hybridfree/eevblog-posts huggingface dataset:
Tektronix TDS640a vs Rigol DS1054z - Page 1
Forum section: electronics / beginners

author: SirRage
author_rank: Contributor
timestamp: May 30, 2016, 05:32:27 am
content: I have a DS1054z that has the available options installed. I also have a TDS640a that I picked up off of eBay because it was a good price and the initial specs looked quite impressive. 500mhz and 2/gs. Now that I have them both setup, I'm just wondering when I would want to use the 640a over the 1054z. I'm pretty sure think the Rigol beats it out in terms of storage, but I've been having a heck of a time trying to figure out just how much storage this thing has. 2000 points what I think it has, but how that translates to something useful I'm not sure.The TDS640 is in pretty good shape for a scope from the early 90s. The only real issue is that the main fan makes a buzzing sound and the tube shows signs of being burnt in, but it was serviced in 2012 so I imagine it's still in spec.I'm still pretty new to this stuff but I'm having fun with it.

author: JPortici
author_rank: Super Contributor
timestamp: May 30, 2016, 06:17:07 am
content: here you gohttp://w140.com/tekwiki/wiki/TDS640http://www.tek.com/oscilloscope/tds620a-manual/tds620a-tds640a-tds644ayes you should have 2000 points memory on the TDS (aka only what's on screen)it would be interesting to compare the performance during FFT operation (for the joy of rigol bashers) and i suppose you can in general trust more what are you seeing on the screen in terms of vertical accuracy as the fron end is probably of much higher quality and lower noise

author: SirRage
author_rank: Contributor
timestamp: May 30, 2016, 07:54:56 am
content: Cool thanks for the info. It would be kind of fun to do a side by side between the Rigol and TDS.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 30, 2016, 08:56:03 am
content: I'd guess you'll find yourself using the Rigol more. Get out the TDS when you need the bandwidth.Tim

author: Bryan
author_rank: Frequent Contributor
timestamp: May 30, 2016, 10:33:43 am
content: Quote from: T3sl4co1l on May 30, 2016, 08:56:03 amThat's why I kept my 2465B

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 31, 2016, 12:41:50 am
content: Gee, TDS640 isn't much of a step up from a 2465. It's kind of like, why bother?Tim
Tektronix TLA 614 CMOS or NVRAM location  - Page 1
Forum section: electronics / beginners

author: gearheadgeek
author_rank: Newbie
timestamp: March 29, 2024, 07:23:13 am
content: Hello people I will cut straight to the point. I acquired and Tek TLA 614 with a broken screen after determine it can be fixed I got a screen but what I wanted to do is the same thing I did to my TLA 704 is upgrade to a external CMOS battery and a SSD drive and the 704 went off without a hitch no problem but the 614 well I searched the internet for a battery location but could not find one but I did find out about the NVRAM chip. I seen where people replace those but that might be above me. I'm just a old tinker who like to take things apart to see how they work or fix them and give them away. do you think you guys could help me on this it would be much appreciatedthanks in advance

author: m k
author_rank: Super Contributor
timestamp: April 05, 2024, 12:46:53 pm
content: It's not easy, backup first.Last post of a link has a link.https://www.eevblog.com/forum/testgear/new-toy-tek-tla614-logic-analyzer/http://everist.org/NobLog/pics/20160331/20160401_3115.jpg

author: aliarifat794
author_rank: Regular Contributor
timestamp: April 05, 2024, 08:50:09 pm
content: Replacing the NVRAM chip is an option. However, it's not at all easy.
Tektronix2430A start-up waveform display ? - Page 1
Forum section: electronics / beginners

author: lordvader88
author_rank: Frequent Contributor
timestamp: June 14, 2019, 07:05:46 am
content: I have a Tektronix2430A, which is a 1980's DSO. And I have 3 or 4 of the manuals, but I still missed where is says how to do this...when u press PWR it does a self-test, then you have to hit EXIT. Then it just basically uses the last setting u had, and the trace is there, but it's not active, it's like hitting the pause button. So at this point, there scope will sit there forever, with the last settings/functions/etc/ on the screen, and some non-changing trace though.Some of the manuales are on the right side of pagehttp://w140.com/tekwiki/wiki/2430how do I JUST MAKE THE SCOPE START SHOWING WHATS ON THE inputsThe only way I know how to get the CH1/2 input to display real time, is to hit the AUTO button in the SETUP group of buttons, on the front panel. And then it flicks through the different relays and tries to find the most likely signal and hence volt and time div I'd be wanting. And it does it ok sometimes.But surely therer's some other way to start real time display, besides having it press AUTO, and let it search through the ranges, wearing out the relaysRight now, it's on, with all the last settings/functions, displayed on screen, and the wave form just a picture, dead in time, but can be moved up/down and, changed scales, it could also just be in a memory chip.How do I make it start "realtime" display besides hitting auto, surely I'm missing something

author: tautech
author_rank: Super Contributor
timestamp: June 14, 2019, 07:44:43 am
content: Sounds like it's in Normal trigger mode where the trigger level must be within the limits of the waveform to get a live display.Select Auto triggering and you should always have a live waveform to then adjust the trigger to the appropriate level.

