Hobby Electronics Basics

Will this work safely?

Pressing the door button of my commercial wireless door bell causes the mains-powered speaker unit in the hall to chime...

10 comments posted 6yrs

posted by me

10 comments posted 6yrs posted by me

Inductance calculations

Somewhere there must be a formula for the inductance of a hand-wound coil. Air core, one layer of wire (of given swg) c...

5 comments posted 6yrs

posted by peterxpercival

5 comments posted 6yrs posted by peterxpercival

Harmon divider 10:1 and 100:1

Just found this neat method to make 10:1 voltage dividers. Not as important now that you can get such precision resisto...

3 comments posted 6yrs

posted by nojunk

3 comments posted 6yrs posted by nojunk

Anyone with plc experience?

I was looking for a ready made timer for a hydroponic system I'm tinkering with and came across some el-cheapo PLCs on...

5 comments posted 6yrs

posted by default

5 comments posted 6yrs posted by default

GFCI/lightening

I had a lightning strike hit an antenna mast and it took out a lot of electronics in my house. It actually popped circu...

2 comments posted 6yrs

posted by default

2 comments posted 6yrs posted by default

The Tardigrades

We can't just leave them there to die.

1 comments posted 6yrs

posted by snap

1 comments posted 6yrs posted by snap

Current vs. wire gauge

What current can 18AWG wire carry? And, more usefully, is there a table somewhere giving this info for all the usual gau...

7 comments posted 6yrs

posted by peterxpercival

7 comments posted 6yrs posted by peterxpercival

12 Vdc led running hot

I bought some 12 VDC 5 mm red leds. They work find but... when I touch the wires going into the led, they were hot enoug...

11 comments posted 6yrs

posted by scientist77017

11 comments posted 6yrs posted by scientist77017

Rebuild computer speakers

I bought some Inland Pro Sound 2000 speakers from a thrift store. It is an amplified system putting out about 7 watts....

2 comments posted 6yrs

posted by scientist77017

2 comments posted 6yrs posted by scientist77017

Two diode vs four diode rectification

What is the advantage of a four diode bridge full-wave rectifier over a two diode full-wave rectifier. There must be som...

19 comments posted 7yrs

posted by peterxpercival

19 comments posted 7yrs posted by peterxpercival

Isolation transformer?

I was looking for a 120-120 isolation transformer on eBay and I kept finding 120-240/480 transformers. There are 2 seco...

17 comments posted 7yrs

posted by BobEngelhardt

17 comments posted 7yrs posted by BobEngelhardt

Replacement NiMh battery for small solar light

I replaced a 600 Mah NiMh battery in a small solar light with a 2300 Mah since I had no 600 Mah hr batteries in my stoc...

1 comments posted 7yrs

posted by scientist77017

1 comments posted 7yrs posted by scientist77017

Soldering paste

I recently received this and am learning about what applications it is good for. https://imgur.com/3pGTm0a I put a smal...

10 comments posted 7yrs

posted by scientist77017

10 comments posted 7yrs posted by scientist77017

Dropbox test

https://www.dropbox.com/sh/lx4vkcno5thghc5/AAAQ0-_kBJz86FkV2-MN5Mxea?dl=0 Can non-Dropbox members open this folder and s...

4 comments posted 7yrs

posted by jjlarkin

4 comments posted 7yrs posted by jjlarkin

Seeking an enclosure...

Seeking an enclosure that looks like this from the side: +--- | \ | \ | \ | | +-------+ Think of a meter case, terminal...

8 comments posted 7yrs

posted by peterxpercival

8 comments posted 7yrs posted by peterxpercival