Search found 124 matches

by Bern
Sat Mar 04, 2006 1:50 pm
Forum: General Discussion
Topic: Current sensor
Replies: 17
Views: 4170

Re: Current sensor

What I think I would do, is bring out the wires from the two heating elements. Depending on where you are, these will probably be 220 V. Dig around and find a couple of relays that will work, either by themselves or a resistor in series if needed. Maybe use transformers, or what ever you can find in...
by Bern
Sat Mar 04, 2006 9:47 am
Forum: General Discussion
Topic: Frequency Multiplying
Replies: 11
Views: 2487

Re: Frequency Multiplying

Good idea, MrAl. Hadn't even thought of that. Hve done very little with PLLs and that was many many years ago. Maybe time to stretch the grey matter. Will keep looking, but keep that in mind. Thanks
by Bern
Sat Mar 04, 2006 9:34 am
Forum: General Discussion
Topic: Frequency Multiplying
Replies: 11
Views: 2487

Frequency Multiplying

I need about 15 KC, locked to the power line frequency. -- Thinking about taking the 60 cycle and several stages of frequency doublers. This will keep the 15 KC locked to the power line. -- Looking for ideas using a minimum number of parts. Since there are several stages, prefer not to have to have ...
by Bern
Sun Jan 15, 2006 9:15 pm
Forum: General Discussion
Topic: Schematic software
Replies: 5
Views: 1497

Re: Schematic software

For small projects, I use expresspcb.com and am very pleased with them. They also do a good job on their ($51.00 for three boards) I have some laying next to me, right now that just came in.
by Bern
Sun Jan 15, 2006 9:01 pm
Forum: General Discussion
Topic: Side view LED ?
Replies: 3
Views: 899

Side view LED ?

You people are great. I am getting all kinds of good info. Now I need a 360-degree, side view, bright LED. ---- I have a box sitting about four feet high, with a light sticking out the top. When it is on, it needs to be seen from all directions. Normally an incandescent lamp would work great, but I ...
by Bern
Sun Jan 15, 2006 7:30 pm
Forum: General Discussion
Topic: Resistor Noise?
Replies: 13
Views: 2326

Re: Resistor Noise?

Robert, They will be going into the front end of an Op Amp circuit. I'm looking at micro-volts riding on 100s of millivots. Freq. between about ten and fifty KC. Needless to say, I want to minimize noise.
by Bern
Sun Jan 15, 2006 3:28 pm
Forum: General Discussion
Topic: Resistor Noise?
Replies: 13
Views: 2326

Re: Resistor Noise?

Yep Dean, I remember those. I quit Tek. in 1969, after being in final test and then suport Eng.
by Bern
Sat Jan 14, 2006 8:23 pm
Forum: General Discussion
Topic: Resistor Noise?
Replies: 13
Views: 2326

Re: Resistor Noise?

I think I answered my own question. Did some more digging and found an excellent explanation under Guitar Amps. Sorry for the bother. See; http://www.aikenamps.com/ResistorNoise.htm
by Bern
Sat Jan 14, 2006 8:01 pm
Forum: General Discussion
Topic: Resistor Noise?
Replies: 13
Views: 2326

Resistor Noise?

Designing a circuit where I am concerned about noise. Question: Are todays real cheap resistors noisier than some other types? I know years ago we watched the type of resistors we used in some tube grid circuits, but I don’t know about today’s resistors. If you wanted a very low noise resistor, what...
by Bern
Tue Jan 03, 2006 4:07 pm
Forum: General Discussion
Topic: Data Finding Site ?
Replies: 1
Views: 645

Data Finding Site ?

I have run out of ideas of where to look. There are several sites I use to find data, but this device has me stopped. Trying to find info. on a “KT05”. Underneath is “E4YC”, maybe a date code. -- It is in a TO92 style package. It is in a vary strange filter circuit that does not make sense, if it is...
by Bern
Thu Dec 29, 2005 5:09 pm
Forum: General Discussion
Topic: Variable R. Switch
Replies: 6
Views: 1582

Re: Variable R. Switch

jimandy, that is exactly what I am loking for. However, I hope to find someone who mass produces them. I am sure they can build them cheaper and more reliable than what I want to bother with. --- jwax, that is one of the areas I looked at. That would do the job, only this product will be on for mont...
by Bern
Thu Dec 29, 2005 1:55 pm
Forum: General Discussion
Topic: Variable R. Switch
Replies: 6
Views: 1582

Re: Variable R. Switch

Thanks, dacflyer, but that is not quite what I am looking for. I did not do a good job of explaining what I wanted, but philba figured it out. I need a force transducer, like in his first reference. Thanks philba, I made contact with them and waiting for their return. It appears like they have just ...
by Bern
Wed Dec 28, 2005 10:49 pm
Forum: General Discussion
Topic: Variable R. Switch
Replies: 6
Views: 1582

Variable R. Switch

Anybody ever hear of, and possibly have a source, of small push button switches. I need to have the contact resistance vary with the pressure applied. Maybe have a conductive rubber or plastic pad connected to the contacts. With increased pressure/compression on the pad, the resistance would change....
by Bern
Tue Dec 06, 2005 12:24 am
Forum: General Discussion
Topic: Christmas Lights Tests
Replies: 4
Views: 1219

Re: Christmas Lights Tests

I built one very similar to this one several years ago. I used two flash light batteries to power the “drive” box. I used a CMOS gate to generate about a 20 KC square wave, and drove two outputs, out of phase. A standard AC receptacle in the small plastic box, and just plug in the lights. This drive...
by Bern
Thu Nov 24, 2005 12:37 pm
Forum: General Discussion
Topic: IR sensor
Replies: 23
Views: 4697

Re: IR sensor

Thanks again, Stephen. I very much appreciate your help. The funny thing is that all this time I have had a catalog from All Electronics sitting right next to me. I know I have looked through it, and also their on line catalog, but somehow missed it. I even had ordered some parts from them just a co...