legal problems can't be ignored.......
  44. 1 point
    I am very sad too :-[ [move] :'( :-[ :-\ :'( :-[[/move] No doubt, ER has been the one of most attractive features of the site. All the thanks and respect goes to Mr. Ante for such a good contribution to this part of site. I now request MIXOS to leave the contents as it is not reasonable to throw away ones friends(books).
  45. 1 point
    Here is all I have Playstation2_Repairguide.pdf
  46. 1 point
    GPG

    12v lamp Dimmer lamp ideas?

    http://www.lsicsi.com/ Easier to get here. HWW its AC.
  47. 1 point
    ante

    Electronics Goldmine!!

    MP, Just click on
  48. 1 point
  49. 1 point
    juanpmoron

    0-30 Vdc Stabilized Power Supply

    R16 is 1K and is OK ???
  50. 1 point
    MP

    0-30 Vdc Stabilized Power Supply

    Think of the commas as periods or the periods as commas. These are used differently in different continents. It means the same. MP