askelectronics

This magazine is from a federated server and may be incomplete. Browse more on the original instance.

Susan_B_Good, in Help Bypassing Timer on LED Lights

'fraid that a little bit of effort producing the circuit diagram from the boards is really needed.

I think that it will show what has to be a microcontroller with an input pad going to the switch and another pad going to a base resistor for q1. Q1 switching power to LEDS via RA - D.

The long light looks to be fitted for a an IR receiver. With U1 near it possibly the decoder. As they show the thing stuck on a rafter presumably way out of reach - I suspect that 's a picture from the version with an IR controller. They have produced a cheaper version, without the sensor and re-used the photos.

Now, if that’s how it is - I’d just remove the microcontroller and glue one of my favs upside down on the board and run wires from its pins to the relevant pads (removing the existing microcontroller). I haven’t bought one recently, but 8 pin ones were costing me less than 50p… Having programmed the replacement with an added option to stay on.

Susan_B_Good, in How to setup this function generator with this oscilloscope?

We have a council-supported “man cave” - with a couple of funded workshop technicians and lots of unpaid volunteer specialist engineers, mechanics, DIY’ers etc. Plus a very well equipped multi-discipline workshop. So you could take those bits of kit there and someone would give you a hand setting them up, teaching you how to use them, repairing them/maintaining them as needed. Even getting them calibration certificates (thanks to one of the volunteers who has access to calibration equipment). If you don’t have one locally - wouldn’t the technician at a local school/college/university help? Is there a local community online group that you could join and ask for help?

teri, in Help Bypassing Timer on LED Lights

For the first one: Would be good to know what U1 is exactly. Can you read any number/code on it?

If you are lucky it is simply a ‘switch’ which switches on once you press the button and switches of after 30min. In this case you could add a wire which constantly switches the lights on. Then add a normal mechanical switch to the power supply cables.

If you are unlucky, U1 also regulates the current through the LEDs. Then cannot be easily replaced. Is there anything on the other side?

allmycircuits,

First image: U1 says HZ300 0053, and Q1 says 3400A. The second image has two U1 components: the smaller says RCAKL9 00765, the larger is 6228A 2121/33, and the Q1 is 3400X. There’s nothing on the back of the board.

hardware26, in Help Bypassing Timer on LED Lights

Can you read what u1 and q1 are in the first image? Q1 looks like a transistor switch and u1 might be a counter. It may be counting a clock or it might be a comparator checking whether a capacitor is charged or discharged to check time. Is there any components on the other side of the board? I would expect a capacitor or oscillator at least for timing.

allmycircuits,

First image: U1 says HZ300 0053, and Q1 says 3400A. There’s nothing on the back of the board. The second image has two U1 components: the smaller says RCAKL9 00765, the larger is 6228A 2121/33, and the Q1 is 3400X.

Lazyhotodogu, in Diode Connection Mode MOSFET

For more context, This was about MOSFET used as Radiation detector

hardware26, in How to setup this function generator with this oscilloscope?

If you are completely new I suggest watching a tutorial. Otherwise some basic tips could be

  1. if oscilloscope has multiple channels, make sure the channel you connected is the channel nel you see on the screen
  2. make sure you did the ground connection. You need to connect both signal and ground tips if the probe
  3. make sure voltage range is fine. If you use a large range in the screen, little amplitude you got may seem like a flat line.
  4. calibrate your probe, if oscilloscope has that option. But an uncalibrated probe doesn’t explain flat line, it would explain distorted square wave, for example.
  5. Use another probe. They can get broken. If it is broken all you will see will be the noise the cable pics up like an antenna.
  6. separate the issue. Connect probe ends to a battery with k own voltage and see what you receive. If it doesn’t work, you know either probe or oscilloscope is wrong.

List can get longer really, but I think a tutorial and these can go a long way for the beginning.

EdvinYazbekinstein, in boosted 18650 circuit - parallel or series? Or doesn't matter?

youtu.be/_WI9Nwqvplo

If you haven’t considered this, it’s another option. You can make a USBC pd battery bank from 18650’s, or buy commerical ones.

