Low battery indicator for active guitar & bass 3V-36V £15 Bangor

[zvirus 26]

 Hi

 

!!! Are You  familiar with basic electronics and soldering and understand this device needs to be switched off when NOT IN USE?? !!!

No need to be installed on a bass.. You can remove battery and test it outside the bass... if its still ok the led will not lit up(!)

 

 Worrying about dead battery in the middle of a tune on a gig?  - You do not have to any more with this circuit!

 

It works with 9V battery (or 2 of them) and It can be set up via trimmer resistor to indicate any voltage between 3V and 36V

You can choose the voltage which will lit the led.  

EMG, Bartolini, Seymour Duncan and others use 9 volt batteries and its recommended to set it to 7.7V

My Stagg EUB still works ok when 4V and above (4-9V range)

• Blue Led 3mm diameter
• Indicating range 3.0-36V - Can be set using small flat screwdriver and you will need adjustable DC Power supply - I can set it to any Voltage from 3V to 18V (in example 7.7V) DO NOT WORRY  - I`ll DO THIS FOR YOU!
• Current Draw(power consumption) approx 0.01A(10mA) @9V - when led is not lit - please note: THIS IS THE LOWEST DRAW I COULD ACHIEVE FROM BASIC ELECTRONIC PARTS. ANYTHING BASED ON DIODES WILL DRAW MUCH MUCH MORE(!!!) I did my lesson.
• As EVERY electronic device it will drain your battery if not switched off after you finished using bass or guitar

 

 

When the voltage drops lets say below 6.5V(in this example) the led will lit up as shown in my video:

 

 

 

£15 + £2.69 Signed/tracked Postage 1st Class UK  Posted same day if paid by 3pm

For an extra £2 I can attach/solder MICRO switch - the one you can see on some active bass guitars

 

 

 

How to install? You will know if you have the skill...

 

 

 

Edited November 27, 2020 by zvirus

[cloudburst 7]

Cool!  Are you in Bangor NI or Bangor Wales?

CB

[zvirus 26]

Norn Iron - sometimes known as Northern Ireland... 😁

[cloudburst 7]

4 hours ago, zvirus said:

Norn Iron - sometimes known as Northern Ireland... 😁

Ha! I’m in Ballyholme. 🙂

CB

[stewblack 5,509]

Hi, excuse me for being dense. But where is the light when it's all assembled? 

Do you have a picture of the bass with this attached? 

Thanks 

[zvirus 26]

20 hours ago, stewblack said:

Hi, excuse me for being dense. But where is the light when it's all assembled? 

Do you have a picture of the bass with this attached? 

Thanks 

Well.... Im afraid you have to use Imagination and drill 3mm hole in a plastic/wooden cover you might have in your bass/guitar  and use glue or buy this:

Personally I`d use tiny bit of super glue to hold it in that drilled hole...

I have installed this in my stagg but used The led factory mounted so - no difference in front panel... = nothing to show..

looks like this:

When battery goes down the led changes colour  and I know it`s time... to change...

Edited May 29, 2020 by zvirus

[stewblack 5,509]

Thanks for the reply. I couldn't quite picture how it mounted on the bass. I guess it all depends on the model of the instrument. 

Clever idea though. 

[mcnach 2,715]

Interesting!

Can the threshold voltage be user-adjusted with a simple multimeter? I'm wondering whether this would be a good idea for a bass I've got with active EMG pickups. There's no 'bypass switch' possibility for those, only replacing batteries before they go bad, so an early warning would be nice. The thing is I am not sure what threshold to set, so I'd probably like to play around with it a little which will require further adjustments in time.

[zvirus 26]

Hi.

As described. You can set desired voltage by turning screw and read voltage on meter and watch when led goes on....or off

 

 

Cheers!

Edited October 21, 2020 by zvirus

[pbasspecial 375]

Here’s mine done. 

[mcnach 2,715]

16 hours ago, zvirus said:

Hi.

As described. You can set desired voltage by turning screw and read voltage on meter and watch when led goes on....or off

 

 

Cheers!

 

Oh I see, for some reason yesterday only two of the images were showing. Thanks!

It sounds as 'though even someone like me could manage that

Thread bookmarked. Now I need to figure out where to install the LED and switch. I'm about to rewire the bass (well, I've been about to rewire it for months now :D) as I want to remove the 2-band preamp and install a passive tone control with an active semiparametric mids module (everything already bought from EMG). It's tight (small metal control plate with three knobs already) but I think I should find room.

[JohnDaBass 294]

Ordered one of these to try on my Fender FSR Seafoam green PJ.

Update once fitted.