What are the "ground" on a electronic circuit? Answered

I have checked many schematics and on all of them I see GND (ground) and nothing going to the VSS of the power supply. Is GND mean that it's connected to the negative (VSS) or is it more complex than that? What I am supposed to do if a schematic have both negative and grounding? Thank you.

Question by sxdemon   |  last reply


how can i tell where the ground is on a pcb?

Modifying antenna on a radio need to make sure it is grounded to the board. How can I tell where the old antenna was grounded?

Question by    |  last reply


PCB Trace Width Questions

Hello instructioners, So i am working on a PCB to use my XBOX 360 power supply as a standard 12volt 16 amp without hacking it apart. I've taken the female plug from a dead Xbox and I've recreated the layout in ExpressPCB. my only issue is being that its 16 amps @ 12volts is the trace widths to hold that much power are ridiculously wide we are talking 7mm or there abouts. I used several different online calculators to determine trace width.  My question is..  how small can i get away with for traces and still get 16amps.. is there a way of bridging the front and back side of a 2side PCB to allow for more amperage on smaller traces? i am really at a loss here. since my PCB is set at 38mm by 38mm and the connector size is 27mm long by 23mm wide. with 7mm wide traces i can't connect all the power pins together and all the ground pins together and route them out. Now i realize the 16amps is max draw but i'd like to plan for a max draw situation that way i feel confident enough to not have to check it all the time to make sure its not melting. Below is an image of the current board in Express PCB the labeled Thru-hole are connections i will need to make for this all to work. the other remaining holes are for mounting the female jack securely. The three yellow boxed connections are 12v+ The three greyed boxed connections are gnd ENG is bridged to +5 to make the XBOX PSU provide 12v

Topic by jgosselin   |  last reply


Do crystal radio's work when 'digital radio' has taken over?

For the past couple of days I have been interested and reading about crytsal radios. Having many issues recently, I do know that our radio stations here in Australia went to 'digital' and they removed analog T.V, but I never heard anything about radio. I can still pick up AM radio stations on the radio or in the car, but are these signals sent differently that a crystal cannot pick up? I attempted 2 versions of a foxhole radio, no luck at all there. So I went to Jaycar and bought this: http://www.jaycar.com.au/productView.asp?ID=KV3540 This proper PCB, with a galena diode still does not work. It also doesnt use a ground. Unless my aerial needs to be bigger which I doubt! I am using a 30ft spreader aerial. Later today I will stand NEXT to a radio station building which is only 2km from here, if it does not work, then no crytal radio works over here anymore which would really suck! How could they remove it!? And if I am wrong about the crystal stuff, then im still mad that the analogue technology has been removed anyway. It should sit there for anyone to explore.

Question by AtomRat   |  last reply


can ATmega and pic microcontrollers communicate with the rx and tx pins?

Hi. i am starting a project that will involve about 4 small boxes that have simple switches and led's connected to them. they will then all be linked to an arduino but maybe later on i will replace the arduino with a pcb that has an ATmega chip on. same as my arduino, which has my custom program on. i would like as least wires as possible. so by using the receive(rx) and transmit(tx) pins i would only need 4 wires. power, ground, rx and tx. BUT. pic microcontroller chips are alot easier to program and are cheaper too. i would not be able to use a pic microcontroller to control them all at the central hub so i would need the arduino and pic chips to be able to communicate without problems. only sending basic commands like: 0001 0011 or LED 1 HIGH. i just thought i'd check it could be done before i buy my parts. if it can't be done is there any way to make it work or any cheap alternatives? thanks, Luke 

Question by ljarrald   |  last reply


Help. my xbox 360 wireless AA batt acid melted the ground wire connection on the controller. need help to make a new one

