Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Quickie => Topic started by: russtafarian on November 25, 2009, 07:49:57 AM

Title: Alternate Battery Hookup Question
Post by: russtafarian on November 25, 2009, 07:49:57 AM
Since I have some SLA batteries lying around, I'd like to try them with my quickie.  Here's what I'm thinking: 12v SLA > 12v SLA > 12v SLA = 36v.  For 1.5v, tap off one of the 12v SLAs and regulate down to 1.5v.

In the kit, the 1.5v D cells are not tied to ground.  Can the 1.5v share the same ground as the 36v or does it need to be isolated?  Thanks.

Russ

Title: Re: Alternate Battery Hookup Question
Post by: Paul Birkeland on November 25, 2009, 08:18:48 AM
Since I have some SLA batteries lying around, I'd like to try them with my quickie.  Here's what I'm thinking: 12v SLA > 12v SLA > 12v SLA = 36v.  For 1.5v, tap off one of the 12v SLAs and regulate down to 1.5v.

In the kit, the 1.5v D cells are not tied to ground.  Can the 1.5v share the same ground as the 36v or does it need to be isolated?  Thanks.

Russ



The 12v stack will work fine to produce the B+ instead of the 9v cells, but sharing grounds between the three supplies will result in no output from the circuit.  Also, regulating 1.5v off the bottom battery will drain it very, very quickly. 

-Paul
Title: Re: Alternate Battery Hookup Question
Post by: Paul Joppa on November 25, 2009, 09:24:14 AM
As PB says, the1.5v batteries are floating for a reason. You could do this with a conversion to fixed bias, but remember the current drain would be 200mA which might drain the SLA pretty fast.
Title: Re: Alternate Battery Hookup Question
Post by: russtafarian on November 30, 2009, 08:46:42 AM
Thanks for the input.  When I get around to trying this (thought I'd have time over Thanksgiving weekend), I'll experiment with three 12V SLAs for the 36V and a separate SLA regulated down for 1.5v.

Russ
Title: Re: Alternate Battery Hookup Question
Post by: Paul Birkeland on November 30, 2009, 01:30:31 PM
Be sure to use two separate regulators to make the 1.5v, one for each channel. 
-PB
Title: Re: Alternate Battery Hookup Question
Post by: russtafarian on December 01, 2009, 06:55:44 AM
Thanks, I'll make sure I use two regulators, one for each tube.