Engineering - March 2007

I'm doing an invention for a science project and I need a motion sensor that could be rigged to move with you.

2007-03-15 08:49:19 · 2 answers · asked by dude44 3

I know the gain is 1+(R2/R1), but the full derivation isn't written in my notes and I need it for a piece of coursework, please help!

2007-03-15 08:48:47 · 2 answers · asked by wonder.crumpet 2

I'm trying to find out if an air conditioning unit requires 1 phase or 3 phase power. All I know is that the voltage is 208/230V. Is there any way to tell from this if the power is single phase or three phase?

2007-03-15 08:28:03 · 12 answers · asked by glazedham42 1

2007-03-15 08:05:47 · 10 answers · asked by david 1

I need help with using a conversion reactor. The main issue is that the compounds I am using are hypothetical. I need help determing the relevant information for starch, glucose and fructose. If anyone has any experience with this, please contact me jonnyryer@hotmail.com

2007-03-15 07:59:32 · 1 answers · asked by Jon R 2

Hi all,

I want to know if any town in Germany is famous for its concentration of optics / lens-making industries. Specifically, I am looking for small scale lens-making factories there.

Thanks.

2007-03-15 07:43:21 · 1 answers · asked by gfehkltd 2

Actually, I am trying to find a power supply for a vintage guitar effect pedal: Ibanez cs-505 which runs on 2 9v batteries but that is the only info available.

2007-03-15 06:57:16 · 4 answers · asked by Actaeus 1

what are some examples of wedges (simple machines)

2007-03-15 06:56:00 · 5 answers · asked by fromwhereyouaree<3 2

2007-03-15 06:27:00 · 3 answers · asked by Jearld A 1

The case fan specs are:

Rated Voltage 12 Volts
Voltage Range 6.5 ~ 13.8 Volts
Input current 0.30 Amp Max
Input power 1.8 Watts Max
Rotation speed 1000 RPM

I have found a 5v to 12v DC-DC convertor from maplin, it all seems too simple, converting the 5v DC from the external USB port to 12v with a single chip http://www.maplin.co.uk/module.aspx?ModuleNo=98174&doy=15m3#overview

This is going to be an external fan and i cannot utilise the 12v feed from the PSU.

Does this seem like an ok solution?

Thanks

2007-03-15 06:19:26 · 3 answers · asked by reme j 1

A stepdown transformer with a 120-volt primary and a 24-volt secondary has a load impedance of 18 ohms across its secondary winding. What is the approximate reflected impedance "seen" at the primary

____a. 3.6 ohms

____b. 33 ohms

____c. 90 ohms

____d. 450 ohms



i am taking an electronics course and i am having trouble with this question. could you please explain how you came up with your answer and show any formulas that you used

2007-03-15 05:58:21 · 3 answers · asked by ken s 6

2007-03-15 05:40:51 · 5 answers · asked by SAR 1

2007-03-15 05:39:53 · 4 answers · asked by SAR 1

2007-03-15 05:32:45 · 11 answers · asked by SAR 1

2007-03-15 05:28:47 · 7 answers · asked by Selva r 1

2007-03-15 05:13:48 · 3 answers · asked by sivaraman l 1

for connecting lighting load it is necessary for provide seperate earthig for ups alone?reason

2007-03-15 05:10:14 · 1 answers · asked by sivaraman l 1

i have hard that it can hold a strong charge for as long as a year, where are these charges kept inside of the crt
is it in the focusing coils

2007-03-15 04:51:23 · 6 answers · asked by macgyver 1

I need 2 amperes for a circuit, but I can't decide how to get it. Voltage doesn't really matter. Should I try stepping down wall current? I want this to be as cost efficient as possible. Any ideas?

oh, and I would like to be able to change the current from between like 1.5 amps and 2.3 amps if that is possible.

2007-03-15 04:18:30 · 4 answers · asked by metaphysics1221 2

2007-03-15 03:59:18 · 9 answers · asked by Anonymous

Actually it trips the Generator if "Differential Protection" acts. Say if protection fails what will happen and what are the effects.

2007-03-15 03:17:47 · 1 answers · asked by MUNUSWAMY 1

the graph of vi characteristics of lcd, led

2007-03-15 03:02:26 · 2 answers · asked by Anonymous

CRO is cathode ray oscilloscope a device used in labs for signal detection. usually it gives a green display.a CRT cathode ray tube is the heart of CRO.

2007-03-15 02:39:24 · 1 answers · asked by apvnilambur 1

2007-03-15 01:51:24 · 10 answers · asked by cheryl 1

A fire helicopter carries a 620-kg bucket at the end of a cable 20.0m long. As the helicopter flies to a fire at a constant speed of 40m/s, the cable makes an angle of 40 degrees with respect to the vertical. The bucket presents a cross-sectional area of 3.80m sq in a plane perpendicular to the air moving past it. Determine the drag coefficient assuming that the resistive force is proportional to the square of the bucket's speed.

2007-03-15 01:03:15 · 2 answers · asked by jon_pete2000 1

An organ pipe contains oxygen gas at 47C resonates at a frequency of 300Hz,if the pipe is now filled with nitrogen gas then for the organ pipe to resonate at 300Hz what should be the temperature?
is the ans 7C or 41.1C

2007-03-15 00:54:25 · 2 answers · asked by Anonymous

I have seen photo albums which is said laminated with thermal film for greater protection

2007-03-15 00:42:10 · 3 answers · asked by gt75mehta 1

IN UPS SYSTEMS OR CNC SYSTEMS(CNC M/C'S) NEEDS PREVENTIVE MAINTENANCE TO PCB'S(ELECTRONIC CARDS) i.e. clean the cards and keep dust proof why cards should be dust free?

2007-03-15 00:34:11 · 5 answers · asked by gopalsingh 1

Do those testing for jobs as an engineer get to use calculators? The reason I ask is that I took a test for the DOT as an electrician and at the testing facility, everyone that was testing for just about everthing else, got to use a calculator. Being an electrician, I am quite used to this treatment, but it made me stop and think. You wouldn't want your banker working #'s without a calculator, nor just about any other profession, and in that regard I wouldn't want an electrician figuring out loads without one either. It seems that when testing, they are singled out to raise the bar and be smarter than anyone else. My question is, in this day and age why would they not be allowed to use a calculator when everyone else is allowed? Wouldn't you want to know if they could in a real world situation, come up with right answers in a proof positive way, or would you rather they just wing it ?

2007-03-14 23:42:10 · 10 answers · asked by lilredtop 1

the liquid metal mercury which is found in thermometers and stuff .. etc etc

2007-03-14 22:41:54 · 11 answers · asked by mike m 1