Trying to understand math for Battery resistance ?

Started by StevWolf in sci.electronics.basics2 weeks ago 2 replies

I=E2=80=99m working though understanding this description in this book. see= attachment link below. I have tried this method for testing...

I=E2=80=99m working though understanding this description in this book. see= attachment link below. I have tried this method for testing household batteries. I know there are = other ways of testing batteries, but really I'm just trying to work my way = through this book as a personal exercise. Please refer to link below for the book example Im trying to follow. The ha= nd written notes are...


Ideas for a 12V brake light flasher circuit

Started by Joe in sci.electronics.basics1 month ago 4 replies

Hi, I'd like to try and build a brake light flasher circuit for a motorcycle (12V). Brake light should flash 3-5 times then remain on (solid...

Hi, I'd like to try and build a brake light flasher circuit for a motorcycle (12V). Brake light should flash 3-5 times then remain on (solid red). I'm new to electronics so not everything is clear to me. Is it possible to build such a circuit and remain in 12V "domain" or is it necessary to step down to 5V to power an IC (a counter with a clock, for example) ? I'd like to use a 12V LED bulb (e...


Phone no longer charges

Started by AK in sci.electronics.basics1 month ago 1 reply

I have a Samsung S5 cell phone. It just now stopped charging. ?? I have tried at least 3 different charging cables, and 3 different...

I have a Samsung S5 cell phone. It just now stopped charging. ?? I have tried at least 3 different charging cables, and 3 different chargers. I also removed the battery and did a factory reset. Anyone have any other ideas? Thanks.


How to know when to change battery in multimeter

Started by AK in sci.electronics.basics2 months ago 2 replies

On my multimeter, the voltage readings get inaccurate over time due to battery discharge. My meters all use 9 volt batteries. How can I tell...

On my multimeter, the voltage readings get inaccurate over time due to battery discharge. My meters all use 9 volt batteries. How can I tell when to change out the batteries? Thanks.


Recap On Absolute Cheapest Dummy Load

Started by Bret Cahill in sci.electronics.basics3 months ago

Eventually road 15 km against the wind in highest assist. The motor and refurbished battery were both uniformly warm. There were no hot spots...

Eventually road 15 km against the wind in highest assist. The motor and refurbished battery were both uniformly warm. There were no hot spots on the battery in the one minute dummy load test so this is not surprising. Range in medium assist increased from 40 km to 60 km, flat land no wind. Now the bad news. Water filter clogged up and I rummaged around for a fresh charcoal filter. Foun...


Absolute Cheapest Load To Test A Rebuilt Battery

Started by Bret Cahill in sci.electronics.basics4 months ago 5 replies

Need to draw 18 Amps from a 36 v battery. For 5 minutes. 2 lugs in a brine solution? Drive rebar into the ground?

Need to draw 18 Amps from a 36 v battery. For 5 minutes. 2 lugs in a brine solution? Drive rebar into the ground?


OT - Standby electrics - worth consideration?

Started by Charlie+ in sci.electronics.basics5 months ago 14 replies

I just worked out that in my (UK) house (with my children long gone!). The electric standby items are going to cost ?452 UKP per year at October...

I just worked out that in my (UK) house (with my children long gone!). The electric standby items are going to cost ?452 UKP per year at October 2022 going forward cap levels, and of course more again at the next cap level(s) in 2023. I have used 52 pence per kWh and 58 pence per day service charge. YMMV. Measurement was taken at the supply meter with no items full running. As a quick ...


Hear sounds from TV to my radio

Started by AK in sci.electronics.basics5 months ago 2 replies

I want to hear sound from my Tv using my standalone radio. All the TV output HDMIs are being used. My inputs on my radio for TV/Dbs are...

I want to hear sound from my Tv using my standalone radio. All the TV output HDMIs are being used. My inputs on my radio for TV/Dbs are coaxial. What parts do I need? Thanks.


Detect the turbidity

Started by Marcos Loyola in sci.electronics.basics6 months ago 2 replies

Hello good day! I need a simple circuit to detect the turbidity of the reuse water from the washing machine, that is, discard the 1st water and...

Hello good day! I need a simple circuit to detect the turbidity of the reuse water from the washing machine, that is, discard the 1st water and reuse the others, a very simple circuit for a low-income community. Thank you Marcos


Replacement for Li-Ion battery

Started by AK in sci.electronics.basics6 months ago 2 replies

I want to replace this 3.7 Volt Lithium Ion battery. The dimensions are 1 14/16 x 8/16 inch. Can some help me find a...

I want to replace this 3.7 Volt Lithium Ion battery. The dimensions are 1 14/16 x 8/16 inch. Can some help me find a replacement? Thanks, Andy https://imgur.com/a/w5v2dHI


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