hybridfree/eevblog-posts huggingface dataset:
Buying Rigol Logic Analyzer probs - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: March 19, 2019, 02:48:47 pm
content: Hi, There are some used Rigol Logic Analyzers available on some sites, they comes without logic analyzer probsI hardly found one place where i can buy those probs, but they are too expensive like $350 when i add price of probs to logic analyzer price there is no sense to buy used analyzerI want to know is there some source where i can buy cheap probs for rigol logic analyzer or is there something else that can help on this.thanks

author: thm_w
author_rank: Super Contributor
timestamp: March 19, 2019, 08:49:47 pm
content: Rigol doesn't sell standalone logic analyzers, so you must be referring to one of their mixed signal oscilloscopes (MSO).There are some projects to build your own probes, but it depends on what oscilloscope you have:https://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/Generally you will be better off getting a standalone USB logic analyzer (a good one is less than $300).

author: TK
author_rank: Super Contributor
timestamp: March 19, 2019, 09:46:08 pm
content: If you need to analyze parallel bus with 8, 16 or more bits, then you can buy a legacy HP/Agilent logic analyzer for around $200 (agilent 1670E / 1670G is an excellent option).

author: nucleopolymere
author_rank: Contributor
timestamp: March 20, 2019, 10:18:23 pm
content: https://www.ebay.ca/itm/USB-Logic-Analyzer-Device-Set-Compatible-to-Saleae-24MHz-8CH-for-ARM-FPGA-M100/253841718379?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20180816085401%26meid%3D69e8a3696025462dba8b9ebd94c372a3%26pid%3D100970%26rk%3D1%26rkt%3D15%26sd%3D253841718379%26itm%3D253841718379&_trksid=p2481888.c100970.m5481&_trkparms=pageci%3A74de2daa-4b5d-11e9-b07e-74dbd18009d4%7Cparentrq%3A9d2b0ad61690a9e3aa97a320fffdddb8%7Ciid%3A1Have bought this one 1 year ago, its crazy cheap and it served me well to troubleshoot serie communications. I don't know if it suits your needs though
Buzzer current limiting resistor value - Page 1
Forum section: electronics / beginners

author: BarakG
author_rank: Newbie
timestamp: October 29, 2018, 08:14:13 am
content: HelloI would like to know how did the circuit designer of the circuit in the image calculated resistor R100 value.I have tried to figure it out by myself but I'm not sure about it. I would like to know if my calculations are right.My guess is that the 100ohm resistor is to limit the current to ~20mA.buzzer's datasheethttp://www.puiaudio.com/pdf/SMT-0540-S-R.pdfThe buzzer's datasheet says that Vp-p = 3V, Imax = 100mA.To use Ohm's law to calculate R100 we have to 'translate' Vp-p to Vrms (kind of avg voltage) so,Vrms = 0.35355 * Vp-p = 1.06V.Then by Ohm's law:R100 = (3.3 - 1.06) / 0.020 = ~100Ohm.My calculations are right?

author: ArthurDent
author_rank: Super Contributor
timestamp: October 30, 2018, 02:32:59 am
content: This is the way I see it.The driving signal is specified as a square wave on the data sheet and it is used to turn the MOSFET on or off like a switch. The spec sheet says the buzzer has a resistance of 12 ohms with a maximum current rating of 100 MA. With the series resistor of 100 ohms and the buzzer resistance of 12 ohms, when the MOSFET is on, you have 112 ohms across a 3.3 VDC supply which gives you about 29 MA. That gives about a .35 VDC drop across the buzzer and about a 2.9 VDC drop across the resistor.To drive the buzzer with the maximum current you would need a 21 ohm resistor, in series with the 12 ohm buzzer, or 33 ohms across the 3.3 VDV supply to give you 100 MA. Apparently this would produce far to loud a tone for this application so the circuit design drives the buzzer at less than a third of the maximum current.
Buzzing sound in class D audio amplifier - Page 1
Forum section: electronics / beginners

author: Riyas8123
author_rank: Newbie
timestamp: March 23, 2021, 09:01:06 am
content: I have a PAM8403 audio amplifier which is a class D amplifier. But I hear a buzzing or cracking sound only noticable at high volumes.So far I have done the following steps:1. Tried to add a capacitor at input to provide surge current.2. Added a simple capacitor in series to help the audio get rid of DC. Even though the board has one.But I dont know what else to try.

author: cheater
author_rank: Regular Contributor
timestamp: March 23, 2021, 03:46:02 pm
content: This is a tiny circuit - are you sure you're not exceeding its power handling capability?

author: Jwillis
author_rank: Super Contributor
timestamp: March 24, 2021, 01:32:51 am
content: In the application note 2 on page 7 of the datasheet it says "When the PAM8403 works without LC filters, it's better to add a ferrite chip bead at the outgoing line of speaker for suppressing the possible electromagnetic interference. "
Buzzing Sound on Radio - Page 1
Forum section: electronics / beginners

author: lightray03
author_rank: Newbie
timestamp: January 06, 2015, 12:55:09 pm
content: hello i have a problem on my radioit creates a buzzing sound when turn on or even when turn offand my suspect is the Amplifier TA8227, i tried to replace the filter capacitor and the problem on having buzz sound when turn off is now gonebut the buzz sound when on radio mode and cd mode doesnt gonei hang also the inputs at pin 6 and 7 and the amplifier still creates buzzing sound(even having no inputs)what should i do next? can someone help me please im still a beginner

author: madires
author_rank: Super Contributor
timestamp: January 06, 2015, 01:51:29 pm
content: Is it a 100Hz (for 50Hz mains) or 120Hz (for 60Hz mains) buzz?

