Laser pointer discussion. Read/write reviews of laser pointers and laser pointer companies. Learn about all types of laser pointers and lasers





Welcome to Laser Pointer Forums! If you are looking for a laser pointer or want to compare different laser pointer companies, you may want to check out the LPF Laser Pointer Company Database. The link will open in a new window for your convenience.








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes
Laser Technology Laser Pointer Parts Lasers by Wavelength
Top 10 Laser Pointer Companies Laser Pointer Company Database Visible Beam Laser Pointers


One laser store meets all your needs

























Go Back   Laser Pointer Forums - Discuss Laser Pointers > Lasers > Drivers, Test-load, Power Supply, & Batteries



LPF List of Laser Pointer Companies (link opens new window)



Reply
 
LinkBack Thread Tools Display Modes
Old 09-05-2014, 02:27 AM #1
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
delciotto delciotto is offline
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
Default Automatic low voltage shut off circuit.

Anyone got a schematic for a simple low voltage shutoff? I have a project I'll be building soon that uses 4 18650 unprotected batteries and I want a small circuit to stop the battery pack from going below 12V so they don't get damaged. The circuit it will be powering will be drawing around 3.5A too if it matters.



Last edited by delciotto; 09-05-2014 at 02:29 AM.
delciotto is offline   Reply With Quote







LPF List of Laser Pointer Companies (link opens new window)







Old 09-05-2014, 04:12 AM #2
Cyparagon's Avatar
Class 4 Laser
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,142
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Cyparagon Cyparagon is online now
Class 4 Laser
Cyparagon's Avatar
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,142
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Default Re: Automatic low voltage shut off circuit.

What are you powering, and how good with electronics are you?
__________________
A problem well stated is a problem half solved.
Cyparagon is online now   Reply With Quote
Old 09-05-2014, 04:16 AM #3
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
delciotto delciotto is offline
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
Default Re: Automatic low voltage shut off circuit.

Quote:
Originally Posted by Cyparagon View Post
What are you powering, and how good with electronics are you?
I'm a trained wireless communications/electronics technician, but I can't design for shit. If I have a schematic I can make a PCB from it and build it or fix it. Although it's been a couple years since I've had to use those skills.

Its going to power a high wattage LED lamp driver.

Last edited by delciotto; 09-05-2014 at 04:18 AM.
delciotto is offline   Reply With Quote
Old 09-05-2014, 11:37 PM #4
The Lightning Stalker's Avatar
Class 3B Laser
 
Join Date: Aug 2013
Location: MI, US
Posts: 2,654
Rep Power: 716
The Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond repute
The Lightning Stalker The Lightning Stalker is offline
Class 3B Laser
The Lightning Stalker's Avatar
 
Join Date: Aug 2013
Location: MI, US
Posts: 2,654
Rep Power: 716
The Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond repute
Default Re: Automatic low voltage shut off circuit.

Try this.

__________________
ALL NEW MEMBERS MUST READ THIS!!! --> http://www.laserpointersafety.com

"Where, now, is the way by which the light distributes itself" - Job 38:24

YouTube Channel
The Lightning Stalker is offline   Reply With Quote
Old 09-05-2014, 11:59 PM #5
Cyparagon's Avatar
Class 4 Laser
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,142
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Cyparagon Cyparagon is online now
Class 4 Laser
Cyparagon's Avatar
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,142
Rep Power: 9321
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Default Re: Automatic low voltage shut off circuit.

There are many ways to do this. Here's one I picked from google images that would work, and is one of the simplest:



Have the "12V" come from the battery, and have the power to the driver go through the relay. The parasitic draw would be quite high, >100mA which would drain your pack in a couple days, so your power switch should probably go in series with the relay coil. Add a flyback diode (google it) to the coil. This would lower your parasitic draw to ~3mA which isn't too bad.

Add a volt or so to the zener value to figure your cutoff voltage. 12V zener would cut the voltage off a bit over 13V. 10V zener would cut if off a bit over 11V etc.

Before anyone jumps on me with "USE A FET YOU MORON " I'll point out that I'm going for simplicity. Gate drive is a lot more picky than coil drive, and adding the needed hysteresis to the system complicates things.
__________________
A problem well stated is a problem half solved.
Cyparagon is online now   Reply With Quote
Old 09-06-2014, 12:15 AM #6
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
delciotto delciotto is offline
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
Default Re: Automatic low voltage shut off circuit.

Quote:
Originally Posted by Cyparagon View Post
There are many ways to do this. Here's one I picked from google images that would work, and is one of the simplest:



Have the "12V" come from the battery, and have the power to the driver go through the relay. The parasitic draw would be quite high, >100mA which would drain your pack in a couple days, so your power switch should probably go in series with the relay coil. Add a flyback diode (google it) to the coil. This would lower your parasitic draw to ~3mA which isn't too bad.

