Generators and Motors
[Home] - [HELP] - [Forums] - [Library] - [Photo Gallery] - [Groups] - [Classified Ads] - [Subscribe] - [Links] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Vintage Electrical Equipment > Generators & Electric Motors General Discussion
Forgot Password? Join Us!

Notices

Generators & Electric Motors General Discussion Antique Generators and Old Electric Motors: Questions and answers about restoring and showing old power generation systems.

Generators & Electric Motors General Discussion

Automatic Voltage Regulators


this thread has 33 replies and has been viewed 3045 times

Reply
 
Thread Tools Display Modes
  #11  
Old 05-06-2018, 08:43:41 PM
Vanman Vanman is offline
Subscriber
 
Join Date: Aug 2011
Location: Mission Viejo, California
Posts: 4,573
Thanks: 5,933
Thanked 1,945 Times in 1,332 Posts
Default Re: Automatic Voltage Regulators

Funny thing about the little neon lamps. I hadn't seen one blow up, but, knowing their characteristics, I had my suspicions.

So, when a friend was getting ready to plug one in, he noticed that I was backing up lol. He said, "what?". I just grinned and said, "Plug it in and see!". We were both pleasantly surprised by the magnitude of the POP!
Reply With Quote
Sponsored Links
  #12  
Old 05-06-2018, 11:49:02 PM
Thaumaturge Thaumaturge is offline
Subscriber
 
Join Date: Mar 2014
Location: Beryl, Utah USA
Posts: 3,831
Thanks: 2,900
Thanked 3,859 Times in 1,625 Posts
Default Re: Automatic Voltage Regulators

Yah, figure that quarter ohm ionized resistance across 120VAC RMS works out to just over 21 Amps or about 1800 Watts* concentrated inside that little glass envelope. That rather suddenly increases the gas pressure inside the bulb.... not to mention the arc that contnues to discharge between the poles until they get blown far enough apart for the ionization of just the inrush atmosphere to fall off after the neon scatters.

The way I knew they would blow up you could easily guess....
Doc

*~170V P-P /2 = ~85V peak per half cycle
__________________
NOW my chest hair decides to grow?
Reply With Quote
  #13  
Old 05-07-2018, 05:16:45 AM
Elden DuRand's Avatar
Elden DuRand Elden DuRand is offline
Subscriber
 
Join Date: Nov 2004
Location: Port St. Joe, Florida, USA
Posts: 7,778
Thanks: 12,928
Thanked 7,544 Times in 2,935 Posts
Images: 11
Default Re: Automatic Voltage Regulators

Since I'm definitely not an expert on gensets, I thought I'd jump-in here with my non-expertise.

If an engineer designs a voltage regulator that would self destruct during an ordinary event (genset stopping while under load - running out of fuel), he should be re-tasked with sweeping the parking lot.

Intermittent brushes, dirty commutators and slip rings, uneven loads, etc. should also be considered when designing the regulator.

In other words, it isn't rocket science to design and build a robust voltage regulator, whether it be for a DC supply or a genset.

Maybe the bean counters are getting into the act.

Oh, yes - the NE-2 lamps used as surge suppressors work well as long as the energy they dissipate is small. Varistors are the choice today.
__________________

Take care - Elden
http://www.eldensengines.com
Reply With Quote
The Following User Says Thank You to Elden DuRand For This Post:
  #14  
Old 05-07-2018, 06:24:26 AM
armandh armandh is offline
Sponsor
 
Join Date: Aug 2006
Location: Suburban St. Louis, Missouri
Posts: 2,953
Thanks: 234
Thanked 773 Times in 604 Posts
Default Re: Automatic Voltage Regulators

that post #6 reference left the building I add it here
Attached Thumbnails
Click image for larger version

Name:	img483.jpg
Views:	45
Size:	145.7 KB
ID:	309884   Click image for larger version

Name:	img484.jpg
Views:	25
Size:	87.3 KB
ID:	309885  
Attached Files
File Type: pdf 25120-bw.pdf (80.4 KB, 19 views)
__________________
.
by using this free advise, you, your heirs, etc
absolve, save, and hold harmless the advisor.
CAVEAT EMPTOR
YMMV

Last edited by armandh; 05-07-2018 at 07:14:16 PM.
Reply With Quote
The Following 3 Users Say Thank You to armandh For This Post:
  #15  
Old 05-07-2018, 06:31:03 AM
armandh armandh is offline
Sponsor
 
Join Date: Aug 2006
Location: Suburban St. Louis, Missouri
Posts: 2,953
Thanks: 234
Thanked 773 Times in 604 Posts
Default Re: Automatic Voltage Regulators

getting outside the closed loop

VR and slip ring problems are simple [IMHO]
my take on this
first engine start in a while....
load goes on voltage goes down,
sensed by VR which increases voltage to the field
tarnished slip rings prevent increase in field current
causing the VR output to go max
tarnish is worn off and load slaps on the maxed output
sudden current exceeds component rating
magic smoke escapes
__________________
.
by using this free advise, you, your heirs, etc
absolve, save, and hold harmless the advisor.
CAVEAT EMPTOR
YMMV

Last edited by armandh; 05-07-2018 at 06:57:42 AM.
Reply With Quote
  #16  
Old 05-07-2018, 06:45:20 AM
Thaumaturge Thaumaturge is offline
Subscriber
 
Join Date: Mar 2014
Location: Beryl, Utah USA
Posts: 3,831
Thanks: 2,900
Thanked 3,859 Times in 1,625 Posts
Default Re: Automatic Voltage Regulators

