Hobby Electronics Basics

Controlling alot of LEDs from Arduino or AVR. Maybe 74HC595

I am trying to create a project much like like a Marquee sign, I want to be able to control hundreds of LEDs from a set...

4 comments posted 4yrs

posted by sidwelle

4 comments posted 4yrs posted by sidwelle

Why A DC to DC Converter Will Not Increase Range of the $3 Voltmeter Either

Guessing that there was no clever end run around the 30v maximum I tried a DC to DC converter set to 15v then measured...

2 comments posted 4yrs

posted by bretcahill

2 comments posted 4yrs posted by bretcahill

Why the $3 Voltmeter Cannot Work With Inline Resistance

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

0 comments posted 4yrs

posted by bretcahill

0 comments posted 4yrs posted by bretcahill

Cheap Voltmeter Doesnt Fry Over Voltage

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

0 comments posted 4yrs

posted by bretcahill

0 comments posted 4yrs posted by bretcahill

Jus Run the Voltage Backwars Thru a 8 v 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 t...

1 comments posted 4yrs

posted by bretcahill

1 comments posted 4yrs posted by bretcahill

220k Resistor Does Not Werk On 100 K Voltmeter

Hit just flashes. Furst guess is not enuff nano amps gits thru that yuge resistor. I ben very luky in that California n...

2 comments posted 4yrs

posted by bretcahill

2 comments posted 4yrs posted by bretcahill

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

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

6 comments posted 4yrs

posted by bretcahill

6 comments posted 4yrs posted by bretcahill

Free Energy or Energy Storage

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...

0 comments posted 4yrs

posted by tobiasgadelha

0 comments posted 4yrs posted by tobiasgadelha

by 90° in Capacitor ?

Many books told us that current leads voltage by 90° in capacitor. I have designed an experiment to show that it is true...

0 comments posted 4yrs

posted by yuenhonkeung

0 comments posted 4yrs posted by yuenhonkeung

Why are engineering sample CPUs illegal to sell?

Why are engineering sample CPUs illegal to sell?

41 comments posted 4yrs

posted by CK1

41 comments posted 4yrs posted by CK1

How long to charge 9v nimh battery

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

4 comments posted 4yrs

posted by scientist77017

4 comments posted 4yrs posted by scientist77017

MOV Search

Hello, I am an Alarm Technician among other things or stuff. I was thinking about installing a simple MOV on the Transf...

4 comments posted 4yrs

posted by somewhere

4 comments posted 4yrs posted by somewhere

DC motor soft start

I found this neat soft-start circuit on the eevblog forum. Its neatness is that the gate threshold voltage occurs immed...

6 comments posted 4yrs

posted by BobEngelhardt

6 comments posted 4yrs posted by BobEngelhardt

Potentiometer Project

I'm working on a custom project that involves potentiometers and picture adjustments on the monitor they are connected...

4 comments posted 4yrs

posted by Searcher7

4 comments posted 4yrs posted by Searcher7

the fable of the diode

Once upon a time, there was a village called Diode. The inhabitants were an excitable lot, who tended to get charged ea...

0 comments posted 4yrs

posted by r_delaney2001

0 comments posted 4yrs posted by r_delaney2001