hybridfree/eevblog-posts huggingface dataset:
Cccv charging method for lithium in simscape simulink  - Page 1
Forum section: electronics / projects

author: Albatool
author_rank: Newbie
timestamp: July 31, 2021, 11:11:20 am
content: I have done the ctcv charging of one of the research paper and now I want to know the differences in simulationIf cccv needs pid controllerAnd I want to simulate cccv charger algorithm and other things that can help me.
CCD image sensor interfacing / messing with CCD sensor - Page 1
Forum section: electronics / projects

author: Bendba
author_rank: Regular Contributor
timestamp: October 30, 2016, 03:56:25 pm
content: Hi,I was tearing apart a couple of devices from my scrap bin today. And a came across a dead Pentax K200D (body damaged and motherboard dead)But the whole optic assembly seems to be good. So I though that'd be a good subject for learning and experimenting.The mechanic is clear to me (I took a couple of slr cameras apart and played with them, a couple of AA batteries to run the motor and latch the few electromagnets, no rocket science there) but the digital sensor part isn't.I've read about CCD image sensors but I can't seem to find much about the image acquisition itself. I'm talking about pulling the data out of the sensor and storing them in a memory.This particular sensor is a 10.7 megapixels colour CCD (3872 x 2592, supposedly 10.2 megapixels effective. which when I was at school only gave me 10.04 mega but whatever)I wouldn't mind, just for the sake of it, being able to expose the sensor (easy part, one I understand how to clear the sensor) and extract the image to say an sd card, just a RAW file, not a processed image.I guess the first questions to answer to understand how possible (or not this is) are the following:- How long does a sensor retain the image? (Can I take say 4 seconds to read it out? I'm guessing it only would produce more noise while waiting seen you can make a 30s exposure)- Does a sensor have a minimum clock speed for scanning? (If I was just doing a read/dump cycle with a 40 MHz clocked processor, would I be anywhere near something feasible?- Should I wait till I find a much smaller sensor to fiddle with? 10 megapixels in colour, assuming it uses a RGGB filter, that's 40 megabytes of data to process isn't it? Or can I do something like read one pixel, skip two, read one, skip two,... skip two lines, read one,...?Before I shoot out a heap me questions, is there a good reference material about CCD image acquisition? Or do I just throw the rest of my questions at you?Thanks?
CCD line sensor outputs clean square wave - Page 1
Forum section: electronics / projects

author: m98
author_rank: Frequent Contributor
timestamp: November 30, 2022, 01:34:26 am
content: Hi,I'm trying to read out an EPC901 CCD line sensor, applying the proper read clock after a shutter pulse when the data ready pin goes high.But on the video output pin, I get a perfect square wave (note the probe ground is attached over a long lead)Schematics:Any ideas on what could cause the sensor to generate this output?Thanks

author: m98
author_rank: Frequent Contributor
timestamp: December 01, 2022, 04:28:39 am
content: Ok, so I already found out why the sensor didn't respond to light, clearing the pixel buffer before capturing an image really isn't optional, and I accidentally disabled the GPIO pin responsible for that signal. Now every second pixel does seem to respond correctly, but the output still goes low every time in between. Also saw that I accidentally have 2 pixel binning enabled over the configuration inputs, so I explicitly disabled it via I2C. But the datasheet even states that binning reduces the amount of neccessary read clock pulses by the binning factor, so when factor 1 requires 1024 + 3 clock cycles for a full readout, factor 2 only requires 512 + 3, with the data ready signal going low after a full readout. It did only go low after the full 1027 cycles.... Turns out the datasheet is probably wrong, or incomplete. Forgot to set the configuration enable bit, so now that the I2C configuration actually has an effect, and pixel binning is disabled, the issue is gone and the sensor works as expected.At least I've now found a method to verify the video amp bandwidth without using a shadow mask on the sensor
CCFL Driver Data - Page 1
Forum section: electronics / projects

author: Cyberdragon
author_rank: Super Contributor
timestamp: January 05, 2015, 10:49:11 pm
content: I want to make a lamp out of 2 CCFLs I found in the monitor of a broken computer I had. I know the pinout of the driver (on board) but I don't know the voltage. I ran it to about 10v and it didn't turn on but I'm afraid to go any higher in case it's another reason it's not turning on. (I tried touching the on/off pin to both positive and negative)It's a Darfon 4H+V1641

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 06, 2015, 08:34:39 am
content: Do you have enough of the power supply that you can trace backwards and estimate supply voltage?Tim

author: Cyberdragon
author_rank: Super Contributor
timestamp: January 06, 2015, 07:52:46 pm
content: It came out of a cheap integrated computer with everything in the monitor. I'm pretty sure it ran on a single 18V power supply with local regulation. I've run it all the way to 18v and it's drawn no current (or less then 10mA). I've already checked the on board fuse.I'll see if I can get data for the chips.MP10091ESNikos P2804BV6 (x2)

author: SeanB
author_rank: Super Contributor
timestamp: January 06, 2015, 08:22:54 pm
content: It will have an enable input that will likely need to be pulled to 5V to turn it on.