I have wireless xbox 360 controller, and using the removable AA battery pack. ( not the rechargeable closed solid battery pack ) after leaving the AA batteries in for a long time, the acid leaked out and actually melted the GROUND wire that is soldered to the PCB of the controller. i tried soldering a new wire on, but i'm guessing the point where the wire goes no longer is suitable as the controller still wont turn on. is there another place i can run the - (negative) part of the AA batteries on the PCB as im confident the normal place the ground wire goes to is screwed..... i was thinking can i connect it to the place the rechargeable battery pack connects to as it seems that it doesnt touch the same connectors as the AA battery pack. as the rechargeable pack has those small copper flat pins on the back of it.. which one is ground, can i use that connection? any help would be appreciated. photos of the place i can make my new ground connection would really help.... you can email me at tristan@platinumav.tv if you like, as i may not be able to check this site very often due to work. thanks for ur help all! Tris10

Question by Tris10   |  last reply


Mouse wheel. How do I replace optical encoder with rotary encoder?

Hi, I have a Belkin Nostromo N52 controller. It has a mousewheel that can be custom programmed independently from the wheel in your regular mouse. I want to use it as a jog dial so I want to remove it from the original place and replace the rubber wheel with a jog dial. Basically it is to rotate the wheel 90 degrees as they did here with a mouse: https://www.instructables.com/id/Desktop-Scroll-Wheel-and-Volume-Control/?ALLSTEPS The problem is the Nostromo wheel uses an optical encoder instead of a rotary encoder (the typical used by half of the mouse wheels in the world). The mod I want to do would be a little complicated using the optical encoder (I would have to use a piece of PCB perpendiculary soldered to the main PCB and the height of the resulting device would be very tall for what I want) but it would be very easy if I could replace the optical encoder with a rotary encoder I salvaged from a mouse since it can be laid down on the PCB pretty well. The problem is the signals of the optical encoder and the signals of the rotary encoder are different. The middle leg of the receiver in the optical encoder is connected to +5vcc while the outputs are connected to ground using 10KΩ resistors. In the rotary encoder, the first leg is connected to ground and the other two go directly to the mouse IC. I tried to remove the optical encoder of the Nostromo and connect the two outputs of the rotary encoder to where the outputs of the IR detector go and the third leg to ground but all I get is a permanently actived scroll down (as if the wheel was scrolling down all the time). I didn't dare to connect the third leg to Vcc just in case I blow the thing. I think there must be a way to replace the optical encoder with a rotary encoder and get the same signals and I think this involves using the Vcc line and resistors but since I'm not very good at the electronic side of things, I don't know how to do it. I'm enclosing a diagram of the optical encoder circuit. The diagram on the right enclosed in question marks is what I guess would be the equivalent circuit for the rotary encoder but I'm not sure. Can anybody confirm it or point out the appropriate corrections? Thank you.

Topic by jedikalimero   |  last reply


How to control Stepper Motor with Integrated Controller, with Arduino

I salvaged a few big stepper motors from a large Laser printer. Unfortunately they all have integrated controller boards. I would like to control them with an arduino. I am aware that an option is to remove the PCB then use a regular contoller. I would prefer to use the integrated board. The boards have the following inputs: 24V GND P/S LD CLK +5 GND The high and low voltage and ground are obvious. CLK is the clock speed (which I half understand). LD is Load?? P/S is pulse?? The board has an SLA6024 with a nice heatsink. (perhaps that helps. I am after a wiring diagram and arduino sketch to control the motor for a CNC machine. Your help is appreciated. Attached are a few images.

