Why the $3 Voltmeter Cannot Work With Inline Resistance

Started by Bret Cahill in sci.electronics.basics7 months ago 1 reply

The lowest voltage it can measure is what powers the LED display so something must be acting like a DC to DC converter set at the display...

The lowest voltage it can measure is what powers the LED display so something must be acting like a DC to DC converter set at the display voltage. Additional resistance in series lowers the current too much to power the display. It only works on an ideal voltage source.


Jus Run the Voltage Backwars Thru a 8 v Battery

Started by Bret Cahill in sci.electronics.basics8 months ago 1 reply

The Fieri light runs on 4 rechargeable cells 2p X 2s. Just wire it so that the voltmeter always gets 8 volts less than the ebike battery.

The Fieri light runs on 4 rechargeable cells 2p X 2s. Just wire it so that the voltmeter always gets 8 volts less than the ebike battery.


Converting a $3 / 30v Voltmeter to A 45 v Voltmeter.

Started by Bret Cahill in sci.electronics.basics8 months ago 6 replies

The impedance is 100k Ω. Put a 50 kΩ resister in series with the voltmeter and map out the correction.

The impedance is 100k Ω. Put a 50 kΩ resister in series with the voltmeter and map out the correction.


220k Resistor Does Not Werk On 100 K Voltmeter

Started by Bret Cahill in sci.electronics.basics8 months ago 2 replies

Hit just flashes. Furst guess is not enuff nano amps gits thru that yuge resistor. I ben very luky in that California no longer picks up toxik...

Hit just flashes. Furst guess is not enuff nano amps gits thru that yuge resistor. I ben very luky in that California no longer picks up toxik elektrikal stuff. But all I got is 2 resistors wif leads, .24 Ω and 220K Ω.


Cheap Voltmeter Doesnt Fry Over Voltage

Started by Bret Cahill in sci.electronics.basics8 months ago

It simply loses linearity. At least up to 38 v where it reads 36 v. Who cares?

It simply loses linearity. At least up to 38 v where it reads 36 v. Who cares?


Free Energy or Energy Storage

Started by Tobias Gadelha in sci.electronics.basics8 months ago

Hi Dears, I watched this video and I'm very curious if this is a really storage or fake. I know that free Energy don't exist but this energy...

Hi Dears, I watched this video and I'm very curious if this is a really storage or fake. I know that free Energy don't exist but this energy storage is real? Video Youtube https://uii.io/Energy__Storager


anti-music "remote control"

Started by Eli the Bearded in sci.electronics.basics9 months ago 3 replies

https://www.vice.com/en/article/jg8wnb/square-dancing-noise-china Residents who are fed up with the noise from China's ubiquitous ...

https://www.vice.com/en/article/jg8wnb/square-dancing-noise-china Residents who are fed up with the noise from China's ubiquitous "dancing grannies" are resorting to a special device that could mess with the speakers that blast out loud music. They use an infrared remote control dubbed "anti-square dancing magical device" to silence the noisy dancing troupes that have ...


Can anyone explain how this battery charger works?

Started by Commander Kinsey in sci.electronics.basics10 months ago 62 replies

https://imgur.com/a/b8l5qKQ Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a...

https://imgur.com/a/b8l5qKQ Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?


Why are engineering sample CPUs illegal to sell?

Started by Commander Kinsey in sci.electronics.basics10 months ago 73 replies

Why are engineering sample CPUs illegal to sell?

Why are engineering sample CPUs illegal to sell?


How long to charge 9v nimh battery

Started by AK in sci.electronics.basics11 months ago 4 replies

I have a 9V 180 ma discharged Nimh battery that I am charging at 25ma. How long will it take to charge? Thanks, Andy

I have a 9V 180 ma discharged Nimh battery that I am charging at 25ma. How long will it take to charge? Thanks, Andy


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