author: lightray03
author_rank: Newbie
timestamp: January 06, 2015, 01:56:47 pm
content: its a 100hz buzz

author: madires
author_rank: Super Contributor
timestamp: January 06, 2015, 02:14:51 pm
content: I'd check the filter caps in the power supply.

author: lightray03
author_rank: Newbie
timestamp: January 06, 2015, 02:38:26 pm
content: i already check the filter caps and replace it with a new one, the standby mode or the off state doesnt output buzzbut when turn on the buzz still exist

author: madires
author_rank: Super Contributor
timestamp: January 06, 2015, 04:42:54 pm
content: I see. Maybe someone else got another idea.

author: mij59
author_rank: Frequent Contributor
timestamp: January 06, 2015, 05:16:28 pm
content: Hi,Measure the dc voltage at the output of the amplifiers, pin 2 and 11, should be about 1/2*VCC1.Check the voltage VCC2.

author: katzohki
author_rank: Frequent Contributor
timestamp: January 06, 2015, 05:19:46 pm
content: Post what pictures / circuit diagrams you can for us to better help.

author: Strada916
author_rank: Frequent Contributor
timestamp: January 11, 2015, 01:07:20 am
content: Ground loop........?
Bypass capacitor for screen grid? - Page 1
Forum section: electronics / beginners

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: January 26, 2020, 10:14:53 pm
content: I don't really know what the screen grid does but I have heard that the resistor value changes the sound a bit so I figured that a bypass cap would also change the tone?how much would it change it and also can someone explain what exactly the screen grid does?

author: David Hess
author_rank: Super Contributor
timestamp: January 27, 2020, 09:24:47 am
content: The screen grid shields the control grid from the anode (plate). This has the effect of both raising the anode (plate) resistance and reducing the capacitance between the anode (plate) and control grid so higher gain and higher frequency operation is possible. It performs the same function as a cascode output transistor in a two transistor amplifier.https://en.wikipedia.org/wiki/Tetrode#Screen_grid_valve

author: TimFox
author_rank: Super Contributor
timestamp: January 27, 2020, 03:10:04 pm
content: To first order, the screening effect of grid 2 (held at a constant voltage with respect to the cathode) makes the electric field at the cathode almost independent of the plate-cathode voltage (extremely high mu, hence the large plate resistance). In normal pentode operation, the screen bypass capacitor helps maintain the screen-cathode voltage even as the screen current changes with plate voltage. Note that changing the screen voltage on purpose does change the cathode current: there is a “screen mu” parameter that describes the triode behavior of the cathode-grid1-grid2 portion of the pentode. This parameter is generally low (e.g. 4.5 for a 6146 power tube). Therefore, if the screen is powered through a resistor, with no bypass capacitor, the stage gain is reduced: see any tube textbook for details.
Bypass Capacitors and Switching Voltage Regulators - Page 1
Forum section: electronics / beginners

author: willindsey
author_rank: Newbie
timestamp: August 19, 2020, 02:38:23 am
content: Hi!I am making a power circuit to step down a 12V DC battery to 5 Volts for powering a few usbs. I am planning on using 2 LM2678 switching power converters to supply power to 4 USB ports each. I understand that due to the differences in output voltage and current between the two regulators one can not put this particular model in parallel. I was wondering if you can share the same Bypass Capacitors on the 12v input and cut back on the total number of bypass capacitors on the circuit? Thinking the problem through, my initial answer is no since the higher current draw of having two regulators would discharge the capacitors quicker and effect their ability to smooth out the input voltage. Is there a happy median or will I need to follow the datasheet to a tee? Oh I am using the LM2678 regulators as I already have a bunch on hand.Thanks!

author: bob91343
author_rank: Super Contributor
timestamp: August 19, 2020, 06:27:47 am
content: You can use a single bypass capacitor. You may or may not need to use a larger value. Try it.

author: Vovk_Z
author_rank: Super Contributor
timestamp: August 19, 2020, 09:26:07 am
content: If you (I mean TS) are talking about a bulk bypass cap then it can be one of cause. If you talk about small ones (sub microfarad) then it is much better if they are placed very close to an circuit input. The closer to the IC - the better.The IC itself does not need good bypass (and will work with any) but the radiated common and differential noise will differ very much.
Bypass capacitors, are either ceramic or poly film OK? - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: January 29, 2015, 10:37:12 pm
content: Is there a reason to choose either poly film or ceramic for bypass caps? I acquired a good stash of poly film caps at a rally, so could I use them, for example, for the bypass caps of 220nF in this circuit. Or should I get ceramics? Thanks. Note some bypass caps are shown with an asterisk to save schematic real estate.

author: tggzzz
author_rank: Super Contributor
timestamp: January 29, 2015, 11:01:47 pm
content: The key characteristics required for decoupling capacitors are low inductance and low series resistance at the frequencies of interest. How low and what frequency are application dependent.In general ceramics are likely to be better, but that's not absolute.

author: wraper
author_rank: Unknown
timestamp: January 29, 2015, 11:08:47 pm
content: Depends on how particular film capacitors are made. Some may not be suitable for decoupling.

author: katzohki
author_rank: Frequent Contributor
timestamp: January 30, 2015, 12:01:15 am
content: I would tend to lean towards ceramics, but poly film "should do". Depending on the frequency and signal level of your circuit of course. For "general purpose" applications I wouldn't see a problem.

