Re: Swapping out a NiMh for a LiPo?
My design refreshes the battery exactly once every six weeks. Power interruptions will not change the schedule, and the location of this light is in a hallway where it's fairly dark all the time ... but I wouldn't even consider doing this without an RTC chip ... I don't see what the big deal is ... trying to do something with accuracy and reliability ...
As far as cost goes, this was a personal project ... I'm not trying to market the thing .. I had fun doing it, so the cost was irrelevant.
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Re: Swapping out a NiMh for a LiPo?
He never does things the simple wayLeave a comment:
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Re: Swapping out a NiMh for a LiPo?
and it still needs an external device to set the time...Leave a comment:
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Re: Swapping out a NiMh for a LiPo?
You have two batteries: the CR2032 and ... the Li-ion pack!
Up to you. Your money. Could have made the board smaller, less components, and thus cheaper... BTW yes this is depending on a low power microcontroller like the atmels, attiny, etc.Leave a comment:
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Re: Swapping out a NiMh for a LiPo?
I was talking about YOUR design where you said you would have skipped the RTC chip and just implemented the RTC in software ... you usually can't battery back the microcontroller, but the RTC chips are designed for that.
And NO, I only have ONE battery.
And YES, it does matter, because I want the circuit to discharge the battery when the day starts so that it can discharge, then charge and be ready to go by sundown ... as opposed to the unit discharging the battery at 6 pm then when the power goes out at midnight, I have no lights because my SOFTWARE RTC forgot what friggin time it was when the power went out...
Why in the world would you invest all that time writing a software RTC when you get the chips for a couple of bucks?Leave a comment:
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Re: Swapping out a NiMh for a LiPo?
A, isn't that what the battery is for? You have two batteries after all!
and B, does it really matter?
As long as it's clear, but this does not seem very clear. Then again for personal use it doesn't matter though.The light has an LED that indicates when it's getting power from main ... so when the lights are on and that LED is off ... yet their TV is still on ... probably a good indication that we're refreshing the battery ....Leave a comment:
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Re: Swapping out a NiMh for a LiPo?
So when the power goes out and your software RTC doesn't know what time it is when the power comes back on ... then what?
The light has an LED that indicates when it's getting power from main ... so when the lights are on and that LED is off ... yet their TV is still on ... probably a good indication that we're refreshing the battery ....Leave a comment:
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Re: Swapping out a NiMh for a LiPo?
some mcu's have an rtc,
most have hardware i²c so you dont need a bitbang library!Leave a comment:
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Re: Swapping out a NiMh for a LiPo?
What the... didn't even see you used a i2c rtc in the design... I would have just did the RTC in software and omitted a chip since it doesn't even need to be that accurate.
Other thing is that I probably would have added an LED that blinks while it's self-testing. Then the user wouldn't wonder why the light was on unexpectedly...Leave a comment:
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Re: Swapping out a NiMh for a LiPo?
you have no high level coms running afaik, just talking to an RTC.
so what pain? your just reading some registers and running some loops.
as a halfway, you could copy the library's and rename them.
then delete every function from the library's that you arent actually using.Leave a comment:
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"wonderful" design...
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Hello.
I have seen a short circuit tester made with 3 * 9V batteries, a voltage limiter component and a resistor connected to the probes of a multimeter.
The theory is that the meter becomes sensitive enough to read very low resistances and the lowest resistance to ground on a circuit is likely to be a short circuit in that area.
Link
The Amazing $1 Short Finder Upgraded! Convert ... - YouTube
https://www.youtube.com/watch?v=0eixDdCpiO4
My multimeter isn't normally sensitive to very small resistance, but when I put a 1 mega ohm resistor... -
Hi,
I am repairing a ups which doesn't turn on ,it has the following ICs:
SG3525 used to drive inverter mosfets.
couple of uc3483, one for the power supply and another to drive a big mosfet at the output stage(i think the technique is called boost)
A LM358 and TL074 for control mechanism and of course the uController.
The SG3525 is shutting down every time the ups is turned on.
I want your help to know the function of LM358 and TL074 in the system.
I reverse engineered the LM358 circuit and i think that one of the block(A) is used for battery level... -
Hello. MSI B250 Gaming M3 board, short-circuit on the power supply. Found a problematic mosfet VQ1
(N-PK616BA_PDFN8-HF) soldered it out - short circuit is gone. I replaced VQ1 + VQ5 (N-PK632BA_PDFN8-HF). VQ1 was replaced with PK618. After starting attempt VQ1 is lit again. What can be the problem? In the driver?
Schematic and Boardview here
...04-04-2025, 03:57 PM -
So I have a cheap non working ATX PSU that I was learning to repair a decade ago. At the time, it blew the main fuse, bridger rectifier, NTC, and primary 9A 900V MOSFET. Replaced all except the MOSFET. 5VSB came back online. Then I poked around in it so much, measuring components one by one to a point I accidentally made the 5VSB circuit primary side went bang. Blown the AP8022 (Viper22A) PWM chip, along with a low resistance resistor and the PC817 opto isolator. I replaced them all.
In the process of poking around, I also lost a zener diode that stabilize the voltage coming from... -
A few days ago, I purchased MESR-100 ESR meter, and When I measured a SMD capacitor on circuit,MESR-100 showed ESR value of 30, But I managed to desolder this SMD capacitor from circuit and measured it then MESR-100 showed ESR value of 18.
I also measured it with Mega328 Transistor Tester, and It showed ESR value of 17.
Is my MESR-100 defective, if the ESR value is different between on Circuit and off Circuit?
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