Paired with a trigger board like this, it works well for projects. I’ve made a few from old laptop cells. youtu.be/DQLrZA5RMjQ

crm, in Help finding replacement charging jack

They are available on ebay, for example: https://www.ebay.com/itm/362503636436

OddFrog,

THAT’S IT thank you!

feidry, in Help finding replacement charging jack

As the other commentor said, ebay is a good place to look for such things but don’t search the part numbers. Search the model number of your device. Get the model number as specific as possible. Sometimes there’ll be a model number printed on the outside or on the box it came in, and that number is like a customer facing model number with a different model number that the manufacturer goes by. Like you’ll have a Samsung Note 8 and that sounds like the model, right? But in reality, it’s a SM-428Z-J12 or something. That’s the model number you want to search. Do some research on your device to get the right one.

OddFrog,

Thank you for the advice! Was starting to lose my mind scrolling pages of parts.

grasib, in High Voltage Capacitor Identification

Could be a Vishay MKP1848H54012xxY

That one matches by capacity and Voltage. Also the size seems more or less correct. Is it 2 or 4 pins? Do you need an exact replacement?

For Y:

2 is 2 pins,

4 is 4 pins 10.2mm

5 is 4 pins 20.3mm.

StillBald,

Thank you for the reply. The one we have on hand has 4 pins. An exact replacement would be great, but at this point if we can just get one to work, that'd be fine as well. I appreciate the help! I'll dig around and see if I can track down datasheets to review.

Susan_B_Good, in boosted 18650 circuit - parallel or series? Or doesn't matter?

The standard countryside yokel reply when asked for directions applies, " Arrh, If you need to get to there, I wouldn't be starting from here".

For battery powered LED lighting - you shouldn't be using 12v LED strips. You should be using bare LEDs and a constant current supply. Converting cell voltage to 12v, only to use (probably) resistors to limit LED current isn't the way to go.

You will lose far more, efficiency wise, starting from there, than you are worrying about losing in the series or parallel considerations.

But then, you'd design the required power source and then the charger associated with it - not start with a charger, which then constrains your battery pack topology.

OddFrog, in Help finding replacement charging jack

Searching for the number hasn't gotten me anywhere neither has searching by the dimensions of the jack. Would like to avoid stealing parts off other systems but as a last resort would consider it.

grasib, in boosted 18650 circuit - parallel or series? Or doesn't matter?

In general, what I remember from step up converters, is that they work more efficient the less they have to step-up. So a conversion from 4 to 12V is less efficient than a conversion from 8 to 12V.

But I also remember that after a certain input voltage the change in efficiency is only minimal. According to the datasheet of the MT3608 this seems to be around 4V.

Therefore I’d connect them in series, but I’m looking forward to other peoples input on this.

Welcome to Lemmy!

nirurin,

Unfortunately after posting this I discovered the TP4056 board won't charge 18650s in series, only in parallel!

JCreazy, in boosted 18650 circuit - parallel or series? Or doesn't matter?

Hello. I believe you are correct because power in=power out. Series would be more efficient as there would be less voltage to boost.

nirurin,

Since writing this though I realised something important I had forgotten - these are rechargeable cells. And if they are wired in series, it means I need a much more complicated charging circuit (I currently use TP4056 boards to charge cells).

So even though series might be more efficient, I think I'll need to use parallel as a single TP4056 can charge two cells in parallel.

Thanks for the answer though!

wizzor,

Funnily enough I have exactly the same set up on my healing bench right now, and was wondering about the same thing. Thanks for posting the question and your realization.

Susan_B_Good, in SBC UART debug troubleshooting

You probably have already sussed this - but:

DuPont connectors equates to logic level signals. There may even be a 3.3 v <>5v link selector on the adapter.

Whereas DB9 equates to "RS232" level signals. Generally, at least the capability to accept those voltage levels, even if not necessarily producing them.

My first step tends to be to connect tx to rx and see if characters typed in a terminal/emulator get echoed.

An RS232 breakout box is pretty much a given necessity, when it comes to sorting out what's happening on all those pins and sorting out what to connect to what.

  • All
  • Subscribed
  • Moderated
  • Favorites
  • askelectronics@discuss.tchncs.de
  • localhost
  • All magazines
  • Loading…
    Loading the web debug toolbar…
    Attempt #