Search found 37 matches

by viveguy
Fri Oct 07, 2005 4:45 am
Forum: General Discussion
Topic: Analog Electronics books?
Replies: 7
Views: 2310

Re: Analog Electronics books?

Analog Troubleshooting by Robert Pease and Analog Circuit Design by Jim Williams. Both are published by Newnes.
by viveguy
Sun Apr 03, 2005 7:27 am
Forum: General Discussion
Topic: LM317/LT337 questions
Replies: 11
Views: 2487

Re: LM317/LT337 questions

You don't mention the rectifier configuration that you are using. You are going to have a voltage multiplication of 1.414 for a full wave bridge. You can get around the voltage differential problem by putting a zener on the reference (ground) pin. But, that will raise your minimum output voltage.<p>...
by viveguy
Sun Apr 03, 2005 7:26 am
Forum: General Discussion
Topic: LM3914 advice / help
Replies: 9
Views: 2322

Re: LM3914 advice / help

Oops, sorry. I posted to the wrong topic. Another victim of 'sometimers disease'!
by viveguy
Sun Apr 03, 2005 7:23 am
Forum: General Discussion
Topic: LM3914 advice / help
Replies: 9
Views: 2322

Re: LM3914 advice / help

You don't mention the rectifier configuration that you are using. You are going to have a voltage multiplication of 1.414 for a full wave bridge. You can get around the voltage differential problem by putting a zener on the reference (ground) pin. But, that will raise your minimum output voltage.<p>...
by viveguy
Fri Feb 04, 2005 10:50 am
Forum: General Discussion
Topic: current limter
Replies: 8
Views: 2008

Re: current limter

You could also use "toaster wire (nichrome)", like a heat gun element. Some high current lab supplies use this method.
by viveguy
Thu Jan 27, 2005 7:24 am
Forum: General Discussion
Topic: Zener Ckt HELP
Replies: 10
Views: 2790

Re: Zener Ckt HELP

You can use a fixed, 3 terminal regulator for this. Then hang a pre-load resistor about 560 ohms @ .5W across the output. This should keep the voltage from floating high.
by viveguy
Tue Oct 05, 2004 8:45 am
Forum: General Discussion
Topic: Reverb
Replies: 8
Views: 2131

Re: Reverb

Apologies to Edd for my previous post,I addressed the wrong person. I had an attack of 'old timers'. Sorry.
by viveguy
Tue Oct 05, 2004 3:22 am
Forum: General Discussion
Topic: Reverb
Replies: 8
Views: 2131

Re: Reverb

Edd, Spring reverbs are quite common in new gear. They are available in 3 lengths and a number of different I/O impedences. You can get new ones at Mojo tone (www.mojotone.com) or Antique Electronic Supply. They are fairly cheap, typically under $30.00.<p>Input impedences usually range from 8 ohms t...
by viveguy
Wed Jun 30, 2004 9:11 am
Forum: General Discussion
Topic: audio impedance matching/volume control
Replies: 3
Views: 1108

Re: audio impedance matching/volume control

A small transformer and a potentiometer would be the easiest. You can find small,inexpensive transformers at Mouser (mouser.com). You can also find solutions at epanorama.net. Click on the audio links heading.
by viveguy
Wed Jun 30, 2004 3:34 am
Forum: General Discussion
Topic: lightning detector
Replies: 8
Views: 1916

Re: lightning detector

Minor correction to dacflyer's statement. Stormscopes are not radar. I used to build, test and, troubleshoot them for the company that makes them. The antenna consists of a pair of x-y current loops, used for direction finding and a Marconi stub for the E field. When an electrical discharge is detec...
by viveguy
Mon Jan 19, 2004 9:56 am
Forum: General Discussion
Topic: digital speedometer
Replies: 16
Views: 3827

Re: digital speedometer

Try looking at frequency to voltage conversion circuits. I have one in my National Semiconductor Linear Applications book, using the LM1819. You can probably get a pdf at their site, www.national.com. Usually, the cable rotation is sensed by an optical interrupter or Hall effect set-up. This generat...
by viveguy
Mon May 26, 2003 12:10 pm
Forum: General Discussion
Topic: two quickie questions;
Replies: 6
Views: 2050

Re: two quickie questions;

I would surely trade some things with you.I may be able to set you up with some IC's or a chassis.<p>I would be interested in some tubes although,I don't usually go in for used power tubes.BTW,do you still have the chassis?
by viveguy
Thu May 22, 2003 5:56 pm
Forum: General Discussion
Topic: two quickie questions;
Replies: 6
Views: 2050

Re: two quickie questions;

If it was a Hammond B3 with the Leslie,it would be worth more whole.Trying to find a home for an organ nowadays is tough.
Gut it and scrap it I say.But keep the power amplifier chassis.
BTW how much?
by viveguy
Sun Apr 27, 2003 6:01 pm
Forum: General Discussion
Topic: fast high current transistors
Replies: 27
Views: 5901

Re: fast high current transistors

You can try putting a small capacitance from the base to collector,on the order of 10 - 100pF.This is an old technique that has been replaced by schottky devices.Oddly enough these were known as 'speed-up' caps.The capacitor keeps the base-emitter junction from going into saturation. You know,there ...
by viveguy
Thu Mar 13, 2003 5:19 pm
Forum: General Discussion
Topic: Microphones
Replies: 3
Views: 1245

Re: Microphones

Motorola makes some 1" piezo tweeters that are good out to 50 kHz.