author: Cyberdragon
author_rank: Super Contributor
timestamp: January 07, 2015, 03:29:02 am
content: Um...oops...I put the on/off pin to the power bus (first thing I tried).Nothing happened though, so nothing new blew out that wouldn't already be dead. If the chip had blown I would have expected it to go short and blow the fuse. It might have an over-volt diode on the input, so I could still try 5V and see if it starts.
CCFL driver - Page 1
Forum section: electronics / projects

author: tarasv
author_rank: Newbie
timestamp: November 06, 2023, 10:16:55 pm
content: I have brick dead Asus G1S notebook lying on my shelf for years. Recently looked for something good inside. As I remember LCD backlight was workable. So may be used for picture frame with backlight etc. Problem is CCFL driver. IC is mp1010bef but driver schematics definitely not from datasheet. Driver has 10 wires connector instead of 5 wires by datasheet and some extra components. Googled for interface spec but no success. I found doubled ground wire in connector but rest isn't clear. Maybe someone knows where to look for the interface spec or have it? btw p/n is 08g26ab10107
CCFL inverter as basis for easy low-current 500V DC supply? - Page 1
Forum section: electronics / projects

author: mmagin
author_rank: Frequent Contributor
timestamp: April 30, 2016, 04:59:38 pm
content: Would there be any problems with using something like a TDK CXA-L10L(900V AC open circuit), bridge rectifier (1.5kv rated diodes), high voltage film capacitor, and a resistor+string of zeners shunt regulator to achieve regulated 500 V DC at a couple milliamps?I mostly know it's not their usual load, so I'm wondering if that would present any problems.

author: mathias
author_rank: Regular Contributor
timestamp: May 01, 2016, 04:37:15 pm
content: Nope, should work like a charm. I've built one to power up my PMT at 1.6kV at 250uA (about). Not a problem there.

author: wraper
author_rank: Unknown
timestamp: May 01, 2016, 07:00:44 pm
content: Sounds like very inefficient and awkward way to do this.

author: Marco
author_rank: Super Contributor
timestamp: May 01, 2016, 07:07:06 pm
content: Quote from: mmagin on April 30, 2016, 04:59:38 pmYou can use an adjustable linear regulator to modulate the input voltage to the inverter, with the feedback provided by a divider from the high voltage output. Dodgy hack, but quite common.

author: mmagin
author_rank: Frequent Contributor
timestamp: May 01, 2016, 07:37:58 pm
content: Quote from: evb149 on May 01, 2016, 06:55:54 pmThanks for the idea. But I'm less concerned about efficiency than having a fairly clean output.Very good point about the diodes though.

author: Zero999
author_rank: Super Contributor
timestamp: May 02, 2016, 03:06:01 pm
content: The TL431 will give fairly good regulation but is only rated to 36V but when used with a cascode it can work up to much higher voltages.

author: mmagin
author_rank: Frequent Contributor
timestamp: May 02, 2016, 05:46:47 pm
content: When reading evb149's post, I was imagining more something like a 200:1 resistive voltage divider to bring the 500 volts down to 2.5 volts and using the TL431 as a comparator + voltage reference, which would then drive the LED in an optocoupler.
CCFL inverter output is AC or DC?  - Page 1
Forum section: electronics / projects

author: seanspotatobusiness
author_rank: Regular Contributor
timestamp: December 19, 2017, 02:43:56 am
content: I've read that the reason one wire of a CCFL inverter is thin and the other is thick is because the thicker one has more insulation to carry the high voltage whilst the other is grounded. This means that the output is DC, right? However, I've also read that the output is AC.Sent from my SM-G900F using Tapatalk

author: ovnr
author_rank: Frequent Contributor
timestamp: December 19, 2017, 02:54:18 am
content: The output is AC - CCFL tubes would not appreciate having DC applied for a substantial amount of time.And yes, the thin wire is grounded. The thicker wire carries the AC voltage, going from +500v to -500v (or whatever voltage the inverter runs at) relative to ground.Even household mains works the same way in most civilized countries, where one lead is neutral - and bonded to ground somewhere upstream - while the other is swinging between a positive and negative voltage.

author: seanspotatobusiness
author_rank: Regular Contributor
timestamp: December 19, 2017, 10:23:19 am
content: Thanks very much!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 19, 2017, 10:42:08 am
content: CCFLs use AC, typically 20-30KHz, with a very high voltage ( 1-2kv) for initial striking then run at a few hundred once struck. One side is generally grounded

author: Zero999
author_rank: Super Contributor
timestamp: December 19, 2017, 11:00:13 am
content: Quote from: ovnr on December 19, 2017, 02:54:18 amYes, except with the mains, both conductors must have the same level of insulation, as the neutral can rise to the full mains voltage, if there's a break in the circuit.

author: ovnr
author_rank: Frequent Contributor
timestamp: December 19, 2017, 12:20:52 pm
content: Quote from: Hero999 on December 19, 2017, 11:00:13 amVery true. You should never count on mains neutral to be close to ground, even though it's supposed to be.

author: james_s
author_rank: Super Contributor
timestamp: December 19, 2017, 11:46:42 pm
content: That and there's no reason for either mains wire to have unusually thick insulation, and there are situations where the wire intended to be neutral can be used as a live conductor. For example switch drops where power comes directly into the light fixture box and a separate cable goes over to the switch. In these cases you're supposed to use tape to mark the white wire as live. It wouldn't make sense to make wire with asymmetrical insulation even if it were allowed. It's not like a CCFL where one wire carries high enough voltage that it needs special relatively expensive insulation.
CCFL LCD monitor is not very good as a lamp - Page 1
Forum section: electronics / projects

author: lordvader88
author_rank: Frequent Contributor
timestamp: December 12, 2018, 05:16:39 am
content: I scrapped a 32" TV, and it has a nice PSU and some chips I can play with, and I manged to figure out how to get the CCFL working off the PSU alone, but sadly it's not even worth it as a wall lamp in my room I don't think. I don't need a lightbox ATM, and have a much smaller 19" I could scrap to use for that.What else could I use the CCFL for? I hate to toss it. I'll keep the HV inverter tho either way

author: james_s
author_rank: Super Contributor
timestamp: December 13, 2018, 06:39:53 pm
content: Art? Those thin bare tubes look pretty cool. Maybe a sort of miniature architectural neon tube?