author: David Hess
author_rank: Super Contributor
timestamp: June 14, 2019, 04:03:34 pm
content: Quote from: lordvader88 on June 14, 2019, 07:05:46 amI think that means the POST failed for some reason. The common reason is loss of the calibration constants which would be the case if the Dallas NVSRAM batteries have expired.
Tele quarz group filters datasheet - Page 1
Forum section: electronics / beginners

author: ealex
author_rank: Frequent Contributor
timestamp: January 08, 2016, 06:39:19 pm
content: HelloI'm trying to find out data about the following 3 filters and it seems that google is not returning anything useful:If there is no data available, could i use the following procedure to determine input and output impedance, considering that i have a nice RF signal generator available ?1. set the signal generator to 10.7MHz, 0dBm2. use a BCN T connector to split the signal to an oscilloscope and to a filter3. measure the open voltage on the scope ( filter not connected ) - peak to peak for example4. connect the filter and measure the new generator voltage5. change the frequency around the pass band to determine width, etc - i have a AD8307 log detector for that ( i need to calibrate it for 10.7MHz )Determine Rfilter from the generated voltage divider knowing that the generator has 50 ohm output impedance - if RFilter is large ( 2-3k ) it might not be too precise.Is the filter symmetrical ? can i consider the output impedance equal to the input one ?

author: PA0PBZ
author_rank: Super Contributor
timestamp: January 08, 2016, 07:46:31 pm
content: See attachment.07 and 08 look like SSB filters, 24 is AM and/or NFM.

author: ealex
author_rank: Frequent Contributor
timestamp: January 08, 2016, 08:03:25 pm
content: thanks, that's greatthe input termination field: should i read it : equivalent with 500 ohms in parallel with 30pF ? ( i'm new to RF stuff - trying to learn the hard way )

author: Alexdichi
author_rank: Newbie
timestamp: November 28, 2022, 02:10:56 am
content: Hello, where are your find these filters, Yaesu ft180a use same frequency for am, lsb and usb, 10.7015mhz for lsb. Not included, I'm 2 years try to find one here in Paraguay and eBay worldwide... 73..
Telefunken CDP 550A - Page 1
Forum section: electronics / beginners

author: carcanhol
author_rank: Regular Contributor
timestamp: October 01, 2015, 03:57:01 pm
content: Hi, i have this CD player for years and one day it didn't turn on, so i went to investigate and find a burnt resistor.I swapped it with a 1k resistor and the LCD was dim, i swapped the 1k with a .680k one and it was the same dim lcd and no power to the laser head motor.This is a long shot, anyone had the same problem?It looks like it is not getting enough current going in.Buttons work, LCD back light works but a little dim, front equalizer LED's look normal.No movement of the laser head or its lens focusing system or laser light.I even tried with an external power supply with 3,000 volts on the multimeter and no difference.thanks.

author: Cliff Matthews
author_rank: Unknown
timestamp: October 01, 2015, 06:05:38 pm
content: Who is the real mfg.? I see date codes 88 and 90 but TF were bought by Siemens in '85 (I worked my first job at the Ajax AEG avionics plant in '76)That name brings back memories.

author: carcanhol
author_rank: Regular Contributor
timestamp: October 01, 2015, 11:10:17 pm
content: Quote from: Cliff Matthews on October 01, 2015, 06:05:38 pmI know that the player was bought directly in Germany after the 90's and was a set with rechargeable batteries and speakers.

author: rjeberhardt
author_rank: Regular Contributor
timestamp: October 02, 2015, 09:24:40 am
content: Quote from: carcanhol on October 01, 2015, 03:57:01 pmI though at first you meant 3 kV! Then I realise that you're in Europe so "," = "."Russell.

author: carcanhol
author_rank: Regular Contributor
timestamp: October 02, 2015, 05:08:54 pm
content: Quote from: rjeberhardt on October 02, 2015, 09:24:40 amAt first i used a "." then i thought people would see 3kv so changed it. It was 3.000 V on the fluke 79III.

author: babysitter
author_rank: Frequent Contributor
timestamp: October 02, 2015, 06:55:34 pm
content: "Hats gezischt, geknallt, gestunken, wars bestimmt von Telefunken!""AEG - Auspacken - einschalten - Garantiefall"Feel free to use google translator
Telemetry Software for Full Size Solar Car to run on Raspberry PI or Arduino - Page 1
Forum section: electronics / beginners

author: TXcatHerder
author_rank: Newbie
timestamp: June 23, 2025, 06:00:03 pm
content: Hi, All,I'm a Newbie to this, so please bear with me. I'm trying to help out a friend.I am looking for software that will process information for a solar powered racer, such as:Power In/Out of Solar PanelsPower In/Out of BatteryPower In/Out of MotorSpeed of carAccelerationBattery PerformanceAnd any other telemetry data we can get. The plan is to run a Raspberry Pi or Arduino. I'm sure there is something out there that's already been developed, but having a hard time finding something. Could anyone recommend something or be able to code something? It's for a non-profit, Eagle Eye Innovators EEI, Inc., so they don't have a bunch of funds.They also need help with how to wire up the hardware for gathering the data. Not sure what motor controller they are using. Sorry I don't have more details, but I can probably get more info if needed.Thanks for any help!

author: darkspr1te
author_rank: Frequent Contributor
timestamp: June 24, 2025, 09:10:37 am
content: You could use HomeAssistant for this, it's not just software to control a light but it can log from many sensors, including solar mppt units, inverters etc.it's quite easy to setup remote displays (i use esp32's from Elecrow) to display data.darkspr1te

author: TXcatHerder
author_rank: Newbie
timestamp: June 24, 2025, 09:28:13 pm
content: Thanks! I'll pass that along.
Telling to BA6229 to witch way to go - Page 1
Forum section: electronics / beginners

author: Jenna
author_rank: Newbie
timestamp: June 13, 2019, 09:32:54 am
content: Hi thereMy son wants parking garage for his toy cars and of course there have to be a elevator alsoLacking of my c coding skils i dont want use arduino or any similar microcontroller.I think i got an idea how to do this but, topic tells where do i hanged stuck..So how or more specific, i know how to control dc motor go up and down and stop correct level, but what ic chip it should be who tell that old BA6229 controller wich way to go?Some kind of locig ic maybe, but for noobies like me there is so much allkind of chips around there....