Add a volt or so to the zener value to figure your cutoff voltage. 12V zener would cut the voltage off a bit over 13V. 10V zener would cut if off a bit over 11V etc.

Before anyone jumps on me with "USE A FET YOU MORON " I'll point out that I'm going for simplicity. Gate drive is a lot more picky than coil drive, and adding the needed hysteresis to the system complicates things.
Well time to dig through my parts and see if i got that transistor. I know i have some darlington transistors somewhere in my mess of parts, just don't know what ones.
delciotto is offline   Reply With Quote
Old 09-06-2014, 01:21 AM #7
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
delciotto delciotto is offline
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
Default Re: Automatic low voltage shut off circuit.

Well in my search through my parts i didn't have the transistor i needed and the local electronics shop doesn't have them, but i did find some IRF510s and a bunch of 2N2906s and a 3.7V zener which I was able to make this circuit with



Which worked great, I should be able to replace that zener with a 10-12V and it should work fine still.

I also found a baggy full of LM317Ts, so if I want to make a bunch of laser drivers i guess I'm good to go lol
delciotto is offline   Reply With Quote
Old 09-06-2014, 07:35 AM #8
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
delciotto delciotto is offline
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
Default Re: Automatic low voltage shut off circuit.

Oh man i just realised i'm going to need a crazy dummy load for this when i calibrate the driver since its going to be powering a 100W LED lamp at 30-36V. I only have experience with making RF dummy loads and from a quick glance at google one for something like this is a lot different. Looks like a whole bunch of diodes to simulate the voltage drop and a MASSIVE 1 ohm load resistor.

Last edited by delciotto; 09-06-2014 at 07:35 AM.
delciotto is offline   Reply With Quote
Old 09-06-2014, 01:46 PM #9
The Lightning Stalker's Avatar
Class 3B Laser
 
Join Date: Aug 2013
Location: MI, US
Posts: 2,654
Rep Power: 716
The Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond repute
The Lightning Stalker The Lightning Stalker is offline
Class 3B Laser
The Lightning Stalker's Avatar
 
Join Date: Aug 2013
Location: MI, US
Posts: 2,654
Rep Power: 716
The Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond repute
Default Re: Automatic low voltage shut off circuit.

I would say just forget about the dummy
load. LEDs are far more tolerant of current
spikes and ESD than laser diodes. In this
case a dummy load would cost more than
the LED, so just use the LED for testing.

For the resistor, you can use one of these or
a shunt ammeter.

------> WNDR10FET <-----
__________________
ALL NEW MEMBERS MUST READ THIS!!! --> http://www.laserpointersafety.com

"Where, now, is the way by which the light distributes itself" - Job 38:24

YouTube Channel
The Lightning Stalker is offline   Reply With Quote
Old 09-07-2014, 07:38 AM #10
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
delciotto delciotto is offline
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
Default Re: Automatic low voltage shut off circuit.

Ha ha! The protection circuit works great! Time for some pics.

The soldered circuit on a solderable breadboard


Testing, it works!




I also discovered I REALLY need a bigger work area.
delciotto is offline   Reply With Quote
Old 09-07-2014, 04:57 PM #11
The Lightning Stalker's Avatar
Class 3B Laser
 
Join Date: Aug 2013
Location: MI, US
Posts: 2,654
Rep Power: 716
The Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond repute
The Lightning Stalker The Lightning Stalker is offline
Class 3B Laser
The Lightning Stalker's Avatar
 
Join Date: Aug 2013
Location: MI, US
Posts: 2,654
Rep Power: 716
The Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond reputeThe Lightning Stalker has a reputation beyond repute
Default Re: Automatic low voltage shut off circuit.

Very nice. You have constructed your own
op-amp from discretes. What happened to
the zener diode?
__________________
ALL NEW MEMBERS MUST READ THIS!!! --> http://www.laserpointersafety.com

"Where, now, is the way by which the light distributes itself" - Job 38:24

YouTube Channel
The Lightning Stalker is offline   Reply With Quote
Old 09-07-2014, 05:04 PM #12
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
delciotto delciotto is offline
Member
 
Join Date: Aug 2014
Location: British Columbia, Canada
Posts: 31
Rep Power: 0
delciotto is a jewel in the roughdelciotto is a jewel in the roughdelciotto is a jewel in the rough
Default Re: Automatic low voltage shut off circuit.

Quote:
Originally Posted by The Lightning Stalker View Post
Very nice. You have constructed your own
op-amp from discretes. What happened to
the zener diode?
Yeah I looked up ones with discrete components because I didn't feel like waiting for shipping again and i knew i had those parts around. and the zener is under the blue resistor.

Last edited by delciotto; 09-07-2014 at 05:05 PM.
delciotto is offline   Reply With Quote
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
Trackbacks are On
Pingbacks are On
Refbacks are On











Loading








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes






Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 03:59 AM.


Powered by: vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC