Search found 2778 matches

by haklesup
Fri Feb 28, 2003 1:46 pm
Forum: General Discussion
Topic: generate sensor signal
Replies: 9
Views: 2000

Re: generate sensor signal

A resistor will not reduce the voltage unless there is current flowing through it. What you want is a resistor divider. If you want to create a node that is 1V and proportional to the battery voltage, you will need at least 2 resistors. Connect both in series from the pos to the neg terminal. Seclec...
by haklesup
Wed Feb 26, 2003 11:55 am
Forum: General Discussion
Topic: Black Box
Replies: 4
Views: 994

Re: Black Box

sounds like you could make the same thing out of almost any power supply with a variable current limit. Connect the common to the aluminum hull of the boat and the output to the cable. Turn the voltage all the way up and the current limit all the way down. Adjust the current limit for the desired ef...
by haklesup
Mon Feb 24, 2003 6:40 pm
Forum: General Discussion
Topic: Electronics Design Career Info
Replies: 4
Views: 1112

Re: Electronics Design Career Info

There is also the big company - small company split. In a large organization, designers (as well as all job functions) will tend to be more narrowly defined but the person gets much more in depth. This is where you find the real experts.<p>In a small company like mine, the designer may be forced to ...
by haklesup
Tue Feb 18, 2003 7:02 pm
Forum: General Discussion
Topic: Rare Earth Neodymium Magnets
Replies: 6
Views: 1127

Re: Rare Earth Neodymium Magnets

First a comment about heating magnets up to kill them. I found this quote in a magnet FAQ at http://www.wondermagnet.com/dev/magfaq.html#q17 Ferromagnetic materials heated above a certain temperature, known as the Curie Temperature or Curie point, completely lose their ferromagnetic behavior. The ma...
by haklesup
Sun Feb 16, 2003 11:48 pm
Forum: General Discussion
Topic: Circuit help wanted
Replies: 1
Views: 657

Re: Circuit help wanted

If your talking about a video phone, even the pros didn't get that right until only the last few years and they had to design special purpose IC chips to implement it. Problem is bandwith, you need to compress the video quite a bit to get it through the wire. <p>Still photos would be easier, many ne...
by haklesup
Sun Feb 16, 2003 11:29 pm
Forum: General Discussion
Topic: Ultrasonic Bird Repellers????
Replies: 14
Views: 2884

Re: Ultrasonic Bird Repellers????

Recall that 20kHz is generally recognized as the upper end of human hearing (at least by Hi-Fi and speaker manufacturers)and many people have better hearing than that (especially children)<p>If I had a 15kHz speaker screaming at 110dB I would expect to hear it and be annoyed. you might not want a "n...
by haklesup
Fri Feb 14, 2003 3:07 pm
Forum: General Discussion
Topic: Ultrasonic Bird Repellers????
Replies: 14
Views: 2884

Re: Ultrasonic Bird Repellers????

I take it back about ultrasonic repellers<p>This site www.bird-x.com makes one that outputs 15kHz to 25kHz at 98dB to 105dB through 4 loudspeakers. They also have other solutions.<p>Plastic Owls generally only work for a few days until the birds realize that guy is going nowhere. Add some sound and ...
by haklesup
Fri Feb 14, 2003 2:33 pm
Forum: General Discussion
Topic: Ultrasonic Bird Repellers????
Replies: 14
Views: 2884

Re: Ultrasonic Bird Repellers????

I don't think birds give a #a$%& for ultrasonic noise. Even if they do precieve it, they would likly get used to it after a while anyway.<p>Look at the problem from a behavioral point of view. Deprive them of the dogs food (the dog will get used to a new location - like inside a small doghouse) and ...
by haklesup
Tue Feb 11, 2003 5:23 pm
Forum: General Discussion
Topic: Ring Tones and Graphics
Replies: 5
Views: 933

Re: Ring Tones and Graphics

Dial 611 and ask the customer service rep from your cell phone company. I had a few questions about a different phone that were poorly explained in the manual and they were helpful
by haklesup
Wed Feb 05, 2003 12:47 pm
Forum: General Discussion
Topic: Voltage measurement of Zener Diodes???
Replies: 9
Views: 1283

Re: Voltage measurement of Zener Diodes???

Use sufficient current limiting to prevent damage to your diodes. Less than 1mA is usually safe. You can probably go much higher with most diodes but don't get carried away.
by haklesup
Tue Jan 28, 2003 2:55 pm
Forum: General Discussion
Topic: Wireless voice control
Replies: 3
Views: 1149

Re: Wireless voice control

Paul,<p>There are plenty of wireless microphones out there from toys to pro equipment. You should be able to feed the output of the reciever into the mic input on your soundcard instead of an amplifier. Add some speach recognition software (I saw some in the store and have had some bundled with soun...
by haklesup
Thu Jan 23, 2003 6:06 pm
Forum: General Discussion
Topic: PIR portable alarms
Replies: 5
Views: 1488

Re: PIR portable alarms

The easiest way, assuming you don't want to buy something different would be to replace or somehow parallel the beeper with a relay. You may need to boost the signal meant for the beeper with a transistor so you have enough current to pull in the relay. An FET solid state switch would probably also ...
by haklesup
Wed Jan 22, 2003 4:01 pm
Forum: General Discussion
Topic: crystal rating
Replies: 7
Views: 1085

Re: crystal rating

It can't be 16kHz since the lowest frequency crystal I see in catalogs is 1.0MHz or 1.544MHz and the highest is around 150MHz<p>If the P/N were to be interpreted as 1600kHz then that would make it 1.6MHz which dosen't seem to be a common value in these same catalogs. Most jump from 1.544 to 1.8432MH...
by haklesup
Fri Jan 17, 2003 11:10 am
Forum: General Discussion
Topic: Waves Converter
Replies: 38
Views: 5623

Re: Waves Converter

Michael, check the replies to your private messages by clicking on the "My Profile" link at the top of the Forum page.
by haklesup
Mon Jan 13, 2003 4:01 pm
Forum: General Discussion
Topic: heated bobbers
Replies: 7
Views: 1527

Re: heated bobbers

That may be a tough nut to crack. A fair amount of engineering is needed to match the heater, the battery and the operating conditions (cold and wet)and put in a package that meets the need. Problem is power density. Heating elements tend to draw large amounts of power while batteries are limited in...