author: Dabbot
author_rank: Regular Contributor
timestamp: June 13, 2019, 11:36:15 am
content: How do you want to control the garage door? A single button that activates it?You could rig something up with a pair of D flip-flops (74HC74) and some AND gates (74HC08) which would sequentially give you UP, STOP, DOWN, STOP with each button press.Are you going to place limit switches at either end?

author: Jenna
author_rank: Newbie
timestamp: June 13, 2019, 12:05:14 pm
content: Thans you for ansveringI want control direction of the elevator, i know there is pin 5 and 6 for directions but, example elevator is floor 2 and if i press floor 3 button BA6229 doesnt know direction. So i need some operator (chip) who knows witch floor elevator is and tells BA6229 witch way to go (pin 5 or 6) so its control given signal depending is desired direction up or down.Sorry my english i try to be clear as muchI want make control panel so there is own button for each floor, and i goin to use reed or optical fork switch to tracking floors to stop.i think there is no need for separated limit switch to the ends if every floor have those reed or optical forks

author: Dabbot
author_rank: Regular Contributor
timestamp: June 13, 2019, 12:49:53 pm
content: An elevator with more than two stops requires more complex logic to control. I don't think you will be able to find a single chip which is dedicated to this task, unfortunately.Indeed, these kinds of tasks are what microcontrollers are suited to.
Temp sensor to turn on a circuit - Page 1
Forum section: electronics / beginners

author: shaiss
author_rank: Contributor
timestamp: August 31, 2016, 07:24:25 pm
content: I'm building a 3d printer with dual extruders and two separate fans. Both are run to the same 12v pmw pins on the ramps Arduino board. However, I'd like to wire a "thermal switch" inline with the 2nd fan. This switch would turn on when the thermistor on the 2nd hotend exceeds ~100°c roughly.Questions:Could I use the thermistor that's used on the hotend as the temp sensor?What logic ICS or something else would I need to buy to turn on above a certain temp?How would the min temp be set? Resistors/capacitors?Any rough sketch of a circuit would help and be greatly appreciated.I can attempt to mock something up in eaglecad or another ecad tool if that helps.

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: August 31, 2016, 07:42:47 pm
content: You can use an opamp as a comparator. Use a voltage divider on both inputs. One is fixed a the threshold, the other varies with the thermistor. Should be plenty references on google

author: Signal32
author_rank: Frequent Contributor
timestamp: August 31, 2016, 08:10:14 pm
content: you could use an analog pin on the arduino to read the voltage across the thermister and figure out the temperature in code.Then use another pin on the arduino to turn on/off the fan.No extra logic IC's.As alexanderbrevig suggested, you could also do something like this:

author: Ice-Tea
author_rank: Super Contributor
timestamp: August 31, 2016, 08:20:08 pm
content: Airpax.
Tempco of sense resistor? - Page 1
Forum section: electronics / beginners

author: Faringdon
author_rank: Super Contributor
timestamp: February 09, 2022, 09:05:01 am
content: Hi,Would you say the temp of the CSS2H2512RL500FE 500 milliohm resistor varies less than 1% over -40c to 150c?datasheethttps://www.mouser.co.uk/datasheet/2/54/css2h-2512-1862180.pdfdidnt know what "dR/R25(%)" meant

author: magic
author_rank: Super Contributor
timestamp: February 09, 2022, 10:06:02 am
content: It says 100ppm/°C including copper terminals right on the first page. So <2% worst case drift over your span.R25 is probably resistance at 25°C.

author: Gyro
author_rank: Super Contributor
timestamp: February 09, 2022, 11:33:31 am
content: ... and just in case, 'd' stands for delta, as in 'change in'.
Temperature coefficient of MOS devices - Page 1
Forum section: electronics / beginners

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: June 13, 2017, 01:35:32 pm
content: Not sure if this is going to go too in-depth for the beginner section.I'm reading a paper by Guillermo Serrano and Paul Hasler,A Precision Low-TC Wide-range CMOS Current Reference, IEEE JSSC Vol 43, no 2, Feb 2008.In this paper they use the temperature coefficient of a MOSFET to cancel out the temperature coefficient of a resistor.I understand the temperature coefficient of a poly resistor: As temperature goes up, the amount of electrons in the valence band increases as the bandgap decreases. Hence there are more charge carriers, causing more current to flow at lower voltages. (so a higher conductivity or lower resistance).What I'm confused about is the temperature coefficient of a MOSFET. From what I know, the mosfet actually has a shift in temperature coefficient - at high gate-source voltages it has a positive temperature coeficient, at low gate-source voltages it has a negative temperature coefficient. This negative tempco is what causes thermal runaway to occur.But what physical properties underly this temperature coefficient? What I have been able to come up with is that as temperature rises, the valance band will go up. As a result, more potential is needed to enter inversion. As less electrons are formed in the inversion later (or holes, depending on the substrate doping) there is less to conduct, and thus the current decreases. Is this correct? What about the negative tempco at low Vgs? Can anyone explain?
Temperature controllable soldering iron recommendations - Page 1
Forum section: electronics / beginners

author: Youkai
author_rank: Regular Contributor
timestamp: March 18, 2023, 02:46:06 pm
content: I do projects that include electronics and 3d printing. Recently I saw a video on youtube where A guy was using a temperature controllable soldering iron to weld PLA together. That is something I'll need soon and also I'm going to be starting a fairly large (for me) circuit.I'd like to get a decent version of one and I'm willing to spend a reasonable amount if it's good quality. The one I saw in the video was similar tothis one.Please suggest recommendations for your preferred irons. Also what is a good temperature to solder at?Here's the PLA smoothing/welding video if you are curious:

author: brucehoult
author_rank: Super Contributor
timestamp: March 18, 2023, 09:51:49 pm
content: For light work Pinecil is good. And cool. RISC-V inside and you can re-program it if you want.It's a bit more expensive, but still $40 doesn't break the bank.https://www.amazon.com/PINECIL-Smart-Mini-Portable-Soldering/dp/B096X6SG13The one you pointed to says "thermostatic" not "PID" and it almost certainly wont be PID I think, so it won't hold temperature as well.