author: Miyuki
author_rank: Frequent Contributor
timestamp: December 13, 2018, 09:58:56 pm
content: CCFL are not very efficient by today standards compared to LED technology and have this complex HV power supply

author: james_s
author_rank: Super Contributor
timestamp: December 13, 2018, 10:32:36 pm
content: I wouldn't call the power supply complex, certainly no more so than a decent LED driver. They are not particularly efficient but they do look cool.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 14, 2018, 02:24:32 pm
content: The panel blocks something like 85% of the light, remove it and it will be much brighter. Assuming it's not a super cheap bargain basement TV and the tubes aren't worn out, the light quality will be very good as they're meant for display use.

author: james_s
author_rank: Super Contributor
timestamp: December 14, 2018, 05:20:26 pm
content: I used some monitor backlight tubes as an accent light for a while some time back, the light was ok quality but the color was weird. Very high color temperature but gave everything an odd sort of pinkish hue, still it was an interesting light source.
CCIR656 Parallel Digital Video & SDI To HDMI Conversion - Page 1
Forum section: electronics / projects

author: dexters_lab
author_rank: Unknown
timestamp: December 19, 2016, 02:54:50 pm
content: I am looking at the possibility of getting some digital video out of my quantel paintbox.All the later paintboxes have either YUV component analog and CCIR656 parallel digital video or SDI outputs so converting the digital video to HDMI is probably the best thing to allow capture of the video for importing to a PC.I'm not concerned with inputting digital video to the paintbox though.There do seem to be commercial products out there to do this task as well as a few dedicated ICs for the conversion so i was wondering if there are homebrew or open source projects i could look at, or any other options i have not thought of?thanks!
CCP PWM mode in PIC (S.O.S) - Page 1
Forum section: electronics / projects

author: danielks
author_rank: Contributor
timestamp: August 31, 2011, 10:35:45 am
content: Is it possible to configure CCPR1L with decimal point duty cycle ? such as 0.5% DC. Can anyone help me ?

author: ElektroQuark
author_rank: Unknown
timestamp: August 31, 2011, 10:39:25 am
content: Use an 1% DC but half the frequency.

author: danielks
author_rank: Contributor
timestamp: August 31, 2011, 10:57:34 am
content: Sorry I dont get what you mean. Let say I need to control a Servo. The frequency will be around 50Hz any lower frequency will cause the servo to malfunction.
CD Capacitive Discharger for Stud Weld - Looking for more information - Page 1
Forum section: electronics / projects

author: rvalente
author_rank: Frequent Contributor
timestamp: January 12, 2017, 07:27:17 pm
content: Hello Mates,I wish I could spent 5 grand on a nice capacitive discharge stud weld, well I can't thus I must made one..After some googling I've found some information on the Soyer BMS-8N, it uses a 3 x 22mF (mili) at 200V to weld studs from M3 to M8 (enough for me), all this power runs through a beefy SCR. (page 14)I was looking for pulse electrolity capacitors, which capacitor do you guys think they use?http://soyer.de/gb/assets/downloads/w7e02030d202800027c07c10ac32b033/w7e051f0f3713001b9dc4553b082a4de/Bedienungsanleitung%20BMS-8N_BMS-8NV_01.08.2015_englisch.pdfAny papers on this subject?

author: Marco
author_rank: Super Contributor
timestamp: January 12, 2017, 08:02:46 pm
content: Since you are trying to undercut Chinese machines well below 1K$ I'd say that beggars can't be choosers, the cheapest surplus 200V+ electrolytics you can find and beg they don't blow up.
CD4051 Analog Multiplexer Actual Voltage Range - Page 1
Forum section: electronics / projects

author: pacmann
author_rank: Contributor
timestamp: February 20, 2022, 01:10:55 pm
content: I want to use CD4051 to expand how many analog signals to read with a single A2D pin on the microcontroller.Voltage range from the analog inputs to the 4051 are 0-3.3v. If VDD connects to 3.3v and VEE and VSS connects to Gnd on the 4051, will it be able to output the full 0-3.3v range on the Common pin or is there a dead zone below or above a voltage that will be clipped? Is there a parameter in the data sheet to clarify this?Thx

author: Kleinstein
author_rank: Super Contributor
timestamp: February 20, 2022, 01:41:15 pm
content: The CD4051 will work all the way the the supply range and even a little (e.g. 300 mV) above and below. Than the internal diode would engage.This is normal behavior with modern CMOS switches. The data-sheets may show anlog signal range, but on what details are in the DS can vary between manufacturers and DS version.With only 3.3. V the CD4051 is relatively high resistance. 74HC4051 may be the better choise with low voltage.

author: pacmann
author_rank: Contributor
timestamp: February 21, 2022, 11:39:15 am
content: Thanks for the details! 74HC4051 is a good suggestion!I have some CD4051 around and wanted to use them up before buying new. Do you think since the "output" of CD4051 connects to the A2D pin that a 1000 ohm series resistance will attenuate the signal? Depends on A2D pin impedance I guess.Cheers!

author: Kleinstein
author_rank: Super Contributor
timestamp: February 21, 2022, 11:52:02 am
content: It denpends on the ADC, wether it can accept some 1-3 kOhms of series resistance. At least what I have found the specs are for 5 /10/15 V only with the CD4051, though it is supposed to work from 3 V on.

