Search found 1555 matches

by dyarker
Wed Dec 17, 2003 7:18 pm
Forum: General Discussion
Topic: High Power Amps - guitar, car, PA, etc.
Replies: 14
Views: 2958

Re: High Power Amps - guitar, car, PA, etc.

Ganged A/B amplifier sections, with outputs isolated/balanced by low Ohm, high power, resistors. (The output of each A/B amp is connected to a resistor, the other ends of the resistors are connected in parallel to feed the speaker(s). Transistors have variations in gain, the resistors help prevent a...
by dyarker
Tue Dec 16, 2003 8:50 pm
Forum: General Discussion
Topic: telephone mystery
Replies: 4
Views: 1037

Re: telephone mystery

Sounds like a Norstar keysystem. What model phone; 7100, 7208, 7100, 2808, 3903, etc.? I'll check my Nortel CDs at work.<p>In the mean time, unplug the phone from the line for a couple minutes. Then select each line and intercom with handset at head, and set the volume. Setting volume with handset i...
by dyarker
Mon Dec 15, 2003 8:02 pm
Forum: General Discussion
Topic: Old post (circuit) problem
Replies: 13
Views: 2006

Re: Old post (circuit) problem

Sorry, I'm going to have to leave you hanging. Still working 12-14 hrs a day 7 days a week. Too tired to analyze this.<p>But I think problem has to do with switch ground on and off.
by dyarker
Sun Dec 14, 2003 9:09 pm
Forum: General Discussion
Topic: Battery test
Replies: 13
Views: 1937

Re: Battery test

What is measured voltage out of charger not connected to battery?<p>What is measured voltage on fully charged battery before, and after, connected to camera (turned off, and turned on)?<p>How did you attach wires to the AA contacts? Wraping would give a high resistance, causing camera to see low on ...
by dyarker
Fri Dec 12, 2003 7:38 pm
Forum: Robotics
Topic: The primative logic operators
Replies: 5
Views: 2473

Re: The primative logic operators

Exclusive OR?
by dyarker
Fri Dec 12, 2003 7:08 pm
Forum: General Discussion
Topic: crystal oscillator questions
Replies: 4
Views: 923

Re: crystal oscillator questions

Yes, that simple. Power in, square wave out. 4 pin oscillator units have crystal, oscillator circuit and output buffer inside.
by dyarker
Thu Dec 11, 2003 8:47 pm
Forum: General Discussion
Topic: smart battery won't charge
Replies: 8
Views: 1209

Re: smart battery won't charge

Then probably time for a new battery.
by dyarker
Wed Dec 10, 2003 8:37 pm
Forum: General Discussion
Topic: smart battery won't charge
Replies: 8
Views: 1209

Re: smart battery won't charge

Does the laptop run when power brick is on AC?<p>Remove and install the battery a couple of times. The contacts may be dirty. In and out may wipe off some crud.<p>By "discharged", do you mean you ran the laptop till it died, or you took the battery out and did something to it?
by dyarker
Tue Dec 09, 2003 7:03 pm
Forum: General Discussion
Topic: Old post (circuit) problem
Replies: 13
Views: 2006

Re: Old post (circuit) problem

Thinking
by dyarker
Mon Dec 08, 2003 9:02 pm
Forum: Computer Programming
Topic: Searching VB databases
Replies: 6
Views: 2772

Re: Searching VB databases

index database on title field.<p>in Access 2K select Query tab, Design button. I think you want FIND FOR (string var passed from VB when it calls the query) IN field title. That's if using COM interface in VB.<p>else, load the database into a 2 dimensional array in VB. then compare the input string ...
by dyarker
Mon Dec 08, 2003 8:34 pm
Forum: Robotics
Topic: IS, WAS and maybe
Replies: 4
Views: 2190

Re: IS, WAS and maybe

Sorry, from the var names and redundant equates I thought you were being humorous. Some kind of philosophical puzzle. --------------------------------------<p>In "WAS is Out = If I = R, M = I, Out = M" It looks like Out = I in any case. And, the var name WAS implies memory where the previous Out is ...
by dyarker
Mon Dec 08, 2003 6:04 pm
Forum: General Discussion
Topic: Old post (circuit) problem
Replies: 13
Views: 2006

Re: Old post (circuit) problem

No ground??
by dyarker
Sun Dec 07, 2003 8:05 pm
Forum: Computer Programming
Topic: Searching VB databases
Replies: 6
Views: 2772

Re: Searching VB databases

Create a dialog, on the dialog put a text box for entering title, a listview box for displaying results, and a button to start the search. Make query to search titles when button is clicked.
by dyarker
Sat Dec 06, 2003 9:49 pm
Forum: General Discussion
Topic: Old post (circuit) problem
Replies: 13
Views: 2006

Re: Old post (circuit) problem

Re: "What is a buffer?"<p>When load power required is greater than available power out of a controller, a buffer or driver cicuit is needed. Basically an it is an amplifier, but not usually called that in ON|OFF situations.<p>For example:<p>Let's say your beeper for this project uses 100mA. A 555 ca...
by dyarker
Sat Dec 06, 2003 8:33 pm
Forum: General Discussion
Topic: Old post (circuit) problem
Replies: 13
Views: 2006

Re: Old post (circuit) problem

A 555 won't work from 1.5V. The wife has hidden my 555 Cookbook; but I think the max Vcc range is 4.5V to 18V, with best results at 10V to 15V.<p>So now I think the problem is the supply voltage. Change back to 12V battery.<p>To prevent the 1.5V alarm clock beeper from burning up, put a resistor bet...