author: Gyro
author_rank: Super Contributor
timestamp: March 18, 2023, 09:57:38 pm
content: This thread covers similar low temperature ground...https://www.eevblog.com/forum/manufacture/soldering-irons-that-can-do-low-temperature/
Temperature difference trigger circuit - Page 1
Forum section: electronics / beginners

author: Ron12
author_rank: Newbie
timestamp: August 09, 2020, 08:47:41 am
content: Hi allI would like to make a simple circuit that triggers on temperature difference using two thermisters. So, for example, a fan turns on when the two thermisters (which are in two different locations) see a temperature difference of more than let say 3 degrees. I'm thinking a comparator would be in the mix but I cannot work out how.Any help would be appreciated.

author: Ian.M
author_rank: Super Contributor
timestamp: August 09, 2020, 09:17:57 am
content: Temperature difference in both directions, or one way?(i.e. calling the locations A and B: A 3 degrees hotter or colder than B / A 3 degrees hotter than B)For both cases you'd be looking at a bridge circuit to get a difference in voltage representing the temperature difference, and a comparator, the alternatives decide whether you need a window comparator, or just an ordinary one.Its worth noting that thermistors may not be the best sensors. e.g. thermocouples inherently work by generating a voltage proportional to the temperature difference between two thermocouple junctions. Usually, the 'cold' (reference) junction is in the instrument, and its absolute temperature is measured by a different type of sensor so the absolute temperature of the probe junction can be calculated and displayed, but for differentioal measurement, one could use two probes and eliminate the cold junction compensation circuit. OTOH its a PITA doing long runs of thermocouple wiring as special wire in a different compatible alloy for each side of the probe must be used, and also thermocouple output voltage is very low so requires a lot of amplification.

author: ledtester
author_rank: Super Contributor
timestamp: August 10, 2020, 02:18:28 am
content: From your description of the example application it's going to be more than just a "trigger" circuit -- you'll also want to implement hysteresis control.I would start with temperature sensors that can be read using a microcontroller and implement your fan control in software.More details on the application would help... for instance, how far away are the temperature sensors located from each other?

author: magic
author_rank: Super Contributor
timestamp: August 10, 2020, 06:46:08 am
content: Forget two thermocouples, run one thermocouple from point A to point B and then two identical copper wires from point B to the control circuit. I wonder how far that could be pushed.There are also IC sensors which linearly convert temperature to current, so two of them could be connected to two resistors and the voltages across resistors compared. They aren't perfectly matched and the scheme may need some calibration, but thermistors probably aren't perfect either.

author: Ron12
author_rank: Newbie
timestamp: September 02, 2020, 07:58:28 am
content: Thank you all for your reply's, Thinking about it, what Ledtester said makes sense as they are not linear in their output. looks like I may have to brush up on my Arduino skills.
Temperature Differential Switch - Page 1
Forum section: electronics / beginners

author: BigRich
author_rank: Newbie
timestamp: April 02, 2015, 12:59:00 am
content: Hi,I have an electric smoker that I'd like to modify. The heating element does not maintain the temperature in the cabinet accurately enough for me. There can be as much as a 15 degree swing between the time the element turns off because the set point has been reached and the time the element turns back on to reach the set point again. I am hoping I can replace a component on the motherboard to get the element to kick on sooner. Is this possible?The two orange wires on the left lead to a small wood feeder motor. The two black wires below that lead to the temperature sensor. The red, white, and black wires on the bottom are the voltage lines to the element, the wood heater, and a big wood feeder (in that order). The brown wire on the right is the voltage in from a fuse and the two blue wires above that are neutrals to the wood heater and the power outlet.Thanks.

author: Marco
author_rank: Super Contributor
timestamp: April 02, 2015, 02:52:23 am
content: You can get really cheap digital PID controllers with thermocouple and relay (under 20$ for the lot). Just need to put themin a box.

author: BigRich
author_rank: Newbie
timestamp: April 02, 2015, 09:12:05 pm
content: Thanks for replying. I didn't know I could get them that cheap. I did know I could get them though.I would rather not add additional components. I like the current interface and don't want to change if I can avoid it. This is why I hoped to be able to modify the circuit board.I thought there might be a switch on the board that told the element not to turn back on until it reached a predefined temp difference.I'm guessing since no one else has responded that's not the case or I didn't provide enough information.

author: Marco
author_rank: Super Contributor
timestamp: April 03, 2015, 12:22:15 am
content: There's next to nothing on the board, one of the traces from what I assume is a thermocouple goes straight to the wire bundle of the control panel. I assume that's where the magic happens.
Temperature indicator - Page 1
Forum section: electronics / beginners

author: darinsquared
author_rank: Contributor
timestamp: December 12, 2016, 06:36:26 pm
content: I want to build a circuit like this (fromhttp://www.homemade-circuits.com/2015/01/4-led-temperature-indicator-circuit.html) to measure temperature. I will have three similar circuits (temp sensors) to measure temp at three different levels (TH1, TH2, and TH3). I want to be able to compare each level to another sensor (THref). Would I wire (THref ) in parallel to each sensor as a voltage divider?I calculated my thermistor R=12,000 Ohm at @ 20 Deg C. How do you determine what the R1 value in each sensor? As well, I want a 5-7.5 Deg C difference between each successive LED on each sensor. How do I calculate R7, R8, R9, and R11 values to accomplish this?Would I be better off using a microcontroller and Digital temp probes?

