Question DaftMikes Low-battery Circuit

ByteMe

.
Joined
Apr 16, 2016
Messages
61
Likes
29
Location
Canada
I am wanting to build this, or something similar with two leds, green power indicator and then switches to red led when low voltage occurs. Does anybody have the schematic saved somewhere, all I could find were dead links. Also it suggests any npn transistor, any suggestions on some good general use npn's that would work for this as well (placing an order though digikey) . Thanks
 

Matthew

Formally known as Chaos
.
Joined
Jul 11, 2016
Messages
523
Likes
989
Location
USA
Portables
1
Here is an alternative. It works quite well and for the parts,space, time, and complexity it saves, I recommend it over the other way.
 

ByteMe

.
Joined
Apr 16, 2016
Messages
61
Likes
29
Location
Canada
Thanks, I came across that one as well. I prefer the dual led's just for aesthetic purposes, but I'll consider your alternative.
 

cheese

the tallest memer in town
Staff member
.
.
.
Joined
Mar 2, 2016
Messages
2,758
Likes
2,422
Location
Florida
With this you could also use a RGB led and have the same led be for green and red, just make sure it is a common anode type.
 

ByteMe

.
Joined
Apr 16, 2016
Messages
61
Likes
29
Location
Canada
With this you could also use a RGB led and have the same led be for green and red, just make sure it is a common anode type.
I was hoping to do that, would this one be fine, or do you have a link to a through-hole alternative. I am wanting to sort of backlight a larger area so would two in parallel be fine?

Edit: Fixed Link
 
Last edited:

cheese

the tallest memer in town
Staff member
.
.
.
Joined
Mar 2, 2016
Messages
2,758
Likes
2,422
Location
Florida
I was hoping to do that, would this one be fine, or do you have a link to a through-hole alternative. I am wanting to sort of backlight a larger area so would two in parallel be fine?
Two in parallel would probably be fine, just make sure to drop the resistance of the resistors on the anodes of the LEDs to make up for it. Also that link is just a generic search page, with almost 5m results, gonna have to narrow it down a bit more :P
 

cheese

the tallest memer in town
Staff member
.
.
.
Joined
Mar 2, 2016
Messages
2,758
Likes
2,422
Location
Florida
Yeah that should work fine, it has separate cathode/anode pins for both LEDs so you can wire it up exactly like the schematic (but remember to lower the 1ks to something like 500ohm)
 
Top