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2022, 12:06:19 pm
content: Do you have a higher power supply voltage available? If you can bump the supply voltage to the CD4051 up to 4.5V, the resistance will drop. I wouldn't recommend going any higher, otherwise it won't work properly, with 3.3V logic. If you have a 5V supply, use a diode and a pull-down resistor to create 4.4V.

author: Bassman59
author_rank: Super Contributor
timestamp: February 21, 2022, 03:09:35 pm
content: Quote from: Kleinstein on February 21, 2022, 11:52:02 amBuffering the switch output with an op-amp will help with driving the ADC input.
CD4066 with lower control voltage - Page 1
Forum section: electronics / projects

author: old gregg
author_rank: Regular Contributor
timestamp: July 12, 2016, 04:34:12 pm
content: does it exist a CD4066 equivalent with a lower voltage to control the switching ?Let's say I'm powering the chip from a 9V supply rail and I want to control it with a 5V/0V digital logic. I'd like it in the same price range. I know it isn't christmas yet but still, maybe...thanks

author: bktemp
author_rank: Super Contributor
timestamp: July 12, 2016, 04:40:32 pm
content: The same price range is probably impossible. The easiest solution is adding a level shifter using a transistor + pullup.Analog Devices has many multiplexers with buildin level shifters:http://www.analog.com/en/products/switches-multiplexers/analog-switches-multiplexers/single-supply-2v-to-16v.html

author: old gregg
author_rank: Regular Contributor
timestamp: July 12, 2016, 04:45:08 pm
content: I'd like to avoid adding components to the design. There's also the idea to keep the signal under the CD4066 voltage and adding gain after it.

author: Kleinstein
author_rank: Super Contributor
timestamp: July 12, 2016, 05:13:35 pm
content: For a very limited range, there is the 74HCT4066: can be powered with 5 V and controlled from a 0/3 V signal.A 4053 might help in a limited range, powered from e.g. +5 V and -4 V (thus 9 V total) and controlled by 0/5 V. But this is a different switch configuration.

author: bktemp
author_rank: Super Contributor
timestamp: July 12, 2016, 05:57:14 pm
content: Both 4051/4052/4053 and 4316 support a higher total supply voltage, but only when used with a negative supply voltage.Vdd is still limited to +6V for the HC version, so applying +9V betweend Vdd and GND is not possible and applying +9V between Vdd and Vee and using a GND referenced 0V/5V control signal does not work!

author: old gregg
author_rank: Regular Contributor
timestamp: July 13, 2016, 11:56:34 am
content: thanks for the answers guys !Yes the (ideal) requirements is to power up the CD4066 with 9V (to allow greater signals in) but the control voltage for the switching must be 5V or less. Despite my research I haven't find anything significant. Looks like a lost cause.I've had great success with using a 7.5V/-7.5V (for bipolar application).
CE: ETSI  RF European   forums - Page 1
Forum section: electronics / projects

author: JoeyG
author_rank: Regular Contributor
timestamp: March 06, 2020, 04:15:34 am
content: Hi ,I am in Australia.I am looking for any forums discussion European RED RF regulation and certification.Id like to ask some basic questions before asking a test house.particualar views onhttps://www.etsi.org/deliver/etsi_eg/203300_203399/203367/01.01.01_60/eg_203367v010101p.pdfThanks in Advance - Joe from Australia

author: bjbb
author_rank: Contributor
timestamp: March 06, 2020, 04:53:21 pm
content: The IEEE EMC society and the PSES run a listserv that is frequented by industry principals for compliance engineering. But they do not suffer fools or people wanting free engineering services.Recommend that you find the nearest local society chapter and attend their next monthly meeting. The EMC society and the PSES also hold several symposiums each year.
CE Noise Immunity and testing - Page 1
Forum section: electronics / projects

author: w3amd
author_rank: Regular Contributor
timestamp: February 16, 2016, 04:09:12 pm
content: Hi all,During testing we found we have an issue in: Conducted RF Immunity (EN 61000-4-6)Noise near 30 Mhz can somehow jump onto the instrumentation measuring circuits and seems to push the signal to one rail or another on the instrumentation op-amps from what I can determine. It also takes a very long time between starting the RF @ 2W on the cables and the final bad result (takes about 30 seconds or so).Is there a way with the Rigol DS815-TG to set up for a test to see how the chassis behaves at let's say 30 Mhz. I'm thinking we don't have a low enough impedance path on the shields from the wires through the chassis to PE. We've determined that by looping the cables (which happens to be 1/4 wavelength of 30 Mhz) between it's normal physical connector on the chassis and placing the shield to another area of the cabinet this causes the same problem.Can the Rigol TG be dead shorted? I'm assuming our cabinet does not have 0 ohms impedance at 30 Mhz but if it does will I break it?I think I should be measuring between the shield to chassis ground on the suspect connector and the actual star ground point back to the mains and seeing how much impedance this is near 30 Mhz? Am I on the right track? And how to go about doing this test?TIA,John
Cell (LiIon) Capacity Measurement Terminal Voltage, under load or open circuit? - Page 1
Forum section: electronics / projects

author: sleemanj
author_rank: Super Contributor
timestamp: August 12, 2017, 02:03:40 am
content: When measuring a, in this case, lithium-ion cell's capacity by way of discharge, is the terminal voltage (let's say 3v) determined reached under (let us assume a constant current) load, or open circuit?My assumption would be under load as the practical choice, but the couple of datasheets I've looked at don't really make it clear and open-circuit would make for better marketing numbers...Opinions?