author: kripton2035
author_rank: Super Contributor
timestamp: December 12, 2016, 07:53:13 pm
content: Quote from: darinsquared on December 12, 2016, 06:36:26 pmWell I don't know if it would be better, but it would take less space on the board.

author: darinsquared
author_rank: Contributor
timestamp: December 13, 2016, 03:08:44 pm
content: Would this work? Instead of using a voltage divider, apart from the initial one, I would use diodes (D) to do a 0.7V drop between each comparator lead. I did not put in resistor values but I have them calculated. Coming out of the comparator I go to a resistor and LED to ground.
Temperature of lightbulb tungsten wire - Page 1
Forum section: electronics / beginners

author: Simon123
author_rank: Regular Contributor
timestamp: March 11, 2014, 03:56:36 pm
content: Hello!In school we had to calculate temperatur of lb tungsten from data we collected druing measurments.The formula we were given is R=R20(resistance at 20°c)+R20*a(temperature coeficient)*change in temperature.I rearanged formula like this:?T=(R-R20)/(R20*a)Is this correct?

author: Len
author_rank: Frequent Contributor
timestamp: March 11, 2014, 04:10:40 pm
content: Maybe. Does "?T" mean "change in temperature"?

author: Simon123
author_rank: Regular Contributor
timestamp: March 11, 2014, 04:24:04 pm
content: Yea, sorry i inserted delta symbol and it converted it into this.

author: Len
author_rank: Frequent Contributor
timestamp: March 11, 2014, 04:41:39 pm
content: Quote from: Simon123 on March 11, 2014, 04:24:04 pmYes, it looks correct to me.

author: Simon123
author_rank: Regular Contributor
timestamp: March 11, 2014, 05:02:08 pm
content: Ok, thanks.

author: IanB
author_rank: Super Contributor
timestamp: March 11, 2014, 05:16:39 pm
content: Given:R=R20+R20·a· (T- 20)You can factorize this:R=R20[ 1 +a(T- 20) ]Do you now see a better way to rearrange it?

author: tszaboo
author_rank: Super Contributor
timestamp: March 11, 2014, 10:22:24 pm
content: Hint: It will be around 6000 K to match the color of the sun, unless you tweaked the voltage.You are right, it is getting late.

author: Len
author_rank: Frequent Contributor
timestamp: March 11, 2014, 10:55:25 pm
content: Quote from: NANDBlog on March 11, 2014, 10:22:24 pmThat turns out not to be the case. Tungsten incandescent bulbs are not the same colour as sunlight. You can see this if you turn on a light during the day.

author: ConKbot
author_rank: Super Contributor
timestamp: March 11, 2014, 11:56:47 pm
content: Quote from: Len on March 11, 2014, 10:55:25 pmTraditional incandescent bulbs should be in the 2500-3000K range, and a halogen bulbs run hotter in the 3000K to 4000K range, however thats ideally, assuming the emissions are black-body, which they probably arent exactly, but it should get you in the right ballpark at least.
temperature operation  - Page 1
Forum section: electronics / beginners

author: stoica adrian
author_rank: Contributor
timestamp: March 25, 2016, 09:40:19 pm
content: Hello,I need to understand the temperature operation of this Broadcom BGA,http://www.alibaba.com/product-detail/BROADCOM-Parts-BCM63188VKFEBG-BCM63188-IC-Chip_60356186699.htmlwhat thus ,,Operating Temperature: DESIGN C ,, mean, it is the Commercial: 0 to 70 C range ??https://en.wikipedia.org/wiki/Operating_temperatureI don't find a complete data sheet for this component.Thanks,
Temperature probes PT100 / K type accuracy/calibration - Page 1
Forum section: electronics / beginners

author: cowasaki
author_rank: Frequent Contributor
timestamp: June 18, 2018, 07:09:14 pm
content: I have a couple of cheap Chinese stand alone temperature measuring devices using K types, a K type on my uni-t 60 DMM and I've just bought a 3 wire PT100 which I've wired up as four wires and connected to my Keighley 6100.....The PT100 reads 21 at room temp & 35 against skin (both about right) but 190 against my soldering iron tip which is supposed to be at 290.The two Chinese stand alone are about 5% out from each other.They all read different values. How do people check them? How can you calibrate them?I could try for 100 degrees using the kettle but not many other repeatable temps.

author: Kleinstein
author_rank: Super Contributor
timestamp: June 18, 2018, 07:59:34 pm
content: The soldering iron temperature is not at all an accurate point. Here it really depends on the thermal contact. +-10 K is considered good for a soldering iron.Boiling water is a much better reference point. Meting ice is another. For the 35-45 C range there are rather good medical thermometers.The meting point of pure zinc is another (even official) test point - though not really easy to use.Pt100 sensors often only need a 1 or 2 point check.