Topic by craigevert   |  last reply


Can I tap into these audio circuits by desoldering Op-Amps and putting wires in their place? Answered

In my continuing quest to make an under-cabinet kitchen radio (see Chapter 1, Chapter 2, and Chapter 3), I'm looking at the original PCB for the boombox I'm hacking. Based on the work of three predecessors (Convert a radio tape player..., How To Make A Audio... and Play and Recharge Ipod...) I'm looking at ways to bring in audio from two sources.  I'm putting in a CD-ROM drive to be my CD player, and I'm adding a headphone jack for my BlackBerry so I can listen to MP3s, Pandora, and streaming radio. It appears that there are two ICs that act as preamps in the boombox, one for the CD portion, and one for the cassette.  See the pictures for where they are located on the board.  Photos 3 and 4 are pinouts for these ICs as found online. I want to remove the BA4558 and solder in a connecting cable for the audio out from the back of the CD-ROM: Left to OUT1 on the board, Right to OUT2, and ground to VEE. Likewise, I want to remove the BA3308 and solder in a cable with a male 1/8" headphone jack to plug into the BlackBerry.  Left to OUTPUT1, Right to OUTPUT2, and ground to GND. Then I'll be able to switch the selector from the boombox to CD and play CDs, and to Cassette and listen to the 'Berry. Will this work?  What are the likely pitfalls?

Question by yoyology   |  last reply


designing an LC4/LC5 package for mm-devices using Eagle CAD tools?

Hello every one, Since i am totally new to PCB designing and all these stuff, I want to know few things about Eagle CAD tools I will be designing a Frequency up-donwn converter as a University course project. out of many components selected for this project one of them is as follow. http://www.hittite.com/content/documents/data_sheet/hmc523lc4.pdf i have gone through designing of the LC4 package, i hope it would be fine, still i would like to know how to creat ground of a package, creating outline boundries of package (is it from wire or from rectangle, polygon??) and about symbols inside this package, i am confused about drawing them exactly and connecting them to each other (via wire or net or what??), should they be just symbol or e.g i have to draw even what is inside circuit of a mixer or amplifier etc.. I shall be very much thank for your kind help

Question by lali2 


Little Gem Guitar Amp Questions

I recently went to build the Little Gem guitar amp from runoffgroove.com. Its a great little amp from what i have read. I made the basic heart of it so far. I have the four caps, resistor, IC socket, and its all connected. I think basically all thats on the breadboard for the PCB layout here: http://runoffgroove.com/littlegem.html(scroll down). I'm confused on where to put the two pots and connect power and all that. I don't have the gain pot yet, but i do have the 25 ohm rheostat. The rheostat has three prongs, would i use the middle leg for the "out" part and the other two for the other part? I can't seem to get it. Also, is there a common ground between the input from the guitar, the 9v battery, volume pot, and output? Help please!Update:I found a layout on Flickr that explains it, i think. See the third picture.

Topic by John Smith   |  last reply


Heat sink mystery

While harvesting parts from a tiny refrigerator, I found something that I don't understand. There was a heat sink about 6 inches square on the back with a 12v fan attached. Underneath this arrangement was a smaller heat sink about 3 inches square and sandwiched between the two was an aluminum block, also 3 inches square and about 1/2 inch thick. Between the block and the large unit is what appears to be a ceramic tile about 2 inches square, seperated from the larger sink with a thin layer of white foam. This tile is glued very securely to the back of the larger heat sink. What puzzles me are the two wires running from a PCB to the ceramic tile. They disappear into the foam but I can't tell what they connect to. A heat sensor that is attached to the large sink, perhaps? There was a twist knob inside the unit that allowed you to adjust temperature from Min to Max. I don't want to pry off the tile just yet in case this might be something useful in its current condition. This refrigerator is probably more of an ice chest than anything, else. There are no coils on the back and no compressor. The only motor is what drove the fan. There is a drip pan on the back and what looks like a plastic hose connection but I don't know if this tube let water in or out. The whole refrigerator is only about 2 feet cubed. It was powered by a standard grounded AC cord. How did this thing cool? And what do those mysterious wires under the ceramic tile serve?