author: sleemanj
author_rank: Super Contributor
timestamp: August 12, 2017, 09:38:21 am
content: Looking at some discharge charts, I've come to the conclusion that it must be at least charted as under load.The reason being that the charts show a lower start voltage for higher currents, so unless they are switching from under load at the start and open circuit at the end, it must be the under load voltage that determines when to finish the test.

author: BravoV
author_rank: Super Contributor
timestamp: August 12, 2017, 09:50:11 am
content: Here, suggesting to download this Sanyo/Panasonic specific document for this particular NCR18650GA cell ->http://www.hurt.com.pl/prods/bat/_li_ion/ncr18650ga.pdfIt has much detail than ordinary Panasonic single page Li-Ion specification sheet.Hope this clear things up.
Cell Certification - Page 1
Forum section: electronics / projects

author: matt111
author_rank: Newbie
timestamp: June 08, 2016, 04:56:00 pm
content: I am designing an embedded product that contains a micro controller interfaced to a cell module (Telit He910). The product will not be sold to any third party; it will only be used by employees to perform a service.I have a number of questions regarding required certifications:-Is PTCRB required if the product will only be used in Canada?-Is PTCRB required if the product will not be sold?-Is there a fine associated with operating devices on a network that are not PTCRB certified or is the only concern that the network will potentially kick the product off the network?-Other than PTCRB is there any other required certifications needed to operate in Canada?-Other than PTCRB and FCC is there any other required certifications needed to operate in the US?

author: Lord of nothing
author_rank: Super Contributor
timestamp: June 08, 2016, 07:58:29 pm
content: There is an Developer Board from Sierra Wireless.
Cell / mobile phone screen removal and refitting. - Page 1
Forum section: electronics / projects

author: DTJ
author_rank: Super Contributor
timestamp: May 01, 2017, 04:08:57 am
content: I've got a Samsung S5 with non functional erratic touchscreen operation.And am thinking of lifting the screen and checking the connectors were securely plugged in.I've not removed a screen before and was thinking of using my hot air rework tool set to say 80C to remove the screen.For those that have done this before, is the the right temperature range?Will the adhesive rebond again ok if I keep it hot and press it down as it cools?Cheers.

author: R005T3r
author_rank: Frequent Contributor
timestamp: May 01, 2017, 09:59:10 am
content: Hi,I've not worked on a Samsung S5 before, but I've sucessfully repaired a Lumia 545.First of all, you have to understand exactly what steps to do, otherwise you will end up in trouble. Take a look:(disassembly)(screen separation)Then, for the temperature setting, around 100°C should do the job. People use heat guns for that kind of repair, so it's not an issue.The LOCA glue is not reusable, whereas the adhesive that bonds the case to the LCD module is.I really hope it's only a lifted connector (but I doubt it) and you don't have to mess around with the touch screen module, since that module is between the LCD and the glass, furthermore it's glued and will need LOCA Uv glue (as an UV source you can use blacklight lamps). You will realize that separating the LCD from the glass is one of the most difficult repair ever, since it is very easy to damage the LCD module, so document yourself before taking any action.A tip I've learned at my expanses: be very careful in lifting the screen, since you don't want to go for over 40° from the lcd suface, or you will inevitably dent the lcd, and that operation will take a lot of time.

author: DTJ
author_rank: Super Contributor
timestamp: May 02, 2017, 01:36:11 am
content: Quote from: R005T3r on May 01, 2017, 09:59:10 amThanks R005T3R. I plan to only remove the LCD module from the case, so it's good news the adhesive is reusable.This phone has cost me nothing so there's not a lot to lose.
Cell phone antenna connector - Page 1
Forum section: electronics / projects

author: Rachie5272
author_rank: Regular Contributor
timestamp: May 14, 2017, 11:20:56 pm
content: I want to use an external antenna with my phone, but I have no idea what kind of connector it uses. Is it proprietary? Would I be better off swapping it with something else? The ones used for internal wifi seem rather ubiquitous. I can find cheap adapters to convert it to SMA, and then to a Yagi antenna. Does this make any sense?
cell phone battery - Page 1
Forum section: electronics / projects

author: Seekonk
author_rank: Super Contributor
timestamp: April 30, 2016, 07:50:07 pm
content: I just got a new replacement battery for an old LG cell phone. Upon unpacking the battery measured 0.00V. Pack has three terminals and don't think it is likely there is any electronics in the pack to disconnect the pins at low voltage. Seems like that would be in the phone. Normally I wouldn't give this much thought, but only one vendor on ebay even offers this battery. I popped it in the phone and for a couple minutes it acted like a near shorted battery with a blue LED keyboard light barely on. Then a couple minutes later the display came to life. Shortly after that measured the battery at 3.7V. My understanding was that once these dropped below 3V the cell would get permanent damage. This is a hard battery to find and wondering if it has a chance since it is new an apparently better quality (made in Japan). Any thoughts?

