mixos

Thanks ;) Check this out: How to Create Footprints in OrCAD Layout http://www.egr.msu.edu/eceshop/pdf/an_pcb_2t12.pdf

If you are looking for labels to organize your resistors and be able to find them easy and fast you can print out the following sheet and cut each piece of label to attach it to your boxes. It inlcudes all the common resistor values at 5% tolerance.

This topic has been also discussed here: http://www.electronics-lab.com/forum/index.php?board=13;action=display;threadid=58;start=msg153#msg153

Hello iraq_mosul To make fine soldering you need: 1. a very thin nose on your soldering iron that may be less than a millimetre at the end 2. a very steady arm 3. lot of passion 4. lot of exercise 5. and a fine piece of soldering That's all you need to make a succesfull fine soldering. Alternative to the fine nose you can take a piece of copper wire and turn it over the current nose of your soldering iron. Then you will solder with the end of this wire.

Hello Read this: Digital Stopwatch 0-99sec http://www.electronics-lab.com/projects/oscillators_timers/014/index.html and then read this: Digital Stopwatch 0-60sec http://www.electronics-lab.com/projects/oscillators_timers/015/index.html To understund the basic of a digital stopwatch. Then you will have to make it also reverse count with a little research. You can replace the timebase using the 555 timer. Hope this helps for beggining. Also i attach you exaclty the same schematic as "Digital Stopwatch 0-99sec" but in another design that will help you to understund it better.

:'( :'( Bad to hear it! I searched on the net and found nothing either. What means "OUS" here: "....who did find a similar type product from OUS" Now i am going to search: VPC at 800-447-1944 Metal Photo at 800-482-7758 I will post later the results. Also another way to label boxes is the Toner Transfer Method from Pulsar.gs You can find more info about this product on their site, but i think you can't label BLACK or dark color boxes.

I done the corrections for you maestrodamuz! Thanks

These are the contents of the zip file for fast view of another 7107 digital voltmeter (it's almost the same, but this one incudes the +/-5V power sources)

This is the FIXED SCHEMATIC (22-2-04):

First of all I attach here the FIXED SCHEMATIC (22-2-04): I attach also two sample power supplies for this voltmeter: Hope this one solves all previously mentioned inconsistencies. Also the schematic at the project's page is updated: http://www.electronics-lab.com/projects/test/014/ blacksheep : To measure the current flows a load you use a small resistor in series with the load and you measure the voltage drop on it. Then with ohm's law you calculate the current pass throught the resistor and throught your load. You can't easily measure the current right away. So you can use the same circuit to measure the voltage drop across a resistor. For more info on how to do this see the pdf file i indicated previously.

blacksheep: you can use this Voltemeter as ammeter also using the connections see below: You connect the ammeter in series with the load and voltmeter in parallel with load. To take a current measure there must be a load connected :D Also you can read this: http://www.electronics-lab.com/forum/attachments/Digital_Panel_Meter.pdf explaining different connections and R calculations. Or use this to measure current:

Why let your projects lying in a corner of your hard disk? Make them available to the world... ...and enter the chance to win an auto range digital multimeter Submit your project to [email protected] until 21/4/2004 with your name and contact e-mail address. Files are preferred to be in a zip format. Subject of the e-mail must be: "Contest Participation". All projects will be published under "Projects" section with your name and e-mail. >>more info here

Hello Gusk4x4 If you use the PCB, this voltmeter will work very nice. There are some errors at the schem and maestrodamuz has poster here the corrections along with some modifications to measure AC exept from DC voltages: http://www.electronics-lab.com/forum/index.php?board=4;action=display;threadid=353&start=0 Hope this clarify things

Check this project: The 8Way Relay Board http://www.electronics-lab.com/projects/pc/005/index.html If you develop a new software, share it with us!