author: cowasaki
author_rank: Frequent Contributor
timestamp: June 18, 2018, 09:28:10 pm
content: I'm going to bring the Keithley and the cheapo Chinese K type thermometers into the kitchen tomorrow and check the 100C point with all three. I wanted the PT100 as accurate as possible as I wanted to use that to effectively calibrate some thermometers for home automation etc....
Temperature sensing (12V 8A Solenoid) - Thermistor to TMP36 - Page 1
Forum section: electronics / beginners

author: FearTec
author_rank: Regular Contributor
timestamp: September 23, 2020, 03:24:45 am
content: HelloI am looking to add temperature monitoring to my 12V 8A solenoid (for a project) and am at a crossroad as to what sensor to use?I a thinking Thermistor as it is more presentable when attacking to the solenoid compared to the TMP36's TO-92Thermistor 10K ---------------------------------------------------Store:https://core-electronics.com.au/thermistor-10k.htmlVoltage: ?Accuracy: ?Operating Range: −40°C to +125°CPrice: $1.32 EachDatasheet:https://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Temp/ntcle100.pdfOrTemperature Sensor - TMP36 ---------------------------------------------------Store:https://core-electronics.com.au/temperature-sensor-tmp36.htmlVoltage: 2.7 to 5.5vAccuracy: ±2°C accuracy over temperatureOperating Range: −40°C to +125°CPrice: $2.64 EachDatasheet:https://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Temp/TMP35_36_37.pdf

author: FearTec
author_rank: Regular Contributor
timestamp: September 23, 2020, 03:28:29 am
content: I spotted my bad spelling of Thermistor in my Arduino screenshotApologies, Thanks in advance
Temperature Sensor drawing High Current - Page 1
Forum section: electronics / beginners

author: spider
author_rank: Newbie
timestamp: August 08, 2017, 05:55:46 pm
content: Hello,I have a problem with my electronics project.Parts:"Arduino" NanoBME280 on PCBDatasheet:https://www.bosch-sensortec.com/bst/products/all_products/bme280Here is an image of the PCB because I don't have a schematic.(Pin order: SDO; CSB; SCL; SDA; GND; VCC)The sensor is directly connected to the Arduino via i2c and powered by the Arduino with 5v.5V --> VCCGND --> GNDA5 --> SCLA4 --> SDAI am using this library to control the sensor:https://github.com/adafruit/Adafruit_BME280_LibraryAccording to the datasheet it should draw max. 0.3 µA in sleep mode.Yet I am measuring these currents and voltages:VCC 420 µAGND -40 µASCL -194 µASDA -201 µAReference is the VCC pinGND -4.7 vSCL -3.79 vSDA -3,76 vThe high current flow is particularly bad because it is probably generating a lot of heat within the temperature sensor.I have no idea what is causing the high current flow. To me it looks like that there is too much current flowing over the data lines.

author: floobydust
author_rank: Super Contributor
timestamp: August 08, 2017, 07:18:08 pm
content: BME280 is not a 5V partIt runs off 1.7-3.6VDC so you probably damaged it.VCC should connect to +3.3V on the Arduino PCB.

author: spider
author_rank: Newbie
timestamp: August 08, 2017, 07:32:07 pm
content: Changed it back to 3.3v. Sensor ist still working fine.At 3.3v I can break the GND connection and it is still working.I'll measure current and voltages tomorrow.

author: floobydust
author_rank: Super Contributor
timestamp: August 08, 2017, 09:39:10 pm
content: It looks like your PCB does not have a I2C level-translator (3.3-5V), instead only using 4k7 resistors. Most BME280 boards have IC/MOSFETS for this.So -ve currents will flow when 5V TX happens feeding into 3.3V part with 4k7.The sensor has many modes and you can change the sample rate, filtering to lower current drain.I found the Adafruit BME280 Arduino library gave high temperature readings. Several degrees C higher than should be readIt might have a bug reading the calibration table for temperature. Tried another library and it was better. Bosch's C code is heavy on floating point for an Arduino.Let me know how your temperature readings are.The BME280 is sensitive to light, no bright light while reading it.

author: spider
author_rank: Newbie
timestamp: August 09, 2017, 04:19:32 pm
content: I am sampling the sensor quite slow at 0.5 Hz and 16x oversampling for temperature and pressure.It is reading 0.5°C higher than my ±0.5°C reference thermometer at 5v. On the other hand it is reading ±0.1°C at 3v compared to the reference thermometer.At 3v I am now measuring these currents in sleep mode.VCC -40 µAGND 0 µASCL 20 µASDA 20 µA-40 µA and 0 µA looks weird to me. While the sensor is reading the VCC current turns positive and the data lines negative. GND stays zero.
Temperature sensor for induction motor case and stray magnetic fields - Page 1
Forum section: electronics / beginners

author: e100
author_rank: Frequent Contributor
timestamp: January 01, 2017, 07:09:09 am
content: Are temperature sensors such as thermistors, RTDs or the DS18B20 affected by the stray magnetic field from an induction motor when mounted on the exterior aluminium heatsink?I only need 1 degree C resolution. Can I just use them like normal, or do I need to synchronise the readings in time with the magnetic field to get consistent values?

author: SeanB
author_rank: Super Contributor
timestamp: January 01, 2017, 07:30:03 am
content: No, you just need to ensure that the wiring is twisted and no large open loops to induce AC voltage into it. Shielded twisted pair cable is easiest to use, though almost all of the motor protection sensors are just twisted pair high temperature wire inside the motor itself, and you generally in any case want to do averaging over a few readings as well, reduces noise in all cases.