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: April 30, 2016, 07:53:44 pm
content: Likely the protection kicked in so it read 0v. If it's a rare battery it could have been in storage for months. If it took only a couple of minutes to reach 3.7V it's unlikely to be damaged and was just protected from further discharge.

author: SeanB
author_rank: Super Contributor
timestamp: May 01, 2016, 10:40:50 am
content: 3 pins means it has on board protection, like every cell phone battery aside from those glued into the case ( fruit company). The protection turned off the output as it went below 2V9 or so and then only allowed charging via the one body diode, till it got high enough to enable the second mosfet to enable discharge. If it lasts as long as the regular cell in use it will be fine.

author: Jeroen3
author_rank: Super Contributor
timestamp: May 01, 2016, 10:55:01 am
content: Even the fruit company batteries have a protection board directly on the tabs.

author: djQUAN
author_rank: Frequent Contributor
timestamp: May 01, 2016, 01:29:46 pm
content: At least you are sure it had a protection PCB.I got a few cheap ones before and these were what I got.http://www.quan-diy.com/misc/battery/fake.htm

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 01, 2016, 03:32:33 pm
content: Some batteries have a "shipment mode" that needs an initial charge to activate.
Cell phone minimum Rx signal level - Page 1
Forum section: electronics / projects

author: Jester
author_rank: Frequent Contributor
timestamp: September 11, 2018, 10:18:51 pm
content: Not sure what I can trust from Google search on this topic, has anyone done some real world testing of minimum signal level required for SMS data transfer?I tried using MD Faraday bag tester application on an Android.Normal signal level at test location -112dbmInside Faraday bag -127dbmInside one layer of foil -127dbmInside two layers of foil -127dbmInside two layers of foil and Faraday bag -127dbmSo I'm speculating the software has a -127dbm limitObviously varies from phone to phone, but roughly where is the cut-off point for no data?Thanks in advance to all that respond.

author: ahbushnell
author_rank: Frequent Contributor
timestamp: September 11, 2018, 10:24:00 pm
content: I would bet its 127dbm cutoff.Sent from my SM-G930V using Tapatalk

author: DaJMasta
author_rank: Super Contributor
timestamp: September 11, 2018, 10:32:40 pm
content: Do you know what radio chipset the phone in question uses? It's probably got a rated minimum for connection maintenance, then you just need to figure out what the gain of the antenna is.If not a software limit, it could be the noise floor of the device making the measurement. I think you need a more granular attenuation amount between -112 and -127 so you can see where the number stops changing. You could put a box over the phone and then just start heaping stuff on it when the test is run

author: amyk
author_rank: Super Contributor
timestamp: September 12, 2018, 01:32:32 am
content: 127 is 2^7-1, probably not a coincidence that it's the minimum measurable level.

author: Sceadwian
author_rank: Unknown
timestamp: September 12, 2018, 02:00:23 am
content: Generic google answer is -110 is about minimum for a crappy connection. But keep in mind SMS is inherently unreliable to begin with so if you have a connection THAT bad text messages can get lost for quiet a while if not left undelivered.If you need to be sure an SMS gets through to a location reliably -112 is not going to cut it.
Cell phone style push button - Page 1
Forum section: electronics / projects

author: Wilson__
author_rank: Frequent Contributor
timestamp: June 03, 2024, 10:00:31 pm
content: Any advises on very tiny sideway push button, typically as volume up/down on Android cell phone. Photo, drawing and where to buy.Many thanks

author: notsob
author_rank: Frequent Contributor
timestamp: June 03, 2024, 11:43:06 pm
content: Not sure of exactly what you are after, try searching for "navigation switch"here's one from from C & Khttps://au.mouser.com/datasheet/2/240/pts815-3050953.pdf

author: Phoenix
author_rank: Frequent Contributor
timestamp: June 04, 2024, 12:26:44 am
content: Try searching for right angle miniature tactile switch.

author: Wilson__
author_rank: Frequent Contributor
timestamp: June 04, 2024, 11:54:34 am
content: We are looking for these switch inside typical phone. Push top and bottom side is volume up and volume down.So far only see 3 x 3 mm and height 2mm. Smaller would be nicer but want to stay within lower end (smaller size) of 'industry norm' which imply easy supply and reliable perfromance.Many thanks

author: pcprogrammer
author_rank: Super Contributor
timestamp: June 04, 2024, 12:49:24 pm
content: What you are looking for is a custom made exterior push device for the type of switches Phoenix mentioned.If you want to know what is inside, try opening your phone and see for yourself.
cell signal booster - Page 1
Forum section: electronics / projects

author: dazq
author_rank: Contributor
timestamp: July 02, 2018, 11:17:15 am
content: so is there any vaility to thisas in do you think it works battery time range exc

author: PA0PBZ
author_rank: Super Contributor
timestamp: July 02, 2018, 11:31:06 am
content: Complete BS, in more ways than I care to describe.

author: Benta
author_rank: Super Contributor
timestamp: July 02, 2018, 04:02:45 pm
content: Seems like someone had a bunch of surplus components and decided to solder them into something and call it a "cell booster". It's probably just a short circuit in the end.

author: CopperCone
author_rank: Super Contributor
timestamp: July 02, 2018, 04:13:00 pm
content: I swear i saw a similar or identical looking circuit on youtube described as a cell jammer.