author: c4757p
author_rank: Super Contributor
timestamp: January 30, 2015, 12:04:44 am
content: Use ceramic for digital. Digital devices take sharp current spikes and require low-inductance decoupling. Stacked film capacitors will work in a pinch, but rolled ones will not.Well, they'll "work" in the sense that that circuit wouldprobably"work" without any local decoupling at all. They'd hardly help though.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 30, 2015, 09:20:52 pm
content: Won't make a lick of difference.
Bypass usb speaker when headphones are plugged in. - Page 1
Forum section: electronics / beginners

author: mwarner416
author_rank: Newbie
timestamp: August 27, 2015, 02:16:15 pm
content: Hello,I have a 6 year old son that apparently has to have his computer speakers on full blast to enjoy computer time. So instead of buying a new set of speakers with a 3.5mm jack I thought I would add one. But my question is, I am not sure what kind of jack to get and honestly the only local electronic store near me would be radio shack. I have been doing a little searching on their site and found some 3.5mm panel phone jacks, but I don't know if I need one that is open circuit or closed circuit.I am assuming I would need a closed circuit. Could someone please enlighten me, also please note that I am new at this.

author: klunkerbus
author_rank: Unknown
timestamp: August 27, 2015, 03:34:06 pm
content: Yes, a closed circuit jack is what you're looking for. I'd personally look for jacks at an on-line source like Mouser or DigiKey, hoping for something with better quality than what you get at Radio Shack. These small jacks are easily damaged, especially with kids in the loop.It can be challenging to figure out the pinout on the jacks. The ones from the likes of Mouser and DigiKey would also likely have a datasheet available. Hopefully the one from Radio Shack has a pinout diagram on the package. If not, you may end up spending time with a multimeter figuring out the pinout by checking for contact connections with the plug inserted and the plug removed.
Bypassed emitter on Common Emitter Amplifier - Page 1
Forum section: electronics / beginners

author: Moriambar
author_rank: Unknown
timestamp: April 11, 2020, 03:04:21 pm
content: Hi,Reading the AoE, I never stop to be puzzled by my lack of understanding.A common emitter amplifier with a gain of 50 and bypassed emitter resistor is presented (page 97, fig 2.50), also:Its requirements are a quiescent current of 1mA and to operate between 20Hz and 20kHzThe text proceeds indicating many things that I don't understand.First it says that the bypassing capacitor value has been chosen to be small than re(the intrinsic emitter resistance) at the lowest signal frequency. reshould be around 25due to the 1mA collector current.But calculating Xc= 1/(2pi f C)= 1/(2*pi*20*68*10-6)=106*1/8545≈117which is way bigger than re. Where am I wrong?Second it says that the gain is set by the first emitter resistor (180) plus re. Why is that so? I don't understand why the 820paralleled with the capacity does not count (although it counts for the quiescent current).Third it's fig 2.51 (which is also in the attachment above). I understand that only the 1k resistor will set the quiescent current; I appreciate that the bypassing side will prevail at signal frequencies, but I cannot understand how this can be equivalent to the circuit before.Any help is appreciated, I passed the last hour and half trying to understand this with no luck

author: Paul Rose
author_rank: Regular Contributor
timestamp: April 11, 2020, 03:33:44 pm
content: I have the older edition, but it has the same example.The text there says "the emitter bypass capacitor is chosen to have low impedance compared with 180+25 ohms at the lowest signal frequencies".Your 117 ohm calculation for 68uF at 20Hz is correct, but it is small compared to 205 (180+25). Consider that the 68uF cap impedance is already down to 23.5 ohms at 100Hz, and don't be too picky about a gain of exactly 50 at 20Hz.For your second question, gain is set by 180 + re. This is because at signal frequency, the 820 ohms is paralleled by the 68uF cap. At the lowest signal frequency, this will reduce the gain somewhat (down to 35 if I did it right). Over most of the frequency range, the 820 will be practically shorted by the 68uF cap.Also consider that the lowest gain of 35 at 20Hz is 70% of the target gain of 50. This is probably no coincidence, because a voltage ratio of 0.7 is very close to 3db, which is often the value used to measure the usable range of an amplifier.The quiescent is determined at DC. The cap is "open" at DC, so the 1k = 820+180 is used.

author: Moriambar
author_rank: Unknown
timestamp: April 11, 2020, 05:29:29 pm
content: Quote from: Paul Rose on April 11, 2020, 03:33:44 pmyou are right. I don't know what my brain was reading.thanks
Bypassing lamp detection circuitry - Page 1
Forum section: electronics / beginners

author: bea
author_rank: Newbie
timestamp: June 13, 2014, 12:06:01 pm
content: Hi everyone,I'm having a problem with my video projector. The lamp went off, I want to replace it with a pcb with LEDS. The problem is that I need to bypass the lamp detection circuitry so that my new lamp can work with the motherboard. I know I have to cut off two wires and connect two others to bypass the detection,I think it's the yellow or the blue one ( on the 2nd picture, the one removed). But I 'm not sure.... My projector is a canon sx6. Here's some picture of it. If anyone could give some help, it would be fantastic. Thx a lot.

