Hobby Electronics Basics

diy thermometer sensitivity

I have a need to measure temperature accurately from 78.0 C to 79.0 C (eventually I'll need to turn on a solenoid valve...

91 comments posted 13yrs

posted by mrdarrett

91 comments posted 13yrs posted by mrdarrett

Air Purifier UV Bulbs

Are air purifier UV bulbs 120 V AC or do they need some kind of power supply? http://www.iallergy.com/product_info.php?p...

2 comments posted 13yrs

posted by BretCahill

2 comments posted 13yrs posted by BretCahill

Electric scooter speed contoller

Hi guys, I scored an electric scooter on trash day. (A Schwinn zone 5) Of course the SLA batteries were toast. (2 X 12V...

9 comments posted 13yrs

posted by ggherold

9 comments posted 13yrs posted by ggherold

Solar Battery Charger

Hi all, Green Batteries offers a large selection of high quality portable solar pan els, solar battery chargers, solar...

0 comments posted 13yrs

posted by grenbatteries

0 comments posted 13yrs posted by grenbatteries

what is active power

http://www.cirvirlab.com/index.php/electric/100-active-power-reactive-power -and-apparent-power.html Product of sine wa...

0 comments posted 13yrs

posted by pchung705

0 comments posted 13yrs posted by pchung705

How to clean my tuning capacitor?

It's an old (1960s AM radio) air dielectric, planetary drive with ball bearing 6X reduction). It's a very small mechani...

19 comments posted 13yrs

posted by bperryb

19 comments posted 13yrs posted by bperryb

9 LED flashlight batteries question

Have a sh** load of the above. Get them free when shopping at Harbor Freig ht. Lately, when batteries fail, I started c...

24 comments posted 13yrs

posted by ivanvegvary

24 comments posted 13yrs posted by ivanvegvary

viewing posted schematics on this site

I am unable to view schematics posted on this site. I have changed to the recommended mono-font and still no luck. The...

10 comments posted 13yrs

posted by ivanvegvary

10 comments posted 13yrs posted by ivanvegvary

two way communication

Hi. As it looks like i will have to make two way communication / control with my mcu based device - over net. Start/sto...

2 comments posted 13yrs

posted by igor

2 comments posted 13yrs posted by igor

Freezer Alarm

Im want to build this circuit. http://www.discovercircuits.com/PDF-FILES/FREEZERALARM1.pdf I am a novice at this. The d...

8 comments posted 13yrs

posted by stevesemple

8 comments posted 13yrs posted by stevesemple

OT? TV Uinversal Remote

Hello, Anyone in here know of a TV Remote Control that has the ability to change channels per a schedule?? TIA Les

20 comments posted 13yrs

posted by nospamhere

20 comments posted 13yrs posted by nospamhere

Sorting resistors

Trying to sort through 100's of resistors. Do you all sort them by the third color band, or do you get down finer than t...

25 comments posted 13yrs

posted by ivanvegvary

25 comments posted 13yrs posted by ivanvegvary

printed inductors

When an inductor is printed on a PCB in the shape of a 'square wave' or square zigzag, each time it zags the trace doub...

44 comments posted 13yrs

posted by tomd_u1

44 comments posted 13yrs posted by tomd_u1

Timer problem with Parallel port monitoring

Hey everyone, I'm very much so a newbie at electronics, but figured I'd try and tackle a problem for my scout group: ma...

9 comments posted 13yrs

posted by amcgillis

9 comments posted 13yrs posted by amcgillis

Wikipedia: threat or menace?

So while reading up on air-core inductors I encountered three formulae for calculating the inductance of cylindrical in...

19 comments posted 13yrs

posted by stevet810

19 comments posted 13yrs posted by stevet810