author: Benta
author_rank: Super Contributor
timestamp: July 02, 2018, 04:47:06 pm
content: Greatest part is: a BF495 has an fTof 120 MHz. Try using that for 2G/3G/4G
Cell simulator - Page 1
Forum section: electronics / projects

author: leblanc
author_rank: Regular Contributor
timestamp: December 19, 2016, 07:51:39 pm
content: Hello all,I have been trying to figure out a way of simulating 16 cell battery pack for a passive cell balancing circuit.In the past, we've used a large voltage divider to test the cell voltage measurement, i.e. supply followed by series resistors, with the cell taps in between each resistor. But this only works for testing cell voltage measurement, not for testing the actual cell balancing.My initial idea was to use several voltage shunt references on top of each other, I could adjust the cell voltages by adjusting the voltage dividers going into the voltage references. Not sure if that's a good idea.What do you guys think would be a good solution to create something that would behave more-or-less like a battery composed of 16 cells in series, with taps between each cell?

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: December 20, 2016, 04:03:10 am
content: If you are only thinking of simulating the circuit why not use 6 capacitors in series? You should be able to set the initial voltage of the caps as well.

author: leblanc
author_rank: Regular Contributor
timestamp: December 20, 2016, 01:17:41 pm
content: When I said simulate, I meant more "mimic the behavior of". It's still physical system that I will be building. It would just be incredibly unsafe to test a cell balancing system with actual cells.
Cellular IOT - Page 1
Forum section: electronics / projects

author: MidnightMohave
author_rank: Newbie
timestamp: March 12, 2022, 02:19:51 am
content: I am interested in doing a cellular IOT project. I have not selected my application yet, but I have a couple initial questions.1. Say I have an application that requires GPS, a camera, and possibly a Wifi AP. I could buy a processor, a cellular module, a GPS module, a camera module, and a wifi module and piece them all together. Or I could use a SOC like those found in all smart phones. Are there any cellular SOC development boards used by the common maker or is this unexplored territory? Perhaps these SOC chips require highly complex PCB design and proprietary software to program?2. The Particle Boron comes in two models, one that uses 2G/3G and has coverage in Europe. The other uses LTE Cat M1 and provides coverage in North America. However companies like Hologram offer SIM cards with global network coverage. So theoretically it should be possible to design a device with global support right? What platform could I use if I wanted my device to work globally? Perhaps global compatibility will require using a standard with higher power consumption?3. What is the best deal you have come across for SIMs with data? Monogoto looks pretty good at $0.35 per sim per month plus $0.01 per MB (In the US). A bit pricier in Canada at $0.17 per MB
Cellular module prepaid? - Page 1
Forum section: electronics / projects

author: Jester
author_rank: Frequent Contributor
timestamp: February 23, 2022, 04:32:09 pm
content: This ad from Digi-key got me wondering…https://info.digikey.com/index.php/email/emailWebview?mkt_tok=MTQ0LU5DQi0wMzAAAAGCxilpbCFTw8AYeyEkC8nTk4d-fzcu56AdNjpt4NMwPSu__pKF7PbNDhF9wC5VxgD0GQwdjAh-5KKkHbgbiyM_T43uLSDFMSMIEkILdJk8Eeis82M&md_id=69010Application would be intermittent SMS data perhaps once per day to a particular number in Canada. Data over a year would by less than 1MB.Want to avoid monthly fees and the need for registration with local cell providers.I’m not sure if a prepaid cellular module with a fixed amount of data exists?

author: coromonadalix
author_rank: Super Contributor
timestamp: February 23, 2022, 08:11:23 pm
content: Dont think so, normally you need to get an ''telephone number'' aka an activated sim card for a cellular modemThat way you'll be able to use an cellular network and be authorized to use it...OR maybe juste maybeIn m y country there is some frequency bands used for paget systems, now used for car starters .... no fees,But you have to get on it by other means ??

author: Someone
author_rank: Super Contributor
timestamp: February 23, 2022, 11:40:30 pm
content: Quote from: Jester on February 23, 2022, 04:32:09 pmIsn't that exactly what you linked to? Here is a cleaner link for those interested:https://www.digikey.com/en/product-highlight/b/blues-wireless/notecard-cellular-modem-somSounds like they have negotiated some bulk pricing (for low bandwidth high latency data) on enough carriers to provide pretty substantial coverage (but you still have several models with specific frequency ranges and regulatory+carrier approvals). But you are locked into their gateway/plan in the future. For small operations that should still end up cheaper than trying to negotiate your own service.

author: Someone
author_rank: Super Contributor
timestamp: February 23, 2022, 11:44:03 pm
content: Quote from: coromonadalix on February 23, 2022, 08:11:23 pmsoftSIM makes this sort of system practical

author: SL4P
author_rank: Super Contributor
timestamp: February 24, 2022, 12:22:30 am
content: Not much point looking for a data SIM plan if you’re going to be sending SMS messages…

author: Someone
author_rank: Super Contributor
timestamp: February 24, 2022, 01:03:52 am
content: Quote from: SL4P on February 24, 2022, 12:22:30 amData to SMS gateways can be cheaper than native SMS!
CellWise CW1104 - LiFePO4 Battery Pack Protection IC Datasheet - Page 1
Forum section: electronics / projects

author: SamJoc
author_rank: Newbie
timestamp: July 22, 2025, 10:55:27 am
content: Hello everyone,I'm working on a LiFePO4 battery pack and I'm trying to understand the BMS circuitry coming with it. The circuit employs an CellWise CW1104 battery pack protection IC, which seems to be a quite unknown IC and just minimal information about it can be found online. The "datasheet" just gives some basic information about the IC, but not really on the in depth functionality (no pin description whatsoever...).I attach the datasheet I found online and a photo of the IC. I'd be grateful if anyone has some information about the in depth functionality or a detailed datasheet.The print on the IC says:CellWiseCW1104SLCSLR13Thank you in advance!