Topic by Boy Genius   |  last reply


I need arduino code help. Answered

I have a code for my robot and when i try to compile it I get an error. error expected unqualified-id before 'if ' here is the code // Connections to the Tumber PCB // // Arduino : Tumbler // pin 9 ---- pin 6 // pin 10 --- pin 7 // pin 3 ---- pin 11 // pin 11 --- pin 10 // ground --- pin 2 (ground) // // int inputVariable = HIGH; // sets input to high int RightFwd = 3; // PWM Output to go Foward on Right Wheel int RightRev = 11; // PWM Output to go Reverse on Right Wheel int LeftFwd = 9; // PWM Output to go Forward on Left Wheel int LeftRev = 10; // PWM Output to go Reverse on Left Wheel int delaytime = 2000; // delay between steps int speedval = 145; // speed forward and reverse, at 50% (of 255 max) void setup() { pinMode(inputVariable, INPUT); // Sets the digital pin as input inputVariable = digitalRead(2); // Right bump switch on pin 2 digitalWrite (inputVariable, HIGH); // Sets the pin to high pinMode(RightFwd, OUTPUT); digitalWrite(RightFwd, LOW); // Make sure Output is initally at LOW pinMode(RightRev, OUTPUT); digitalWrite(RightRev, LOW); // Make sure Output is initally at LOW pinMode(LeftFwd, OUTPUT); digitalWrite(LeftFwd, LOW); // Make sure Output is initally at LOW pinMode(LeftRev, OUTPUT); digitalWrite(LeftRev, LOW); // Make sure Output is initally at LOW delay(delaytime); } void loop() { analogWrite(LeftRev, 0); analogWrite(LeftFwd, speedval); // turns on the left wheel in forward direction at the speed value analogWrite(RightRev, 0); analogWrite(RightFwd, speedval); // turns on the right wheel in forward direction at the speed value delay(delaytime); analogWrite(LeftFwd, 0); // turns off the left wheel analogWrite(RightFwd, 0); // turns off the right wheel delay(delaytime); } if(inputVariable == LOW); } analogWrite(LeftFwd, 0); // turns off the left wheel analogWrite(RightFwd, 0); // turns off the right wheel analogWrite(LeftRev, 0); // turns off left wheel analogWrite(RightRev, 0); // turns off right wheel analogWrite(LeftRev, speedval); // turns on left wheel rev analogWrite(RightRev, speedval); // turns on right wheel rev delay(800); // 800 milliseconds analogWrite(LeftRev, 0); // turns off left wheel analogWrite(RightRev, 0); // turns off right wheel analogWrite(LeftFwd, speedval); // turns on left wheel analogWrite(RightFwd, speedval); // turns on right wheel } I bolded the line that the error comes up on

Question by TOCO   |  last reply


mini 5gb hitachi hdd re-purpose/integrate into speaker system (LOTS OF HELP lol)

Well, where to begin? I have a 5gb hitachi microdrive sitting in my lap right now, and i was thinking of possible  uses. ironically the idea I came up with is pretty much exactly what it came from. mp3player lol. I do have the rest of the mp3, which to my knowledge has no damage except a removed screen that was shattered many moons ago. So i shouldnt have to format it or anything.  ~Can I adapt some other random lcd screen/ externally operate via laptop or phone. ~could it be integrated into an amplifier circuit so that i could hook speakers up direct ~if yes ^ would any of you fine specimen be willing to either guide, or send me links for a VERY simple beginner amplifier circuit. (i dont have an LM386 taken apart tons of stuff, cant find one. and i am very much so a beginner.) ~ are there ANYYY ideas for possible other uses/configurations. I have an arduino but ive yet to begin study (on the grounds that I believe I should start with basic components and circuits b4 code) ~i have questions for dayysss.. would anybody care to do a little tutoring here and there when I have questions? Im no dumby, but I am just beginning so patience may be required, along with a casual tongue.  ~lastly, im poor. I mean like REALLY poor, donations? lmao no jk jk jk. however Im unable to purchase anything at all. I do on the other hand have a mismatched selection of harvested pcb's littered with the good stuff, so if given ample time and alternatives I may posses the required component.                                                                                                                                                                           Much appreciated,                                                                                                                                                                                  Codyb816

Question by cdb816   |  last reply