author: HalfSpace
author_rank: Regular Contributor
timestamp: June 14, 2014, 11:55:59 pm
content: Hi Bea,A circuit diagram or block diagram of the unit would help. If not available, can you remove the lamp assembly and post some pictures of the wiring to it?I would think that brightness level and over temperature is all that is monitored at the lamp assembly and the current drawn by the lamp is monitored on the main PCB.HalfSpace
BYV32E-200 vs BYV32E-200P - Page 1
Forum section: electronics / beginners

author: essence25
author_rank: Newbie
timestamp: February 03, 2020, 11:19:40 pm
content: Hello lads,Question,Are these the exact same parts, original BYV32E-200 vs the mouser.com one which has a "P" at the end. Eg. BYV32E-200P can the P one be used in place of the non P?Thank you!

author: ArthurDent
author_rank: Super Contributor
timestamp: February 04, 2020, 12:14:02 am
content: It looks like the 'P' version has an isolated mounted plate but the non P has the cathode connected to the mounting plate.Athttps://www.digipart.com/part/BYV32E-200scan down to the Arrow listing and click on the part numbers for more information.

author: george.b
author_rank: Frequent Contributor
timestamp: February 04, 2020, 01:29:22 am
content: Quote from: essence25 on February 04, 2020, 01:15:55 amYes.

author: ArthurDent
author_rank: Super Contributor
timestamp: February 04, 2020, 01:40:28 am
content: The 'P' version should work fine with or without the pink insulator. The checker shows that the original parts is probably O.K..

author: essence25
author_rank: Newbie
timestamp: February 06, 2020, 04:57:30 am
content: Ok, I received the new part with the P and it is exactly the same. Tab still tied to center pin. It appears to be a newer model and works fine in place of the old one. Even though the old one is not dead. :-)
c code example - Page 1
Forum section: electronics / beginners

author: alizare368
author_rank: Regular Contributor
timestamp: April 18, 2018, 11:16:03 am
content: HiHow can I write code in the keil as a registery for pin?c code example for led on and off?

author: mbless
author_rank: Regular Contributor
timestamp: April 18, 2018, 05:26:05 pm
content: Stop with the duplicate postsThis is your third post asking for code!Nobody here is going to do your homework for you. You have to at least say what you have tried.

author: ataradov
author_rank: Super Contributor
timestamp: April 18, 2018, 05:39:33 pm
content: Or you might at least tell us what microcontroller you are programming.Well, based on previous posts, it is STM32F0. You seriously can't find a blinky example for one of the most common MCUs?

author: IanB
author_rank: Super Contributor
timestamp: April 18, 2018, 05:43:56 pm
content: The way an engineer would do this is:1) Get hold of a dev kit2) Read the documentation3) Experiment4) Experiment5) Experiment6) Repeat from step 2 as necessary7) ...
C Code Mismatched Comparison - Page 1
Forum section: electronics / beginners

author: t1d
author_rank: Super Contributor
timestamp: April 02, 2018, 06:39:54 am
content: Re:PIC12F683MPLab X 4.15XC8 1.45if ((tim_ct >= 1) && (tim_ct <= 3000)){select = 1;GP2 = 1;}Okay, I can find instructional information on the separate operands, but I can not find examples of how to combine them. This looks perfectly reasonable to me, but the compiler says it is a mismatched comparison. What am I missing? Or, how can I test tim_ct, to see if it falls within some range of values?Thank you so much, for you help.

author: JPortici
author_rank: Super Contributor
timestamp: April 02, 2018, 06:43:42 am
content: -post the rest of the code-use the code tagsgoogle search of "mismatched comparison" gives me this as first resulthttp://www.microchip.com/forums/m853261.aspxhow is tim_ct delcared? if it's a char then the problem is in (tim_ct <= 3000), tim_ct can never reach 3000..

author: t1d
author_rank: Super Contributor
timestamp: April 02, 2018, 06:47:18 am
content: Quote from: JPortici on April 02, 2018, 06:43:42 amYou were right on target... Not enough room for tim-ct to reach 3000. Reset, appropriately, and cleared. Thank you. On to the next error...
C Inputs & Outputs Issue( PIC18F) - Page 1
Forum section: electronics / beginners

author: ed_reardon
author_rank: Regular Contributor
timestamp: October 15, 2016, 09:41:50 am
content: Hi all,Numpty here is tearing his hair out.All I want this code to do is run in an endless loop, where RB0 is low I want the pulse to be faster than when RB0 is high.Code:#define _XTAL_FREQ 8000000 //set osc. frequency#include <xc.h> //include xc8 header#define PULSE LATAbits.LATA0 //define pin RA0 as PULSE pin#define DIR LATAbits.LATA1 //define pin AR1 as DIRECTION pin#define SPEED PORTBbits.RB0 //define pin RB0 as SPEED pinint main (){ADCON1 = 0xFF; //switch OFF Port-A ADCCMCON = 0xFF; //switch OFF comparitorsTRISAbits.RA0 = 0; //define A0 as OUTPUTTRISAbits.RA1 = 0; //define A1 as OUTPUTTRISBbits.RB0 = 1; //define B0 as INPUTDIR = 0; //Change value to '1' for reversed motorwhile (1) //inititalise while loop{if (SPEED == 1) {PULSE= ~PULSE; //Set PULSE toggle__delay_us(50); //Toggle pulse SLOW}else {PULSE= ~PULSE;__delay_us(5); //Toggle pulse FAST}}return 0;}Now I've written this all by myself (ha) and I'm very fresh at this with a combined C coding experience measured in only a few hours.Why does the RB0 show as a DigitalOUTPUTin the MPBLab simulator?Yours, expecting he's done something stupid!Ed.

