Hobby Electronics Basics

Is this scheme reasonable?

I have an automatic opening trash can in the kitchen that runs off of batteries. I wanna run it with a wall wart. When...

49 comments posted 9yrs

posted by etpm

49 comments posted 9yrs posted by etpm

OT: a great TV show if you like to tinker with stuff

I'm watching this really interesting program from the BBC. It is called (James May) "The Reassembler." He takes everyda...

11 comments posted 9yrs

posted by default

11 comments posted 9yrs posted by default

What is a load line - intuitively

http://pix.toile-libre.org/?img=1493527288.png That's a typical graph of Vce vs Ic for a bunch of Ib as provided by the...

10 comments posted 9yrs

posted by vek.m1234

10 comments posted 9yrs posted by vek.m1234

Transistor Hard Saturation - pg224 - Malvino

'A designer who wants a transistor to operate in the saturation region under all conditions often selects a base resist...

2 comments posted 9yrs

posted by vek.m1234

2 comments posted 9yrs posted by vek.m1234

connecting a VSD/VFD to an AC compressor

I was wondering about using a Variable Speed AC Drive for two air conditioners. One is a window unit, with rotary compr...

8 comments posted 9yrs

posted by default

8 comments posted 9yrs posted by default

PID tuning. Lag = ~ integrating time

Hi all, this is not so much a question, as me just spouting. If I do say (spout) something wrong, or that you disagree...

38 comments posted 9yrs

posted by gherold

38 comments posted 9yrs posted by gherold

Thermopile power supply in water heater control

I recently bought a gas water heater and made a point of getting one that didn't require external electrical power to o...

12 comments posted 9yrs

posted by bp

12 comments posted 9yrs posted by bp

one transistor amplifier help

I have the following amp. It originally had a 12V supply voltage, In an effort to get a larger swing on the output, I r...

21 comments posted 9yrs

posted by nojunk

21 comments posted 9yrs posted by nojunk

'K' type thermocouple wire connecting to meter - a question

I have a meter with K type thermocouple. The wire welded blob at the measuring tip is discoloured from the manufacture...

5 comments posted 9yrs

posted by charlie

5 comments posted 9yrs posted by charlie

Mystery component marking

I have two versions of the same USB adapter module. One has what I believe is an SMD jumper marked "000". At the same pl...

2 comments posted 9yrs

posted by waybackNO584SPAM44

2 comments posted 9yrs posted by waybackNO584SPAM44

Slip ring questions

I'm sure someone here can help. I need to get power to a solenoid operated valve spinning at 5000 RPM. Low power, 24 vo...

16 comments posted 9yrs

posted by etpm

16 comments posted 9yrs posted by etpm

Variac question

All, I have two variacs, one is the typical type that does not isolate the load from the mains. The other one I have is...

16 comments posted 9yrs

posted by etpm

16 comments posted 9yrs posted by etpm

contact surface material

I made an exposed lid switch consisting of two mating pairs of flat brass s tock about 1 x 1/2 inches. When I close the...

14 comments posted 9yrs

posted by fritzo2ster

14 comments posted 9yrs posted by fritzo2ster

Bnc impedance

So I am using rg 62 coax which is 92 ohm. My BNC connectors are 75ohm.all my equipment inputs and outputs are 92ohm. Do...

20 comments posted 9yrs

posted by jfisher864

20 comments posted 9yrs posted by jfisher864

Ground is no longer at ground potential

Scientists have determined that ground is no longer at ground potential. It dont matter if you're referring to the grou...

35 comments posted 9yrs

posted by oldschool

35 comments posted 9yrs posted by oldschool