Search found 184 matches

by labview1958
Sat May 20, 2006 9:08 am
Forum: General Discussion
Topic: USB port and dc motor
Replies: 6
Views: 1994

usb port

Nowadays there is a remote USB port. Can that be used to control a dc motor?
by labview1958
Thu May 18, 2006 12:32 am
Forum: General Discussion
Topic: USB port and dc motor
Replies: 6
Views: 1994

USB port and dc motor

Is it possible to control the speed of a dc motor via a USB port and pc?
by labview1958
Wed May 17, 2006 5:30 am
Forum: General Discussion
Topic: simple noise meter
Replies: 18
Views: 4632

noise meter

Where can I buy a ready made sound meter that mesures sound as heard by the human ear. I am interested in reducing human noise. Noise caused by people talking loudly. Is there a way to reduce such noise by some scientific method. If people knew their noise level, then maybe they would shut up.
by labview1958
Mon May 15, 2006 9:08 am
Forum: General Discussion
Topic: pwm circuit.
Replies: 2
Views: 1092

pwm

Is it possible to get smooth motion with a duty cycle of 0.1?
by labview1958
Sun May 14, 2006 2:54 pm
Forum: General Discussion
Topic: pwm circuit.
Replies: 2
Views: 1092

pwm circuit.

I have designed a pwm circuit controlled by a computer. I can get the dc motor to move from the duty cycle 1.0 down to 0.3. However it starts to stall and pulses at duty cycle 0.2 and 0.1. I have increase/decreae the frequency but it is no use. Is there a way to move the dc motor at constant speed a...
by labview1958
Thu May 11, 2006 5:23 pm
Forum: General Discussion
Topic: simple noise meter
Replies: 18
Views: 4632

noise meter

Does the microphone picks up all the noise as a human ear?
by labview1958
Thu May 11, 2006 9:40 am
Forum: General Discussion
Topic: simple noise meter
Replies: 18
Views: 4632

noise meter

How to make a simple one?
by labview1958
Thu May 11, 2006 8:35 am
Forum: General Discussion
Topic: simple noise meter
Replies: 18
Views: 4632

noise meter

How do I convert the noise from the trafic in front of my house to a voltage? Do I use the microphone?
by labview1958
Thu May 11, 2006 2:37 am
Forum: General Discussion
Topic: simple noise meter
Replies: 18
Views: 4632

simple noise meter

I want to make a simple noise meter. The purpose is to detect the noise level outside my house. I want to measure the noise level. I am looking for a sound sensor plugged to a chip that converts sound to voltage and conected t a voltmeter. Any ideas?
by labview1958
Wed May 10, 2006 2:38 am
Forum: General Discussion
Topic: 74F14 inverter
Replies: 14
Views: 3450

74F14

The link is to a description to the 74F14 and not it's application diagram I am looking for an application diagram for 74F14. I have looked at Fairchild and national semiconductor but no luck. Anyone knows where to get one? Basically I want to connect LM to the 74F14 and then to the NI 6025E daq boa...
by labview1958
Sat May 06, 2006 4:41 pm
Forum: General Discussion
Topic: LM2917 frequency to voltage regulator
Replies: 14
Views: 4041

LM2917

"Actually I have a few disk that are painted matt black. Each disk has a reflective aluminium tape attached to it. However the width of the tapes are not the same. Some are wide while others are narrow. I have already calibrated the rpm using a disk with a narrow tape. Can I keep the same calibratio...
by labview1958
Sat May 06, 2006 3:26 am
Forum: General Discussion
Topic: LM2917 frequency to voltage regulator
Replies: 14
Views: 4041

LM2917

Actually I have a few disk that are painted matt black. Each disk has a reflective aluminium tape attached to it. However the width of the tapes are not the same. Some are wide while others are narrow. I have already calibrated the rpm using a disk with a narrow tape. Can I keep the same calibration...
by labview1958
Fri May 05, 2006 4:28 pm
Forum: General Discussion
Topic: LM2917 frequency to voltage regulator
Replies: 14
Views: 4041

LM2917

What I meant was should the voltage vary with the surface area of the reflective portion of the disk or just depends on the frequency only?
by labview1958
Fri May 05, 2006 8:32 am
Forum: General Discussion
Topic: LM2917 frequency to voltage regulator
Replies: 14
Views: 4041

Frequency to voltage

I have a rotating disc with 10% reflective surface and 90% absorbtiive surface and another disk with 90% reflective surface and 10% absorbtive surface. If I rotate both at 1000 rpm would the voltage output be the same?
by labview1958
Tue May 02, 2006 3:45 pm
Forum: General Discussion
Topic: floating power supply
Replies: 9
Views: 2866

floating power supply

The lab power supply in my lab has a positive, negative and a ground. A battery has a positive and negative terminal. If I connect my circuit to the positive and negative supply of my lab power supply, then it acts as a battery. Is that right? What use is the ground then? The battery does not hve gr...