author: Ammar
author_rank: Regular Contributor
timestamp: October 15, 2016, 09:46:49 am
content: Perhaps I am missing something, but it looks as if you have set RB0 to be an input by setting the TRIS register value bit to one. If you want it to be an output, set it to zero.

author: ed_reardon
author_rank: Regular Contributor
timestamp: October 15, 2016, 09:54:49 am
content: Sorry, I mistyped and confused the living lights out of myself.RB0 shows as a digital OUTPUT in MPBlab simulator!Sorry for the confusion, I'll edit the initial post!Cheers,Ed

author: ed_reardon
author_rank: Regular Contributor
timestamp: October 15, 2016, 10:27:24 am
content: The plot thickens, I've noticed the emulator maps this pin to a PWM status, not a basic I/O status.I'm guessing (and I'm very fresh to this) I need to swtich the pin to digital duty rather than PWM.I shall RTFM!Cheers,Ed

author: ed_reardon
author_rank: Regular Contributor
timestamp: October 15, 2016, 10:51:00 am
content: Think I've got it cracked, added PWMEN1 = 0xFF to the program.Well if this works I'm very impressed that I've diagnosed it myself, and understood enough of the datasheet to work out what I'm doing!Off to flash it and plug it in!Cheers,Ed

author: ed_reardon
author_rank: Regular Contributor
timestamp: October 15, 2016, 06:48:02 pm
content: Well I solved my own problem, and as such I've managed to take a product and modify it to do what I want to do by writing code and stuff!Hey, I know this is clown shoes stupid but coming after a few hours with zero knowledge and looking online for bits and pieces I'm chuffed! Now to rewrite the interface software....Well maybe not!To clarify the header should have the following code added in the main program:PWMEN1 = 0xFF; //switch OFF PWM moduleCheers,Ed.
C# program not working - Page 1
Forum section: electronics / beginners

author: abdullahseba
author_rank: Frequent Contributor
timestamp: June 10, 2015, 05:05:09 pm
content: Can any one help?I have an Arduino Mega sending the word "hello" to the computer via COM3.The C# program I wrote is supposed to display "The variable is set to true." if it received "hello".If it did not receive hello it will display what it received.The problem is when I run it, it displays "hello" which means it should have displayed "The variable is set to true."ThanksHere is the code:Code:using System;using System.Collections.Generic;using System.Text;using System.IO.Ports;namespace SerialTest{class Program{static void Main(string[] args){string[] names = SerialPort.GetPortNames();SerialPort p = new SerialPort("COM3");p.DataReceived += new SerialDataReceivedEventHandler(p_DataReceived);p.Open();string line;do{line = Console.ReadLine();} while (line != "quit");p.Close();}static void p_DataReceived(object sender, SerialDataReceivedEventArgs e){string data = ((sender as SerialPort).ReadLine());string data2 = "hello";if (data == data2){Console.WriteLine("The variable is set to true.");}else{Console.WriteLine((data));}}}}

author: Wilksey
author_rank: Super Contributor
timestamp: June 10, 2015, 05:15:13 pm
content: Try changing:Code:if (data == data2)toCode:if(data.Contains(data2))There might be some characters you are not seeing.

author: abdullahseba
author_rank: Frequent Contributor
timestamp: June 10, 2015, 05:22:02 pm
content: Quote from: Wilksey on June 10, 2015, 05:15:13 pmThanks it worked!how can I see hidden characters?

author: Wilksey
author_rank: Super Contributor
timestamp: June 10, 2015, 08:13:52 pm
content: print out the ASCII number value and look at the ASCII chart, if you go into debug and put a breakpoint you should be able to see the extra characters or the number value of them in any case, it is probably including the \r\n chars or one of them.

author: sacherjj
author_rank: Frequent Contributor
timestamp: June 10, 2015, 08:38:48 pm
content: You can also look at the appropriate Trim command to clean various white spaces from each end. I could tell you in Python, but it has now been years since I've been in the C# word.
C programming language sematics - Page 1
Forum section: electronics / beginners

author: BitsnBytes
author_rank: Contributor
timestamp: February 05, 2021, 02:30:24 pm
content: Hello!Recently I came across the term semantics in context of C programming language.I don' t understand the meaning. Anyone please???Regards

author: Electro Fan
author_rank: Super Contributor
timestamp: February 05, 2021, 03:38:03 pm
content: Below is a thread about semantics (vs syntax) that might give some insight (and possibly add some confusion), but for a simple, high level, conceptual answer these definitions from a post in the thread might be a useful starting point:Syntax is the grammar of a language - the rules by which to form sentences or expressions.Semantics is the meaning you are trying to express with your code.https://stackoverflow.com/questions/209979/are-semantics-and-syntax-the-same/210044#210044

author: Cerebus
author_rank: Super Contributor
timestamp: February 05, 2021, 03:44:17 pm
content: It's a term from general linguistics, applied to the much narrower field of programming languages. Semantics is about themeaningof language, as contrasted with studying thestructureof language which is calledsyntax.In programming languages it's generally used to describewhat will happenif you use a particular program construct, that is, how it will be executed by the computer being programmed.

author: BitsnBytes
author_rank: Contributor
timestamp: February 05, 2021, 03:49:06 pm
content: OK thanks.I will have a look.

