Search found 2788 matches

by haklesup
Thu Mar 13, 2003 4:53 pm
Forum: General Discussion
Topic: Tips for removing residual solder?
Replies: 7
Views: 1274

Re: Tips for removing residual solder?

More precisely, the gold forms a thin intermetallic layer that is an alloy of the two metals (actually 3 or more since solder is already an alloy). The thickness of this layer depends on the grain size and excat composition of the base metal (gold or gold alloy) and the temperature it was applied et...
by haklesup
Thu Mar 13, 2003 3:35 pm
Forum: General Discussion
Topic: Tips for removing residual solder?
Replies: 7
Views: 1274

Re: Tips for removing residual solder?

Assuming the base metal is Gold (although Copper should give similar selectivity)Copper does etch more readily than Gold both are destroyed by anything with Nitric acid in it.<p>A solder etch bath can be made from 75%(by Vol) Acetic Acid and 25% (by vol) Hydrogen Peroxide (H2O2)(30%). Now that perox...
by haklesup
Mon Mar 03, 2003 5:47 pm
Forum: General Discussion
Topic: generate sensor signal
Replies: 9
Views: 2058

Re: generate sensor signal

"I've heard mechanics say, unplugging sensors for diagnostic purposes was poor diagnostics."<p>It depends on what you are doing. For example if you have a very poorly running engine presumably due to a faulty sensor, then unplugging the bad one may have no effect because it is already bad, unpluggin...
by haklesup
Mon Mar 03, 2003 2:04 pm
Forum: General Discussion
Topic: generate sensor signal
Replies: 9
Views: 2058

Re: generate sensor signal

A half amp (500mA) may be an acceptable current if you just plan to use it intermittantly. I was thinking you wanted a perminant connection to the battery and therefore a low current would prevent premature discharge of the battery while you were parked.<p>I don't know about the car tech's procedure...
by haklesup
Sun Mar 02, 2003 12:27 pm
Forum: General Discussion
Topic: Pulses to control stepper motor
Replies: 11
Views: 1987

Re: Pulses to control stepper motor

You want a divide by 4 digital circuit. You can make one using two JK flip flops (or one Dual). Use a 4027 and you won't have to worry about supply voltage as much. 40xx series logic can run from 3V to 15V<p>Make sure that the pulses from your engine sensor are same or lower voltage than the logic c...
by haklesup
Sun Mar 02, 2003 12:14 pm
Forum: General Discussion
Topic: Daytime running lights
Replies: 1
Views: 926

Re: Daytime running lights

A newer car may have a place to plug a module directly in without extra wiring (as is required in some markets like Canada). Check with the Dodge dealer for the part.<p>Here is a link to a basic module for $10 you can install yourself. http://www.jcwhitney.com/productnoitem.jhtml?CATID=5139&BQ=jcw2....
by haklesup
Sat Mar 01, 2003 11:44 pm
Forum: General Discussion
Topic: small amp ?
Replies: 5
Views: 1069

Re: small amp ?

If the biulding is entirely covered in metal than that is your problem. You are in a fariday cage. You can have the best antenna on a sensitive radio but it is still shielded from the signal. You need to get the antenna outside. <p>Try a simple FM Dipole (T shaped wire) and hook it up to the spring ...
by haklesup
Sat Mar 01, 2003 11:28 pm
Forum: General Discussion
Topic: Producing and Marketing Electronic Inventions
Replies: 13
Views: 2781

Re: Producing and Marketing Electronic Inventions

For packaging, you have a few choices. Easiest and most attractive for low volume are off the shelf enclosures from any number of manufacturers (Bud, Hammond, Oki etc.)Add a custom silkscreened faceplate and metalic sticker or nameplate with your info/logo and you have it. <p>Without knowing anythin...
by haklesup
Fri Feb 28, 2003 3:30 pm
Forum: General Discussion
Topic: Cellular Base Tranceiver ID circuit
Replies: 8
Views: 1609

Re: Cellular Base Tranceiver ID circuit

It is my understanding that you as a civilian may recieve any transmission that you may be able to. The restriction comes when you try to transmit or interfere with said transmissions. You have every right to listen if you can.
by haklesup
Fri Feb 28, 2003 2:01 pm
Forum: General Discussion
Topic: Cellular Base Tranceiver ID circuit
Replies: 8
Views: 1609

Re: Cellular Base Tranceiver ID circuit

There may be a way to modify an existing cell phone to tell you this info.<p>About a month ago someone was posting on this forum looking for used cell phone data trancievers. His website http://www.attdallas.com/information_company.html says that they design value added wireless products. Might try ...
by haklesup
Fri Feb 28, 2003 1:46 pm
Forum: General Discussion
Topic: generate sensor signal
Replies: 9
Views: 2058

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: 1021

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: 1145

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: 1167

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: 680

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...