author: Richard Head
author_rank: Frequent Contributor
timestamp: January 01, 2017, 02:08:54 pm
content: Also, ensure that there is minimal capacitive coupling between the sensor and the motor frame. If they share the same ground it shouldn't be a problem but if the circuitry is floating wrt to AC earth then it may be a problem. Maybe a good idea to add some hysteresis to the switching point so when the motor overtemps it doesn't re-start 15 sec later.
Tempreature sensing fan - ideas? - Page 1
Forum section: electronics / beginners

author: LektroiD
author_rank: Frequent Contributor
timestamp: May 01, 2015, 02:21:56 pm
content: I have two Mackie 2U rack mount power supplies for the mixing desk in my studio, and the fans inside are driving me insane.I have reduced the speed of the fans by using a few diodes in series, the voltage drop of the diodes has been enough to quieten them, but they really only need to come on when the heatsinks are warm. What is the easiest (lowest component count), way of making a temperature sensing fan?I was thinking of using a flatflex style CPU temperature sensor affixed to the heatsink with kapton tape in series with the positive feed to the fan. Would this work, or can someone think of a better idea?

author: kripton2035
author_rank: Super Contributor
timestamp: May 01, 2015, 02:33:16 pm
content: something like this :http://www.ebay.com/itm/1pcs-Temperature-Controlled-Switch-Thermostat-80-C-N-C-KSD301-Normal-Close-10A-/111354130613?pt=LH_DefaultDomain_0&hash=item19ed3930b5

author: mushroom
author_rank: Regular Contributor
timestamp: May 01, 2015, 02:37:39 pm
content: You will find many example of such a controller (temp sensor + PWM or linear) with Google. Many have been built since late '90s. Google with "temperature based fan control" ; Google Images will shows you a huge amount of solutions. In the old times, it was analogic control. Now, it is very easy to build around an Arduino Pro Mini or Nano.https://www.google.com/search?q=temperature+based+fan+control&source=lnms&tbm=isch&sa=X&ei=So9DVeSZApWwaeTsgNAK&ved=0CAcQ_AUoAQ&biw=1242&bih=742There are also specialized ICs (used on mobos and graphics cards)

author: dom0
author_rank: Super Contributor
timestamp: May 01, 2015, 03:14:16 pm
content: Lowest part count: Si-diode (1N4148) + power transistor + resistor. Select the diode such that it's Vf is slightly below the transistors Vbe. Put it in parallel with the BE junction. Supply current to the base node through the resistor. If the transistor gets warm it's Vbe will drop, leading to it conducting.Yes. This even works.A more serious approach: Use an emitter follower fed by a voltage divider with a thermistor/NTC in the upper leg. The thermistor gets hot beyond it's thermistor temperature and it goes low-resistance rather quickly, leading to the fans spinning up.(Actually, still just three parts. But I have a few hundred times more diodes than thermistors in my stock, so OTOH...)

author: daybyter
author_rank: Frequent Contributor
timestamp: May 01, 2015, 04:08:48 pm
content: http://www.dx.com/de/p/my-428-ksd9700-thermal-sensor-temperature-control-switch-for-fan-black-golden-246147#.VUOkxcu-eYo
TENMA 72-8225 40Mhz Oscilloscpe DAT file - Page 1
Forum section: electronics / beginners

author: simon christo
author_rank: Regular Contributor
timestamp: April 29, 2019, 08:08:14 am
content: Hi there! This is my first post. I've got a Tenma 40Mhz Oscilloscope and it has a feature that can store100 seconds of a particular channel on a USB stick.The waveform stored is a DAT file, and I'm havingtroubles displaying it on a PC computer.I couldn't store it as an attachment, as the limitations on thissite doesn't allow it.It has no commas, so it's not a CSV file, it just 8 bit hex, one after the other.Where would I get a DAT reader to display this waveform.Thanks Simon.

author: connectTek
author_rank: Regular Contributor
timestamp: April 29, 2019, 08:43:03 am
content: https://www.element14.com/community/thread/65498/l/tenma-waveform-file-format?displayFullThread=trueSent from my TA-1012 using Tapatalk

author: connectTek
author_rank: Regular Contributor
timestamp: April 29, 2019, 08:54:13 am
content: https://www.manualslib.com/products/Uni-T-Utd2042c-8824268.htmlThe Tenma is the same as UTD2042CRead the manual.It states you can only read data file on scope.But you should be able to save as bmp format.Sent from my TA-1012 using Tapatalk
Tenma DC Power Supply 72-705 - Page 1
Forum section: electronics / beginners

author: Dragon-foot
author_rank: Newbie
timestamp: April 11, 2019, 01:38:04 pm
content: Good Morning All,You guess it. I'm a newbie. I'm trying to get any info on the above power supply. I have contacted Tenma and was told that its to old and that they do not have any info. I have google it.Searched any sites that deals with older manuals, no luck your site is the only site that even has the model number listed. I tried to reach out to the person that posted it. But was unableto email him. I saw that he was a fellow ham and looked up his call sign, but no email address listed.Thanks

author: Andy Watson
author_rank: Super Contributor
timestamp: April 11, 2019, 02:24:05 pm
content: Can you post some photos? Tenma are usually re-badged designs - you might have more luck if you can identify the original manufacturer.

author: mikerj
author_rank: Super Contributor
timestamp: April 11, 2019, 04:20:38 pm
content: Googling images of that model it looks very much like the XG95D that Maplin in the UK used to sell under their "Precision Gold" brand.If so it's based on the trusty old 723 regulator IC, so about as basic as you can get for a regulated supply. There is a thread on thevintage-radiosforum which includes a schematic that someone drew on one channel.