author: Electro Fan
author_rank: Super Contributor
timestamp: February 05, 2021, 03:56:30 pm
content: It starts out easy and then gets deeper and wider. The trick is to find what you are looking for that is accurate and that speaks to you in a way that enables you to absorb it and apply it when you need it.Might be something in here that will help you see a view that will help you:https://www.researchgate.net/publication/2822951_The_Semantics_of_the_C_Programming_Language

author: BitsnBytes
author_rank: Contributor
timestamp: February 06, 2021, 08:31:38 am
content: Quote from: Electro Fan on February 05, 2021, 03:56:30 pmThank you so much, it's a great help!Regards
c102 transistor Equivalent - Page 1
Forum section: electronics / beginners

author: user_404
author_rank: Newbie
timestamp: April 30, 2013, 02:27:45 am
content: hi can any one tell me what is the equivalent of the c102 transistor please, i can't find it any were

author: Bored@Work
author_rank: Super Contributor
timestamp: April 30, 2013, 05:43:11 am
content: Quote from: user_404 on April 30, 2013, 02:27:45 amTry 2SC102, which should be the full name of that transistor.
C556 and C546 transistor - Page 1
Forum section: electronics / beginners

author: jmctech
author_rank: Contributor
timestamp: February 27, 2018, 02:57:43 am
content: Hello,I have been tasked with trouble shooting a board for a obsolete machine, the board controls a couple of motors, looks like current limiting resistors for the motors failed short and over loaded the main transistors (bvd64b & bvd67A) and these transistors pictured which were hooked to the base of the main transistors. My question is, I was able to find c546 transistors in a cross reference, but all I can find for the 556 is BC556. I have not been able to find any info on a c556. Are these BC### and the B is just not on the case? Or are they different?Sent from my SAMSUNG-SM-N920A using Tapatalk

author: amspire
author_rank: Super Contributor
timestamp: February 27, 2018, 03:03:03 am
content: It is the BC546 (NPN general purpose) and BC556 (PNP general purpose) transistors. Originally designed by Philips.

author: jmctech
author_rank: Contributor
timestamp: February 27, 2018, 05:20:56 am
content: Quote from: amspire on February 27, 2018, 03:03:03 amThank youSent from my SAMSUNG-SM-N920A using Tapatalk

author: Peabody
author_rank: Super Contributor
timestamp: February 27, 2018, 06:17:23 am
content: Could be 2SC546 and 2SC556.

author: amspire
author_rank: Super Contributor
timestamp: February 27, 2018, 06:30:31 am
content: Quote from: Peabody on February 27, 2018, 06:17:23 amThey are Philips BC546/556. I have a some Philips BC557B transistors with the silvered front and the same PH code.
CA810 7W Power Amp Circuit - Page 1
Forum section: electronics / beginners

author: vidarr
author_rank: Frequent Contributor
timestamp: March 05, 2020, 04:16:46 pm
content: I have two of these CA810 (QM) amps that I want to build circuit(s) for. The "test" circuit on the datasheet seems OK, but maybe there is something better? Searching didn't bring up any other circuits. Does anyone have a circuit for this, or maybe build this already and share their circuit?The plan is to build everything from scratch, including the housing -- everything. So, I want to make this as nice as I can.Thank You
Cabeling PSU for "best" precision? - Page 1
Forum section: electronics / beginners

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 07, 2019, 02:16:19 am
content: I have a DC PSU (max 15V 60A, 0.1mV 0.1mA resolution with 5½ display and with 5V sense lines.)I know that shorter cables with bigger diameter is better but how much does matter, within reason?My question is most if I can place the PSU on the top shelve and run the cables the 10 feet "long" way round or I shall place the PSU on bottom shelve, 2 feet right above the work table?What thickness is best for the power/sense lines, shielded, twisted, more?My goal is not to compete with NASA but I would like to know that what I send is what I end up delivering. :-)

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 07, 2019, 03:05:41 am
content: Great advice, and thanks for the math!Before I did ask, I did think of making one cable with the sense (yes real s+ s- lines) but then I found out that a 60A maybe shall be about 4 awg, so wary thick or?That gave me the idea to run them separate so I can use whatever I need in awg and the sense lines parallel.I was thinking on using crocodile clamps.After your answer, am I not sure that it is any good?

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 07, 2019, 03:42:07 am
content: Thanks again, cant seme to find anything about voltage drop, would you please take a look?http://www.maynuo.com/downloadfile/2009102937237341.pdf4x cable, so 6 wires in total?

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 07, 2019, 04:13:21 am
content: yes my bad:-)Ok thanks I'll ask!Is 10 wires better then 4 (2 power + 2 sense) ?

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 07, 2019, 04:32:03 am
content: yes that makes sense! :-)How would you terminate the cables, in alligator or?

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 07, 2019, 05:17:56 am
content: I am so happy that you help!Yes if I need 60A we are talking about using different connectors, but I am thinking for powering generic DUT where there are no high amp input.

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 07, 2019, 07:57:17 am
content: I have got the following answer, that I do not understand.The compensate voltage is 05V~1V. A higher voltage has a higher compensated voltage.