Hi faris :D , Welcome to Electronics Lab Community!! What exactly will be the power source? Something like this: Dynamo Powered? http://www.campingsurvival.com/dynflaswitba.html Shake Flashlight http://k3www.com/shake-flashlight.html Faraday's Principle (the same principle with the above) http://www.thinkgeek.com/gadgets/lights/5a9f/ Also check this conversation here: http://www.electro-tech-online.com/viewtopic.php?t=5998&postdays=0&postorder=asc&start=0 Tell us if you find or build something else.

Yes right FireFly :D, that's what we are trying to do with this power supply right now, to make it reliably live up to its specs !! The transformer is good to be 4A or even 5A Staigen recommended a high value capacitor, something like 10000uF/50V if you can find one. Otherwise you can use some connected in parallel. The sure is that a higher value than 3300uF is needed. Rectifier bridge diodes 1N5402,3,4 are easilly overheated and for that reason a ready made bridge rectifier (at higher power rating, even 8A-10A) is proposed to be used off the board, attached to the box of the power supply for better cooling. We waiting Staigen to make his proposals, because he is a real PSU expert!! Where are you staigen :D ?

Billy you can freelly start a new topic: Home made etching tanks. We have to discuss many things on this.

Then the only choise is to enable PRIVATE number from your local telephone line provider. This is a feature that most of the telephone providers offer for free or for a small charge depending the company. I don't think there is another way to do that

All corrections applyed to the project page: http://www.electronics-lab.com/projects/rf/021/index.html

Hello FireFly You can buy a plastic insulator that is made exactly for the dimentions of TO-3 package transistor and has good heat transfer characteristics. The clear plastic you have is old type. You can also find other kind of matterials that are like rubber . Almost all electronics parts stores has it. I attach you also an image that saws how to use it. Regarding the "Heat Transfer Compound" you can put it both sides of the mica isulator for better performance.

STK401 is pin compatible with the next models STK401-020 and STK401-050. The difference (with a fast view at datasheets) is the output power and max supply voltage. Are you searching a specific info for STK401-000? http://www.datadart.com/al/sanyo/STK401-020.pdf http://www.datadart.com/al/sanyo/STK401-050.pdf

For fast reference check the schematic I attach. The rest of the pins are not connected.

This company offers a CD catalog for free: http://www.amplicon.co.uk Have you found any other?

Ever wondered how a TO-3 transistor is from inside view? See below:

Here is a simple 10 channel light bulb sequencer circuit which you can build up to decorate your house. OPERATION The circuit consists of 2 sections: 1) Oscillator: The oscillator is built around IC555 wired in astable mode. The frequency of this oscillator is around 1 Hz (or slightly less than that) which can be increased further by decreasing the value of potentiometer VR1. The oscillator frequency determines the speed of effect. Higher the frequency, higher will be the effect speed. 2) Sequencer circuit: The sequential lighting of bulbs is achieved using Jhonson Counter IC 4017 which has 10 decoded outputs. The output of 4017 increments by one on rising edge of each clock pulse from IC555. In the circuit the fifth output Q4 of 4017 is connected to its reset pin to reset the sequence after every four clock pulses. Here only four channels are shown but it can be extended upto 10 channels using all the outputs of 4017. In this case the reset need to be connected to Ground. For channels less than 10 the output one greater than required number of channels should be connected to reset pin to reset the cycle as soon as counter counts one greater than the required channels. The output of 4017 drives the base of NPN transistors (BC547) through 1k resistors. The LED in the collector loop of each transistor indicates the active channel. The emitter current of each transistor further drives the gate of Triacs (BT139) thereby turning them ON and supplying power to the lamp loads. Those who have 120V AC mains in their countries can also use this circuit without any changes. Many number of bulbs can be connected in parallel on each channel provided the maximum load on each channel does not exceed 3500W for 220V operation and 1760W for 110V operation. NOTE: DO NOT TOUCH ANY COMPONENT OF THE CIRCUIT WHEN IT IS ACTIVE AS IT MAY BE AT A VERY HIGH POTENTIAL AND MAY PROVE FATAL. I DO NOT GIVE GURANTEE OF ANY KIND. EXPERIMENT AT YOUR OWN RISK. Author: kinjalgp