author: squadchannel
author_rank: Frequent Contributor
timestamp: July 22, 2025, 11:52:12 am
content: instead of researching this ic, it is better to read the datasheets for ics from TI, ADI, and other manufacturers.cell balancing, two fets for charging and discharge protection, and temperature sensor input.there is not much difference to other products. other products has smbus and fuse control pins.
center tap transformer project - Page 1
Forum section: electronics / projects

author: grifftech
author_rank: Frequent Contributor
timestamp: April 04, 2019, 02:57:25 pm
content: the transformer is 24 volts with a 12 volt center tap, will this work?

author: MarkF
author_rank: Super Contributor
timestamp: April 04, 2019, 04:09:31 pm
content: Yes. But, I would add a few more components. A couple protection diodes, output capacitor and a LED.The LED provides a power 'ON' indication and more importantly a minimum load for the regulator.If you care to have a PCB made, it might look like this.
Ceramic capacitor cracking - Page 1
Forum section: electronics / projects

author: zenerbjt
author_rank: Regular Contributor
timestamp: August 30, 2020, 10:38:34 pm
content: Hi,This is the best thing ive read on ceramic cap crackinghttps://www.youtube.com/watch?v=QgKY5QWehME&feature=youtu.be...however, at 17:47 onwards, it seems to suggest that a lot of flexion can be tolerated....up to "4mm".I work with a PCB which is approx 15cm by 25cm and it has multiple 47uF, 16V, X6S, 1210 caps on it. They are placed in both directions, (so one of the directions is wrong).Being high value, the problem is worse, but i need the best ceramic cap crack video/tutorial out there to convince them that a change to Flexiterm/Thru-hole etc is worth while...they dont want to re-spin the PCB.Do you know of the best tutorial/video on this subject.?

author: temperance
author_rank: Super Contributor
timestamp: August 31, 2020, 12:35:42 am
content: Are those capacitors on the edge of the board? Ceramic caps usually crack when the board are being de-penalized and the capacitors are perpendicular to the board edge.If this is related to the question about connectors and connecting batteries, then inrush current is the problem.

author: zenerbjt
author_rank: Regular Contributor
timestamp: August 31, 2020, 09:11:23 am
content: Thanks, but no the ceramic MLCCs are away from the edge, but according to the video in the top post.....depanelization is just one factor, not the main factor. Its not clear though, how much board bending causes cracking...Thus if you bring this up in a company, and request changes, people just shrug it off and ignore it.

author: TheMG
author_rank: Frequent Contributor
timestamp: September 02, 2020, 10:36:57 pm
content: Just design the enclosure/chassis to be rigid enough and properly supports the PCB to avoid bending/flexing. Good support around areas of the PCB with any connectors which will be inserted/removed more frequently, etc

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 04, 2020, 03:26:32 am
content: Reminds me of a video where Davey Jones lets out the magic smoke of a 50V 20A power supply.In a followup video it's explained that ta ceramic cap just under the screw terminals was the culprit. You need to exert some force to the screw connectors for the 20A cable, which flexes the PCB and damages the cap.The simplest solution is to not flex the PCB (too much) during handling & mounting.Ther are special ceramic caps which have a little bit of flexibility built in, but you probably have to pay extra for that. Dave also did a video on those.
Ceramic capacitors - Page 1
Forum section: electronics / projects

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: January 07, 2023, 05:27:01 am
content: I found a small bag of ceramic capacitors in one of my component drawers. I have no idea where they came from.What would their application be, and how would they be mounted/connected? The circular ones are 1.3mm thick and measure around 1n2. The trapezoid ones are labelled as 1n.

author: srb1954
author_rank: Super Contributor
timestamp: January 07, 2023, 06:22:39 am
content: Quote from: BurningTantalum on January 07, 2023, 05:27:01 amThe trapezoidal ones are designed to be wedged into a slot in a PCB and blob soldered on each side so that there is zero effective lead length and practically zero ESL.The round ones could also be mounted in the same way but I have also seen them soldered face down onto a PCB for a very low inductance bypass capacitor with other components air-wired to the top face.

author: bidrohini
author_rank: Regular Contributor
timestamp: January 07, 2023, 07:37:56 am
content: Quote from: srb1954 on January 07, 2023, 06:22:39 amCould you please tell us how to solder these capacitors? I cannot see any legs like usual capacitors.

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: January 07, 2023, 08:53:44 am
content: Thanks SRB, that makes perfect sense. I guess they will go back in the drawer they came from!

author: srb1954
author_rank: Super Contributor
timestamp: January 07, 2023, 09:01:46 am
content: Quote from: bidrohini on January 07, 2023, 07:37:56 amThe slot in the PCB has Cu tracks right up to the edge of the slot. A blob of solder bridges from the Cu track to the side of the capacitor.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: January 07, 2023, 06:35:25 pm
content: Wow, I think Tektronix used these in the 1960s in the 1S1 and 1S2 GHz samplers. Never seen them as loose parts.

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 07, 2023, 10:27:30 pm
content: Nice piece of history.