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 07, 2019, 08:28:21 am
content: Quote from: blueskull on May 07, 2019, 08:01:02 amLOL so I may have to ask again:-)
Cable Diameter measurement - Page 1
Forum section: electronics / beginners

author: EEVaditya
author_rank: Regular Contributor
timestamp: April 07, 2018, 09:42:21 am
content: Hello,How to determine the AWG of a wire ?

author: frozenfrogz
author_rank: Frequent Contributor
timestamp: April 07, 2018, 09:58:29 am
content: https://en.wikipedia.org/wiki/American_wire_gauge

author: Ian.M
author_rank: Super Contributor
timestamp: April 07, 2018, 10:20:58 am
content: Once you have an AWG table with diameters handy, you need to make the actual measurement.For stranded cables and larger wires, vernier or digital callipers are suitable. If the wire is insulated, cut round the insulation and pull it partially off (or cut round a second time and peel off the insulation between the cuts) to expose a ring of the bare wire to make the diameter measurement on, with the end still trapped in the insulation so the lay of the strands isn't disturbed. Avoid twisting the exposed section as you work.For fine wires you need a micrometer. For fine stranded wires, count the strands and measure a few individually and take the average. For greatest accuracy, magnet wire should be chemically stripped to remove the enamel.You can get AWG gauge plates, which are useful for larger wires and cables when great accuracy isn't needed, but make sure you get one from a reputable supplier that is actually marked as being for AWG wire, as there are many cheap ones on EBAY and similar which are either misdescribed as AWG gauges or have incorrectly sized gauging notches.

author: tooki
author_rank: Super Contributor
timestamp: April 07, 2018, 03:48:59 pm
content: But isn’t the AWG of stranded wire a function of itstotalcross-section, not the diameter of the bundle?!? My understanding is that different strandings of the same AWG may have different actual diameters. As such, my understanding is that only solid (not stranded) wires can have their cross-section or AWG determined correctly by measuring the diameter.

author: Ian.M
author_rank: Super Contributor
timestamp: April 07, 2018, 06:25:05 pm
content: Yes, that's right, but for simple spiral laid stranded wire you can get pretty close by assuming 10% voids, and as the area is proportional to the square of the diameter, multiplying the measured diameter by 0.95 before looking it up is good enough for most purposes. However this breaks down for low strand counts and more complex layups that leave voids between bundles of strands. and in those cases you should dissect it, count the strands and use a micrometer on a few of them then look up the total copper CSA, not the diameter.
Cable Harness Tester - Any literature, resources? - Page 1
Forum section: electronics / beginners

author: japasetelagoas
author_rank: Regular Contributor
timestamp: April 01, 2019, 05:23:28 pm
content: Hi everyone.I'm thinking about developing a project of a cable harness tester to be used in the company where I work at.We build a wide variety of products focused on the transportation market (locomotives) and as expected, there are tons of cable harnesses with several different plugs and receptacles.There's this company called Cami Research that sells a cable tester where you can switch its input and output modules depending on the connectors needed for the job. I was thinking about developing something similar but WAY less complex than the product that they offer.I've looked on the interwebs for something similar, IEEE library, didn't find much that would guide me properly.These are the main questions that I have at the moment:-What would be the best platform when it comes to I/O to use on this project considering that some of our connectors (DIN 41612 series) have 96 pins oneach end? Microcontroller, CPLD or FPGA?-Like on the CAMI research "modular connector boards", I suppose that whenever someone plugs a different module that contains different connectors the software recognizes that, switching the layout displayed on the screen. Does that mean that every different modules needs its own firmware ?Maybe this project is a bit too much for my current knowledge.Thanks.

author: Stray Electron
author_rank: Super Contributor
timestamp: April 03, 2019, 10:37:15 pm
content: I don't know of any literature other than various manufacturer's literature that advocate their own products but it's probably still worth looking at. FWIW I have a couple of Cirrus Systems 1000Rs and Ireallylike them. They make and sell a huge number of interchangeable connector adapters. I think that even the OLD 1000 series can handle hundreds of connections and I've seen but not used big non-portable units that will have many thousands of circuits. Here's a link to a Youtube video of the slightly newer 1100R series.OK I just looked up some of my old Cirrus literature and the 1100R model will test up to 1024 circuits.There used to be a lot of the CS stuff on E-bay but I only found two testers with no adapters when I looked just now. But FWIW the adapters are simple circuit boards with a card edge connector and the connector of choice so it should be easy to make the ones that you need.

author: KG7AMV
author_rank: Frequent Contributor
timestamp: June 29, 2024, 11:48:13 pm
content: I know this is an old topic but i have an older Cami Cableeye M2-Full Serial version inbound I will be doing a teardown of it eventually.

author: Smokey
author_rank: Super Contributor
timestamp: June 29, 2024, 11:57:10 pm
content: Why not a real scanner/switch system? You can pick up Keithley 7001 systems for almost nothing now.
Cable ID - Page 1
Forum section: electronics / beginners

author: jeffjmr
author_rank: Regular Contributor
timestamp: April 04, 2022, 11:35:07 pm
content: I searched long and hard for the name of these connectors and through the lists of cables and connectors from parts houses. Came up empty.Can someone please tell me what I might search for on Newark or Mouser for these in two or four conductors plus the female sockets?Thanks,Jeff

author: Terry Bites
author_rank: Super Contributor
timestamp: April 05, 2022, 12:00:36 pm
content: Do a visual search for "wire to board" connectors on google

author: tooki
author_rank: Super Contributor
timestamp: April 07, 2022, 05:26:28 am
content: It’d help if you actually took close up pictures of the connector (well lit, in focus) of all sides, and at minimum a ruler for scale, but better would be measurements with calipers.