author: Andy Watson
author_rank: Super Contributor
timestamp: April 15, 2019, 05:32:38 pm
content: Quote from: mikerj on April 11, 2019, 04:20:38 pmAnd the Lodestar PS 303D.
TeraTerm Top of Page question, - Page 1
Forum section: electronics / beginners

author: CaptDon
author_rank: Super Contributor
timestamp: June 27, 2023, 09:12:11 pm
content: I have about 10 lines of data that spits out every few seconds. So it scrolls down the screen forcing the old data upward on the screen. I would like the new data to simply over-write the old data so that if there were no change between old and new data the screen wouldn't change except for maybe the cursor running through the lines. I found the ESCAPE C works as a 'clear screen' function but that isn't what I need. I need to reset the cursor to the top left corner of the screen while leaving the old data in place to be over-written with new data. I have tried some of the standard STX start of text, FF form feed but none do what I need. Perhaps TeraTerm lacks this function? Any ideas? Since I am only writing perhaps 10 lines of data/text if I could reset the cursor position I would never scroll to the bottom of the screen. I suppose a CR followed by a bunch of 'Cursor up one line' commands would work but that seems wasteful. Thanks!!

author: ataradov
author_rank: Super Contributor
timestamp: June 27, 2023, 09:19:47 pm
content: TeraTerm supports standard VT100 terminal escape sequences. You have full control over the cursor positioning using them.Here is a good referencehttps://www2.ccs.neu.edu/research/gpc/VonaUtils/vona/terminal/vtansi.htmSee cursor control sequences for cursor movement without erase.

author: CaptDon
author_rank: Super Contributor
timestamp: June 28, 2023, 12:19:47 am
content: ESC [ H works perfect!!! Thanks!! We used to see this type of display years ago where the lines of data would show current updated data and the only thing that was kind of annoying was the cursor dancing through every few seconds. But at least text wasn't scrolling off the screen faster than could be observed by a human. I can update the machine's output data string to include the 'Cursor Home' sequence prior to spewing out the current data strings. Thanks again!!

author: HwAoRrDk
author_rank: Super Contributor
timestamp: June 28, 2023, 12:47:49 am
content: One method you can also use if you have a significant amount of static, non-changing text (i.e. labels/captions), is to use cursor positioning codes to only update (by overwriting) the changing values. That way you only have to send the static text once, and not on every update. Although, one caveat is that you have to be using padded fixed-length values, otherwise you'll end up with a mixture of digits from old and new values
Terminal Block where all terminals connect? - Page 1
Forum section: electronics / beginners

author: stevedc
author_rank: Contributor
timestamp: June 17, 2016, 03:28:35 pm
content: Looking for help with something...I'm seeking something like a screw terminal block but instead of the terminals insulated from each other, they are actually all connected. But I can't seem to find it online and don't know what it's called.(I want to connect a bunch of wires in an organized way, without soldering or making a big pigtail.)Appreciate any ideas. Thanks.

author: xrunner
author_rank: Super Contributor
timestamp: June 17, 2016, 03:33:53 pm
content: Quote from: stevedc on June 17, 2016, 03:28:35 pmLike this? They also sell jumpers that you have to use to make several connect together.

author: SeanB
author_rank: Super Contributor
timestamp: June 17, 2016, 03:40:20 pm
content: If your use will live with push in fittings then Wago connectors, otherwise if you have a DIN rail available ( either symmetrical top hat or asymmetric) then use DIN rail connector blocks and a commoning kit that joins them together neatly with a nice heavy brass bar.

author: stevedc
author_rank: Contributor
timestamp: June 17, 2016, 03:53:05 pm
content: Ok, great - thanks for the replies. "Terminal block jumpers" seem to fit the bill.I was wondering if there was an item that had the jumpers already built into it. (If not, adding the jumpers is easy enough!)

author: stevedc
author_rank: Contributor
timestamp: June 17, 2016, 04:12:27 pm
content: I guess what I'm really after is a "bus bar" that could be used in low-voltage applications (but something that's not too expensive). Something like this - but this is $13 which is nuts.
Terminate unused multiplexed I/O's in STM8S001J3 - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: December 12, 2019, 02:12:22 pm
content: 1. How to terminate unused multiplexed I/O's terminations in STM8S001J3.E.g Pin 8 of it is multiplexed to 4 I/o's : PD5,PD3,PD1,PC6 . I am using PC6 only. How to terminate rest of 3 I/O's in this?2. If I keep rest of three as output 0, then interfere with high low operation of PC6, it wont let PC6 to turn high on.3. is it necessary to terminate these unused multiplexed? If yes how?I suspect in high current consumption than datasheet.
Tesla coil varnish? - Page 1
Forum section: electronics / beginners

author: kalel
author_rank: Frequent Contributor
timestamp: October 15, 2017, 09:30:00 am
content: I believe I saw someone on YouTube, possibly ElectroBOOM (but I can't find the exact video now), mentioned that for high voltage coils, his Tesla coil experiments, some additional varnish should be added with a brush to the coil winding (after it has been wound), to increase insulation and prevent the coil from "shorting" (These are not at all the exact words, I'm not even sure if that is from his videos).These things are useful to keep in mind for future reference, and I'm wondering what kind of varnish can be used, and what are some of the cheapest solutions.

author: lapm
author_rank: Frequent Contributor
timestamp: October 15, 2017, 09:32:59 am
content: geekgroup recently made few big coils and they coated them with epoxy, just had to keep coils rolling while it hardened to have smooth surface. Chris Bowden made videos about it as well..

author: Vtile
author_rank: Super Contributor
timestamp: October 15, 2017, 11:37:14 am
content: To increase the insulation properties between coil turns as I would assume that in a big Teslacoils the turn potential (the voltage difference per coil loop) will be rather high.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 15, 2017, 06:15:43 pm
content: Hardware store varnish is fine. It's probably on the lossy side, but you're probably not running at a high enough frequency for that to even matter.It's more about holding turns in place, than providing insulation. If you're cranking a lot of power, it may help to use conventional insulated wire (which will also have a higher pitch, giving lower losses).Tim