Yeah they are…that’s pretty cool!
This is the one jayrob over at CPF uses on his mag mod with voltmeter in this thread
This is the voltage monitor used
http://www.wr-store.com/product_info.php?cPath=21&products_id=104
HTH
AlexGT
I don’t recall. i came across it some time ago. Its sort of expensive for what it is IMO.
Thanks for the ideas. Helios- Love those links. AlexGT- Yep, that's the thread, Thanks.
These are what I use on some of my spotlight builds. They are smaller at 23mm X 15mm X 10mm, but might fit in a Maglite. They are cheap and work great.
For just a single 3-5mm panel led could you use an op amp and a few resistors? Might fit on a small board ~ 15mm.
Edit-Like this maybe Matt could help you with the board
seems these days programmable drivers offer a lot of flexibility…it might be possible to program one of these drivers to get the functionality needed
re. Star firmware: STAR Firmware by JonnyC - Source Code and Explanation
Looked up the data sheet on the 3.0v voltage monitor linked by Helios and found this schematic
Looks pretty simple to use for just one led.
Thats whats so nice about them. Tiny, easy & uses very little current (0.5 uA typ). Also don’t need to be able to program chips. Just connect the voltage monitor chip, indicator led & resistor (aim for <50mA led current).
Haven’t ordered one yet since the attiny can do low voltage detection.
I ordered one weeks ago, I think it is the smallest, with digits
Whoa that is small - size of a sim card. I looked around - cheapest is $5 shipped for these (vs $1.40 for the bigger guy), quite a jump in price for tinyness.
Interesting why the red is always cheaper than green/blue version - easier to build due to Vf probably?
I like the readout style over the lights. It's larger, but if I can fit it in, I will use the readout style. I don't really need a low voltage warning, I just think a readout of voltage would be kind of different.
Cheapest I could find:
RED:
http://www.ebay.com/itm/0-28-Digital-Panel-Meter-DC-2-5V-30V-Red-LED-Power-Monitor-Lithium-Car-Motor-/251303490316?pt=LH_DefaultDomain_0&hash=item3a82daf30c
Starts as low as 2.5V
YELLOW:
http://www.ebay.com/itm/0-28-Digital-Voltmeter-Power-Monitor-DC-2-6-30V-Voltage-Panel-Meter-Yellow-LED-/390625402570?pt=LH_DefaultDomain_0&hash=item5af3169eca
Starts at 2.6V
Found some better prices now, $1.90 for red to $2.46 for blue:
I don’t think they get cheaper than these. I’m probably going to grab some afterwards. I already have the bigger version in many colours, and I must say the blue LED is the most beautiful - kind of classy, expensive looking.
Dang! Making em smaller and smaller!
The numerical LED blocks are standard size. Three digits is too wide (>20mm). Maybe replace it with two digit block if one decimal place resolution is acceptable?
The ones from gigibaobao are better quality than FastTech, with trim pot and work to lower voltage, but still too big.
Another idea, maybe use two or three of the kind Helios posted set to different voltages?
It would take an OLED monitor this type of PLX
http://www.plxdevices.com/product_info.php?id=MOBLLEGION055
What do you say to use the monitor like that?? I think you can try!
definitely finding the lowest prices!
http://www.fasttech.com/products/0/10007685/1665901-vstar-s7-0-6-oled-variable-voltage-apv-mod
I never thought of OLED! Gotta research that!
look forward to hearing from you!
I ordered a few of them from Fasttech and they won’t read voltage until it rises above about 3.3 volts. They do work great for RC lipo monitoring & portable solar cell and checking batteries in the field with out lugging a huge Fluke meter.