author: jeffjmr
author_rank: Regular Contributor
timestamp: April 07, 2022, 07:00:21 pm
content: Thanks, tooki.In this case, size does not matter. I just need two small cables to allow for a quick disconnect and this type of cable and connector coupled with the female end. Does not need to be board mounted. I just couldn’t seem to find anything on the supply house’s websites to come close to this type of cable and interconnect.The wire to board is certainly the closest.Jeff

author: tooki
author_rank: Super Contributor
timestamp: April 07, 2022, 08:24:20 pm
content: Oh, so just some smallish wire-to-board? There’s tons of things.JST XH (2.5mm pitch) and clones is one of my favorites, as is the Molex KK 254 (2.54mm pitch) and clones (e.g. KF2510). These are readily available from both “reputable” sources like Digi-Key, as well as from aliexpess and eBay, and they’re contacts that aren’t horribly picky when it comes to the crimping tool. (Molex sells a tool for about $120, which is super cheap for a genuine tool.)For wire-to-wire, the clone makers (but not JST itself!) sell wire mount XH connectors, and I know JST has some other series of connectors that have both board- and wire-mount male connectors. A wire-to-wire-only connector I like from JST is the SM series, commonly used for LED strips.
Cable Recommendation / Source - Page 1
Forum section: electronics / beginners

author: wobblycogs
author_rank: Contributor
timestamp: June 08, 2017, 09:58:16 am
content: Hi,I'm putting together some LED lighting for my workshop. I plan on connecting up the individual strips with 2.1mm dc power connectors (these seem to be good for 3A and I only need 2A). I only need to run power about 50cm max and my voltage drop calculations seem to indicate anything more than 0.5mm^2 (20AWG) cable should be good enough for this. I'd like to use 0.75mm^2 (about 18 AWG) cable just to be on the safe side but I can't seem to find any suitable.The cable I'm looking for is the stuff you often find on laptop power supplies. It's almost always 18AWG and has an outer diameter of about 5mm which is exactly what I need for the 2.1mm plugs. I've bought some 0.75mm^2 stranded cable but the insulation is far to thick on it to fit into the plugs.Any idea where I can find this near mythical cable? Even just a name or search terms would be great as searching for "2.1mm power jack cable" doesn't turn up much. I'm in the UK.Cheers

author: wobblycogs
author_rank: Contributor
timestamp: June 08, 2017, 05:01:44 pm
content: Thanks to everyone that read my post, after much searching I think I've finally found some suitable cable.I tried all the big electrical component suppliers, Digikey got the closest but they wanted an arm and a leg considering I only need a few meters of cable.In the end I got back onto eBay, if you search for "DC Power Supply Extension Cable" you'll turn up pre-made cable with 2.1mm jacks on the end. A ten meter cable was about £4 so I'll just cut it down as I need it.Cheers.
Cable removal - Page 1
Forum section: electronics / beginners

author: Hornnumb2
author_rank: Regular Contributor
timestamp: February 12, 2019, 08:39:48 pm
content: How does the lvds cable get removed from this connector? Thanks

author: Doctorandus_P
author_rank: Super Contributor
timestamp: February 12, 2019, 08:44:34 pm
content: The brown, or the thick white is probably a piece of plastic inserted into the socket.Insert a knife / screwdriver / other thin object - behind it and wiggle it alternating left & right in the direction of the Flex cable.Normally these do not come out completely, but only a few mm. Then the Flex should be loose and pop out almost by itself.

author: Yaakov
author_rank: Newbie
timestamp: February 14, 2019, 09:08:51 am
content: Be very gentle opening the latch, they are exceedingly easy to break—along with your heart when you do it.

author: Hornnumb2
author_rank: Regular Contributor
timestamp: February 14, 2019, 03:45:02 pm
content: So the brown part should slide out towards cable. Right?
Cable Shielding - Page 1
Forum section: electronics / beginners

author: logictom
author_rank: Unknown
timestamp: May 01, 2011, 03:52:33 pm
content: What variations of cable shielding exist and when should each be used?I know of and understand twisted pair but that's about itThe reasoning behind the question; I'm looking at building a basic ECG circuit but was wondering whether to purchase a cable for the job, such as the pic below, or build my own.There's three connections for the electrodes but six connections at the other end. From what I understand so far, two cables are used for measurement and the third as a reference but I seem to be hitting a brick wall with the use of the other three connections.If the cable is shielded and the electrode has one connection where does the shielding connect/terminate at the sensor end?

author: DaveW
author_rank: Frequent Contributor
timestamp: May 01, 2011, 04:12:54 pm
content: Well twisted pair isn't really shielding. Shielding is where there is a foil like conductor surrounding the wires. This is normally connected to ground and allows any interference to be conducted away to ground. The most common surrounds all the cables and protects from outside interference. I would guess that what's being done in that ecg lead is that every wire is individually shielded, which has the advantage of preventing cross talk between the signals

author: logictom
author_rank: Unknown
timestamp: May 01, 2011, 04:21:59 pm
content: Quote from: DaveW on May 01, 2011, 04:12:54 pmThanks for the clarification Dave. Sorry yeah I understand its not shielded, I meant to ask about methods for shielding against interference rather than shielded cables specifically, if you get my meaning. Coax would be what I meant to say in the original statement.So in this case the shielding would just be unterminated at the sensor end? Does terminating the shielding effect performance as I always noticed with a TV coax if the signal was strong you could get away without connecting the sheilding

author: DaveW
author_rank: Frequent Contributor
timestamp: May 01, 2011, 05:09:22 pm
content: Twisted pair would be effective if you're looking at a differential signal, but for a single ended signal it won't help. If you're using shielding that's only terminated at one end it won't be quite as effective as terminated at both ends (higher impedance connection), but still reduces interference, may well be enough for this application. As you say using coax should give you the same effect, with some decrease in flexibility