My entry for a bullit proof AVR design. Assumes ground referenced aux supply rectified and positive fed to other side of field. Transformer primary is wired to select 120 or 240 input. Trimmers set 1 VAC into RMS converter and internal reference to set output. Transistors are thermally linked on heatsink. If output overheats LM395 automatically shuts down. Only assembly difficulty is RMS converter ONLY available in tiny little surface mount dip package.
Doc
Attached Thumbnails
Click image for larger version

Name:	Screenshot_2018-05-07-04-29-18.jpg
Views:	55
Size:	117.2 KB
ID:	309891  
__________________
NOW my chest hair decides to grow?
Reply With Quote
The Following 2 Users Say Thank You to Thaumaturge For This Post:
  #17  
Old 05-07-2018, 06:35:22 PM
Elden DuRand's Avatar
Elden DuRand Elden DuRand is offline
Subscriber
 
Join Date: Nov 2004
Location: Port St. Joe, Florida, USA
Posts: 7,778
Thanks: 12,928
Thanked 7,544 Times in 2,935 Posts
Images: 11
Default Re: Automatic Voltage Regulators

Quote:
Originally Posted by armandh View Post
that reference left the building I add it here
Ahh, yes! I remember well the Signetics Write Only Memory. They ran ads in some of the engineering rags and actually garnered some interest.

It was a good joke!
__________________

Take care - Elden
http://www.eldensengines.com
Reply With Quote
  #18  
Old 05-07-2018, 07:15:55 PM
armandh armandh is offline
Sponsor
 
Join Date: Aug 2006
Location: Suburban St. Louis, Missouri
Posts: 2,953
Thanks: 234
Thanked 773 Times in 604 Posts
Default Re: Automatic Voltage Regulators

I think the ad ran in 4-1-1973 editions
__________________
.
by using this free advise, you, your heirs, etc
absolve, save, and hold harmless the advisor.
CAVEAT EMPTOR
YMMV
Reply With Quote
  #19  
Old 05-07-2018, 11:07:42 PM
Zeromedic Zeromedic is offline
Subscriber
 
Join Date: May 2005
Location: Michigan, USA
Posts: 351
Thanks: 95
Thanked 324 Times in 169 Posts
Default Re: Automatic Voltage Regulators

On the same level as multi-pass floppy disk compression.

Write only memory was the ultimate /dev/null
Attached Thumbnails
Click image for larger version

Name:	wom1.jpg
Views:	30
Size:	165.4 KB
ID:	309979   Click image for larger version

Name:	wom2.jpg
Views:	23
Size:	106.3 KB
ID:	309980  
Reply With Quote
The Following User Says Thank You to Zeromedic For This Post:
  #20  
Old 05-09-2018, 03:03:35 AM
Thaumaturge Thaumaturge is offline
Subscriber
 
Join Date: Mar 2014
Location: Beryl, Utah USA
Posts: 3,831
Thanks: 2,900
Thanked 3,859 Times in 1,625 Posts
Default Re: Automatic Voltage Regulators

(Stubornly sticking to AVR sbject.....)

A few explanations about my AVR design. (Schematic in post #16.)

The transformer; Nothing really special. A little 25va PCB mount will work fine. Dual primary only chosen to give option of sensing either 120 or 240 outputs. But a single primary model of proper voltage will do fine. Note that secondary probably DOES need to be a 12.6 Volt Center tapped, not a 12.0. Reason for that is to feed as high a voltage as possible to the local +/- power supplies. As it is the 5.1 volt zeners are probably not needed, but will serve as clamps for any spikes that might get to them.

Supply voltages will normally be around 4.5 volts or so. Even so that should be quite adequate. The LM10 output will swing within 15mV of rails. Only needs to swing a few volts to turn on LM395.

The LTC1966 was chosen for RMS converter simply for least parts requirement and 1VAC input/1VDC output. AD736 would probably work okay, but only has 200mV input / output. This changes both input and reference scaling.

Initial calibration: Check line voltage with a good true RMS meter. Plug transformer primary into AC line outlet. Connect meter black lead to C1 - terminal. Adjust R8 for 1VRMS at input of LTC1966 with 120VAC on primary. (U2 RMS converter is TINY, so probably easier to measure at junction of R6, R7 & R9.) Should now read 1VDC at U2 output (C1 + lead). Probe pin 1 of U1 (LM10CN) and adjust R4 for 1VDC.
You're done. Install and adj R4 for proper output. (R8 is set once and forget.)

Now... the MAIN reason anybody might bother with this design.... Cheap and pretty much bullit proof! You can buy ALL the parts for $30-$40. If constructed correctly, circuit should protect itself. Q2 LM395 has built in thermal protection. Thermally bonding Q1 to Q2 uses thermal shutdown to protect output. Q1 2SC5200 is rated for about double typical field current and ten times the likely voltage. The back EMF protection diode is way overkill. (Second choice 1N5408, 3A 1000V PIV.)

SO.... COMMENTS?
Doc
__________________
NOW my chest hair decides to grow?
Reply With Quote
The Following 2 Users Say Thank You to Thaumaturge For This Post:
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
Question about older voltage regulators Nazrat Onan Generators 11 04-24-2016 11:21:03 AM
china made voltage regulators any good? YellowLister Onan Generators 19 01-07-2016 05:00:39 PM
What does the REACTOR do on JB and JC late voltage regulators? Motorhead Onan Generators 13 12-10-2015 07:50:34 AM
Feedback on import automatic voltage regulators, like the sx460 CougarMountain Military MEP and Aircraft Gen-Sets 5 08-05-2013 09:04:23 PM
Onan BFG Voltage Regulators? threejeeps Onan Generators 1 05-25-2013 03:03:26 PM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 05:31:46 AM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2016 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277